From 6d80d3c964e7863a42ed3ce95b4917801ed7e7ea Mon Sep 17 00:00:00 2001
From: Silvan Mosberger <contact@infinisil.com>
Date: Wed, 2 Sep 2020 16:10:17 +0200
Subject: [PATCH 01/16] nixos/modules: Allow options to be coerced to a string
 for convenience

---
 lib/modules.nix | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/modules.nix b/lib/modules.nix
index 2468b6fbdd2..cac17a71380 100644
--- a/lib/modules.nix
+++ b/lib/modules.nix
@@ -587,6 +587,8 @@ rec {
         definitions = map (def: def.value) res.defsFinal;
         files = map (def: def.file) res.defsFinal;
         inherit (res) isDefined;
+        # This allows options to be correctly displayed using `${options.path.to.it}`
+        __toString = _: showOption loc;
       };
 
   # Merge definitions of a value of a given type.

From 70b105d1d062369c7489b0045df5a8b86bac5dd6 Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Thu, 25 Nov 2021 21:58:45 +0100
Subject: [PATCH 02/16] nixos/journalbeat: remove support for versions < 6

nixos no longer ships journalbeat 5 and hasn't since at least 20.09. remove
checks for older versions from the module.
---
 nixos/modules/services/logging/journalbeat.nix | 16 +---------------
 1 file changed, 1 insertion(+), 15 deletions(-)

diff --git a/nixos/modules/services/logging/journalbeat.nix b/nixos/modules/services/logging/journalbeat.nix
index 2d98598c1be..1a6473aed08 100644
--- a/nixos/modules/services/logging/journalbeat.nix
+++ b/nixos/modules/services/logging/journalbeat.nix
@@ -5,14 +5,10 @@ with lib;
 let
   cfg = config.services.journalbeat;
 
-  lt6 = builtins.compareVersions cfg.package.version "6" < 0;
-
   journalbeatYml = pkgs.writeText "journalbeat.yml" ''
     name: ${cfg.name}
     tags: ${builtins.toJSON cfg.tags}
 
-    ${optionalString lt6 "journalbeat.cursor_state_file: /var/lib/${cfg.stateDir}/cursor-state"}
-
     ${cfg.extraConfig}
   '';
 
@@ -58,17 +54,7 @@ in
 
       extraConfig = mkOption {
         type = types.lines;
-        default = optionalString lt6 ''
-          journalbeat:
-            seek_position: cursor
-            cursor_seek_fallback: tail
-            write_cursor_state: true
-            cursor_flush_period: 5s
-            clean_field_names: true
-            convert_to_numbers: false
-            move_metadata_to_field: journal
-            default_type: journal
-        '';
+        default = "";
         description = "Any other configuration options you want to add";
       };
 

From e24a8775a86905ad001c4c965a7d180b41c10c52 Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Sun, 5 Dec 2021 20:40:24 +0100
Subject: [PATCH 03/16] treewide: set defaultText for options using simple path
 defaults

adds defaultText for all options that set their default to a path expression
using the ubiquitous `cfg` shortcut bindings.
---
 nixos/modules/config/networking.nix                   | 8 +++++++-
 nixos/modules/hardware/system-76.nix                  | 8 ++++++--
 nixos/modules/misc/version.nix                        | 4 +++-
 nixos/modules/programs/zsh/zsh.nix                    | 4 +++-
 nixos/modules/security/acme.nix                       | 2 ++
 nixos/modules/security/dhparams.nix                   | 6 ++++--
 nixos/modules/services/cluster/kubernetes/default.nix | 4 +++-
 nixos/modules/services/cluster/kubernetes/kubelet.nix | 3 ++-
 nixos/modules/services/computing/slurm/slurm.nix      | 5 ++++-
 nixos/modules/services/misc/etcd.nix                  | 8 +++++++-
 nixos/modules/services/misc/gitlab.nix                | 4 +++-
 nixos/modules/services/misc/mwlib.nix                 | 4 +++-
 nixos/modules/services/misc/rippled.nix               | 5 ++++-
 nixos/modules/services/monitoring/smartd.nix          | 4 +++-
 nixos/modules/services/networking/ergo.nix            | 6 ++++--
 nixos/modules/services/networking/quorum.nix          | 4 +++-
 nixos/modules/services/networking/wasabibackend.nix   | 6 ++++--
 nixos/modules/services/video/epgstation/default.nix   | 4 +++-
 nixos/modules/services/web-apps/discourse.nix         | 2 ++
 nixos/modules/services/web-apps/peertube.nix          | 4 +++-
 nixos/modules/services/x11/hardware/synaptics.nix     | 7 ++++++-
 21 files changed, 79 insertions(+), 23 deletions(-)

diff --git a/nixos/modules/config/networking.nix b/nixos/modules/config/networking.nix
index 11307e33120..133a150df82 100644
--- a/nixos/modules/config/networking.nix
+++ b/nixos/modules/config/networking.nix
@@ -1,12 +1,13 @@
 # /etc files related to networking, such as /etc/services.
 
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
 
   cfg = config.networking;
+  opt = options.networking;
 
   localhostMultiple = any (elem "localhost") (attrValues (removeAttrs cfg.hosts [ "127.0.0.1" "::1" ]));
 
@@ -78,6 +79,7 @@ in
       httpProxy = lib.mkOption {
         type = types.nullOr types.str;
         default = cfg.proxy.default;
+        defaultText = literalExpression "config.${opt.proxy.default}";
         description = ''
           This option specifies the http_proxy environment variable.
         '';
@@ -87,6 +89,7 @@ in
       httpsProxy = lib.mkOption {
         type = types.nullOr types.str;
         default = cfg.proxy.default;
+        defaultText = literalExpression "config.${opt.proxy.default}";
         description = ''
           This option specifies the https_proxy environment variable.
         '';
@@ -96,6 +99,7 @@ in
       ftpProxy = lib.mkOption {
         type = types.nullOr types.str;
         default = cfg.proxy.default;
+        defaultText = literalExpression "config.${opt.proxy.default}";
         description = ''
           This option specifies the ftp_proxy environment variable.
         '';
@@ -105,6 +109,7 @@ in
       rsyncProxy = lib.mkOption {
         type = types.nullOr types.str;
         default = cfg.proxy.default;
+        defaultText = literalExpression "config.${opt.proxy.default}";
         description = ''
           This option specifies the rsync_proxy environment variable.
         '';
@@ -114,6 +119,7 @@ in
       allProxy = lib.mkOption {
         type = types.nullOr types.str;
         default = cfg.proxy.default;
+        defaultText = literalExpression "config.${opt.proxy.default}";
         description = ''
           This option specifies the all_proxy environment variable.
         '';
diff --git a/nixos/modules/hardware/system-76.nix b/nixos/modules/hardware/system-76.nix
index d4896541dba..ca40ee0ebb3 100644
--- a/nixos/modules/hardware/system-76.nix
+++ b/nixos/modules/hardware/system-76.nix
@@ -1,8 +1,9 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 let
-  inherit (lib) mkOption mkEnableOption types mkIf mkMerge optional versionOlder;
+  inherit (lib) literalExpression mkOption mkEnableOption types mkIf mkMerge optional versionOlder;
   cfg = config.hardware.system76;
+  opt = options.hardware.system76;
 
   kpkgs = config.boot.kernelPackages;
   modules = [ "system76" "system76-io" ] ++ (optional (versionOlder kpkgs.kernel.version "5.5") "system76-acpi");
@@ -60,6 +61,7 @@ in {
 
       firmware-daemon.enable = mkOption {
         default = cfg.enableAll;
+        defaultText = literalExpression "config.${opt.enableAll}";
         example = true;
         description = "Whether to enable the system76 firmware daemon";
         type = types.bool;
@@ -67,6 +69,7 @@ in {
 
       kernel-modules.enable = mkOption {
         default = cfg.enableAll;
+        defaultText = literalExpression "config.${opt.enableAll}";
         example = true;
         description = "Whether to make the system76 out-of-tree kernel modules available";
         type = types.bool;
@@ -74,6 +77,7 @@ in {
 
       power-daemon.enable = mkOption {
         default = cfg.enableAll;
+        defaultText = literalExpression "config.${opt.enableAll}";
         example = true;
         description = "Whether to enable the system76 power daemon";
         type = types.bool;
diff --git a/nixos/modules/misc/version.nix b/nixos/modules/misc/version.nix
index 8f246a9278b..fc0d65d5148 100644
--- a/nixos/modules/misc/version.nix
+++ b/nixos/modules/misc/version.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.system.nixos;
+  opt = options.system.nixos;
 in
 
 {
@@ -53,6 +54,7 @@ in
     stateVersion = mkOption {
       type = types.str;
       default = cfg.release;
+      defaultText = literalExpression "config.${opt.release}";
       description = ''
         Every once in a while, a new NixOS release may change
         configuration defaults in a way incompatible with stateful
diff --git a/nixos/modules/programs/zsh/zsh.nix b/nixos/modules/programs/zsh/zsh.nix
index e5c5b08f8d4..5fe98b6801b 100644
--- a/nixos/modules/programs/zsh/zsh.nix
+++ b/nixos/modules/programs/zsh/zsh.nix
@@ -1,6 +1,6 @@
 # This module defines global configuration for the zshell.
 
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
@@ -9,6 +9,7 @@ let
   cfge = config.environment;
 
   cfg = config.programs.zsh;
+  opt = options.programs.zsh;
 
   zshAliases = concatStringsSep "\n" (
     mapAttrsFlatten (k: v: "alias ${k}=${escapeShellArg v}")
@@ -147,6 +148,7 @@ in
 
       enableGlobalCompInit = mkOption {
         default = cfg.enableCompletion;
+        defaultText = literalExpression "config.${opt.enableCompletion}";
         description = ''
           Enable execution of compinit call for all interactive zsh shells.
 
diff --git a/nixos/modules/security/acme.nix b/nixos/modules/security/acme.nix
index 2815e2593b2..25e04f2effc 100644
--- a/nixos/modules/security/acme.nix
+++ b/nixos/modules/security/acme.nix
@@ -2,6 +2,7 @@
 with lib;
 let
   cfg = config.security.acme;
+  opt = options.security.acme;
 
   # Used to calculate timer accuracy for coalescing
   numCerts = length (builtins.attrNames cfg.certs);
@@ -470,6 +471,7 @@ let
       email = mkOption {
         type = types.nullOr types.str;
         default = cfg.email;
+        defaultText = literalExpression "config.${opt.email}";
         description = "Contact email address for the CA to be able to reach you.";
       };
 
diff --git a/nixos/modules/security/dhparams.nix b/nixos/modules/security/dhparams.nix
index 012be2887d8..cfa9003f12f 100644
--- a/nixos/modules/security/dhparams.nix
+++ b/nixos/modules/security/dhparams.nix
@@ -1,8 +1,9 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 let
-  inherit (lib) mkOption types;
+  inherit (lib) literalExpression mkOption types;
   cfg = config.security.dhparams;
+  opt = options.security.dhparams;
 
   bitType = types.addCheck types.int (b: b >= 16) // {
     name = "bits";
@@ -13,6 +14,7 @@ let
     options.bits = mkOption {
       type = bitType;
       default = cfg.defaultBitSize;
+      defaultText = literalExpression "config.${opt.defaultBitSize}";
       description = ''
         The bit size for the prime that is used during a Diffie-Hellman
         key exchange.
diff --git a/nixos/modules/services/cluster/kubernetes/default.nix b/nixos/modules/services/cluster/kubernetes/default.nix
index 433adf4d488..cf7fcb0a6d7 100644
--- a/nixos/modules/services/cluster/kubernetes/default.nix
+++ b/nixos/modules/services/cluster/kubernetes/default.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.kubernetes;
+  opt = options.services.kubernetes;
 
   defaultContainerdSettings = {
     version = 2;
@@ -87,6 +88,7 @@ let
       description = "${prefix} certificate authority file used to connect to kube-apiserver.";
       type = types.nullOr types.path;
       default = cfg.caFile;
+      defaultText = literalExpression "config.${opt.caFile}";
     };
 
     certFile = mkOption {
diff --git a/nixos/modules/services/cluster/kubernetes/kubelet.nix b/nixos/modules/services/cluster/kubernetes/kubelet.nix
index eb0cb1f3dbc..7ecc4fd45b7 100644
--- a/nixos/modules/services/cluster/kubernetes/kubelet.nix
+++ b/nixos/modules/services/cluster/kubernetes/kubelet.nix
@@ -1,4 +1,4 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
@@ -76,6 +76,7 @@ in
     clusterDomain = mkOption {
       description = "Use alternative domain.";
       default = config.services.kubernetes.addons.dns.clusterDomain;
+      defaultText = literalExpression "config.${options.services.kubernetes.addons.dns.clusterDomain}";
       type = str;
     };
 
diff --git a/nixos/modules/services/computing/slurm/slurm.nix b/nixos/modules/services/computing/slurm/slurm.nix
index 0c96f323132..02dfe2fe882 100644
--- a/nixos/modules/services/computing/slurm/slurm.nix
+++ b/nixos/modules/services/computing/slurm/slurm.nix
@@ -1,10 +1,11 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
 
   cfg = config.services.slurm;
+  opt = options.services.slurm;
   # configuration file can be generated by http://slurm.schedmd.com/configurator.html
 
   defaultUser = "slurm";
@@ -89,6 +90,7 @@ in
         storageUser = mkOption {
           type = types.str;
           default = cfg.user;
+          defaultText = literalExpression "config.${opt.user}";
           description = ''
             Database user name.
           '';
@@ -153,6 +155,7 @@ in
       controlAddr = mkOption {
         type = types.nullOr types.str;
         default = cfg.controlMachine;
+        defaultText = literalExpression "config.${opt.controlMachine}";
         example = null;
         description = ''
           Name that ControlMachine should be referred to in establishing a
diff --git a/nixos/modules/services/misc/etcd.nix b/nixos/modules/services/misc/etcd.nix
index c4ea091a038..fc6dfaa4285 100644
--- a/nixos/modules/services/misc/etcd.nix
+++ b/nixos/modules/services/misc/etcd.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.etcd;
+  opt = options.services.etcd;
 
 in {
 
@@ -23,6 +24,7 @@ in {
     advertiseClientUrls = mkOption {
       description = "Etcd list of this member's client URLs to advertise to the rest of the cluster.";
       default = cfg.listenClientUrls;
+      defaultText = literalExpression "config.${opt.listenClientUrls}";
       type = types.listOf types.str;
     };
 
@@ -41,6 +43,7 @@ in {
     initialAdvertisePeerUrls = mkOption {
       description = "Etcd list of this member's peer URLs to advertise to rest of the cluster.";
       default = cfg.listenPeerUrls;
+      defaultText = literalExpression "config.${opt.listenPeerUrls}";
       type = types.listOf types.str;
     };
 
@@ -95,18 +98,21 @@ in {
     peerCertFile = mkOption {
       description = "Cert file to use for peer to peer communication";
       default = cfg.certFile;
+      defaultText = literalExpression "config.${opt.certFile}";
       type = types.nullOr types.path;
     };
 
     peerKeyFile = mkOption {
       description = "Key file to use for peer to peer communication";
       default = cfg.keyFile;
+      defaultText = literalExpression "config.${opt.keyFile}";
       type = types.nullOr types.path;
     };
 
     peerTrustedCaFile = mkOption {
       description = "Certificate authority file to use for peer to peer communication";
       default = cfg.trustedCaFile;
+      defaultText = literalExpression "config.${opt.trustedCaFile}";
       type = types.nullOr types.path;
     };
 
diff --git a/nixos/modules/services/misc/gitlab.nix b/nixos/modules/services/misc/gitlab.nix
index b2abe70627d..cc924163ef0 100644
--- a/nixos/modules/services/misc/gitlab.nix
+++ b/nixos/modules/services/misc/gitlab.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, utils, ... }:
+{ config, lib, options, pkgs, utils, ... }:
 
 with lib;
 
 let
   cfg = config.services.gitlab;
+  opt = options.services.gitlab;
 
   ruby = cfg.packages.gitlab.ruby;
 
@@ -552,6 +553,7 @@ in {
         defaultForProjects = mkOption {
           type = types.bool;
           default = cfg.registry.enable;
+          defaultText = literalExpression "config.${opt.registry.enable}";
           description = "If GitLab container registry should be enabled by default for projects.";
         };
         issuer = mkOption {
diff --git a/nixos/modules/services/misc/mwlib.nix b/nixos/modules/services/misc/mwlib.nix
index 8dd17c06c0b..ec8ecee8423 100644
--- a/nixos/modules/services/misc/mwlib.nix
+++ b/nixos/modules/services/misc/mwlib.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.mwlib;
+  opt = options.services.mwlib;
   pypkgs = pkgs.python27Packages;
 
   inherit (pypkgs) python mwlib;
@@ -96,6 +97,7 @@ in
     nslave = {
       enable = mkOption {
         default = cfg.qserve.enable;
+        defaultText = literalExpression "config.${opt.qserve.enable}";
         type = types.bool;
         description = ''
           Pulls new jobs from exactly one qserve instance
diff --git a/nixos/modules/services/misc/rippled.nix b/nixos/modules/services/misc/rippled.nix
index 9c66df2fce1..67768a97bfb 100644
--- a/nixos/modules/services/misc/rippled.nix
+++ b/nixos/modules/services/misc/rippled.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.rippled;
+  opt = options.services.rippled;
 
   b2i = val: if val then "1" else "0";
 
@@ -165,6 +166,7 @@ let
         description = "Location to store the database.";
         type = types.path;
         default = cfg.databasePath;
+        defaultText = literalExpression "config.${opt.databasePath}";
       };
 
       compression = mkOption {
@@ -177,6 +179,7 @@ let
         description = "Enable automatic purging of older ledger information.";
         type = types.nullOr (types.addCheck types.int (v: v > 256));
         default = cfg.ledgerHistory;
+        defaultText = literalExpression "config.${opt.ledgerHistory}";
       };
 
       advisoryDelete = mkOption {
diff --git a/nixos/modules/services/monitoring/smartd.nix b/nixos/modules/services/monitoring/smartd.nix
index 3ea25437114..793791c4c12 100644
--- a/nixos/modules/services/monitoring/smartd.nix
+++ b/nixos/modules/services/monitoring/smartd.nix
@@ -1,4 +1,4 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
@@ -8,6 +8,7 @@ let
        + optionalString (config.networking.domain != null) ".${config.networking.domain}";
 
   cfg = config.services.smartd;
+  opt = options.services.smartd;
 
   nm = cfg.notifications.mail;
   nw = cfg.notifications.wall;
@@ -208,6 +209,7 @@ in
 
         autodetected = mkOption {
           default = cfg.defaults.monitored;
+          defaultText = literalExpression "config.${opt.defaults.monitored}";
           type = types.separatedString " ";
           description = ''
             Like <option>services.smartd.defaults.monitored</option>, but for the
diff --git a/nixos/modules/services/networking/ergo.nix b/nixos/modules/services/networking/ergo.nix
index c52de30dc36..6e55a7cfff6 100644
--- a/nixos/modules/services/networking/ergo.nix
+++ b/nixos/modules/services/networking/ergo.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 let
   cfg = config.services.ergo;
+  opt = options.services.ergo;
 
-  inherit (lib) mkEnableOption mkIf mkOption optionalString types;
+  inherit (lib) literalExpression mkEnableOption mkIf mkOption optionalString types;
 
   configFile = pkgs.writeText "ergo.conf" (''
 ergo {
@@ -92,6 +93,7 @@ in {
       group = mkOption {
         type = types.str;
         default = cfg.user;
+        defaultText = literalExpression "config.${opt.user}";
         description = "The group as which to run the Ergo node.";
       };
 
diff --git a/nixos/modules/services/networking/quorum.nix b/nixos/modules/services/networking/quorum.nix
index 50148dc314d..bddcd18c7fb 100644
--- a/nixos/modules/services/networking/quorum.nix
+++ b/nixos/modules/services/networking/quorum.nix
@@ -1,9 +1,10 @@
-{ config, pkgs, lib, ... }:
+{ config, options, pkgs, lib, ... }:
 let
 
   inherit (lib) mkEnableOption mkIf mkOption literalExpression types optionalString;
 
   cfg = config.services.quorum;
+  opt = options.services.quorum;
   dataDir = "/var/lib/quorum";
   genesisFile = pkgs.writeText "genesis.json" (builtins.toJSON cfg.genesis);
   staticNodesFile = pkgs.writeText "static-nodes.json" (builtins.toJSON cfg.staticNodes);
@@ -23,6 +24,7 @@ in {
       group = mkOption {
         type = types.str;
         default = cfg.user;
+        defaultText = literalExpression "config.${opt.user}";
         description = "The group as which to run quorum.";
       };
 
diff --git a/nixos/modules/services/networking/wasabibackend.nix b/nixos/modules/services/networking/wasabibackend.nix
index 8482823e197..b6dcd940915 100644
--- a/nixos/modules/services/networking/wasabibackend.nix
+++ b/nixos/modules/services/networking/wasabibackend.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 let
   cfg = config.services.wasabibackend;
+  opt = options.services.wasabibackend;
 
-  inherit (lib) mkEnableOption mkIf mkOption optionalAttrs optionalString types;
+  inherit (lib) literalExpression mkEnableOption mkIf mkOption optionalAttrs optionalString types;
 
   confOptions = {
       BitcoinRpcConnectionString = "${cfg.rpc.user}:${cfg.rpc.password}";
@@ -103,6 +104,7 @@ in {
       group = mkOption {
         type = types.str;
         default = cfg.user;
+        defaultText = literalExpression "config.${opt.user}";
         description = "The group as which to run the wasabibackend node.";
       };
     };
diff --git a/nixos/modules/services/video/epgstation/default.nix b/nixos/modules/services/video/epgstation/default.nix
index 36f7b937d5a..f895a1bfed1 100644
--- a/nixos/modules/services/video/epgstation/default.nix
+++ b/nixos/modules/services/video/epgstation/default.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.epgstation;
+  opt = options.services.epgstation;
 
   username = config.users.users.epgstation.name;
   groupname = config.users.users.epgstation.group;
@@ -80,6 +81,7 @@ in
     clientSocketioPort = mkOption {
       type = types.port;
       default = cfg.socketioPort;
+      defaultText = literalExpression "config.${opt.socketioPort}";
       description = ''
         Socket.io port that the web client is going to connect to. This may be
         different from <option>socketioPort</option> if EPGStation is hidden
diff --git a/nixos/modules/services/web-apps/discourse.nix b/nixos/modules/services/web-apps/discourse.nix
index c4fb7e2b316..e128e88cfad 100644
--- a/nixos/modules/services/web-apps/discourse.nix
+++ b/nixos/modules/services/web-apps/discourse.nix
@@ -4,6 +4,7 @@ let
   json = pkgs.formats.json {};
 
   cfg = config.services.discourse;
+  opt = options.services.discourse;
 
   # Keep in sync with https://github.com/discourse/discourse_docker/blob/master/image/base/Dockerfile#L5
   upstreamPostgresqlVersion = lib.getVersion pkgs.postgresql_13;
@@ -399,6 +400,7 @@ in
           domain = lib.mkOption {
             type = lib.types.str;
             default = cfg.hostname;
+            defaultText = lib.literalExpression "config.${opt.hostname}";
             description = ''
               HELO domain to use for outgoing mail.
             '';
diff --git a/nixos/modules/services/web-apps/peertube.nix b/nixos/modules/services/web-apps/peertube.nix
index 362a3358b79..a9473fb8178 100644
--- a/nixos/modules/services/web-apps/peertube.nix
+++ b/nixos/modules/services/web-apps/peertube.nix
@@ -1,7 +1,8 @@
-{ lib, pkgs, config, ... }:
+{ lib, pkgs, config, options, ... }:
 
 let
   cfg = config.services.peertube;
+  opt = options.services.peertube;
 
   settingsFormat = pkgs.formats.json {};
   configFile = settingsFormat.generate "production.json" cfg.settings;
@@ -212,6 +213,7 @@ in {
       enableUnixSocket = lib.mkOption {
         type = lib.types.bool;
         default = cfg.redis.createLocally;
+        defaultText = lib.literalExpression "config.${opt.redis.createLocally}";
         description = "Use Unix socket.";
       };
     };
diff --git a/nixos/modules/services/x11/hardware/synaptics.nix b/nixos/modules/services/x11/hardware/synaptics.nix
index 22af869f1f8..93dd560bca4 100644
--- a/nixos/modules/services/x11/hardware/synaptics.nix
+++ b/nixos/modules/services/x11/hardware/synaptics.nix
@@ -1,8 +1,9 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let cfg = config.services.xserver.synaptics;
+    opt = options.services.xserver.synaptics;
     tapConfig = if cfg.tapButtons then enabledTapConfig else disabledTapConfig;
     enabledTapConfig = ''
       Option "MaxTapTime" "180"
@@ -77,24 +78,28 @@ in {
       horizTwoFingerScroll = mkOption {
         type = types.bool;
         default = cfg.twoFingerScroll;
+        defaultText = literalExpression "config.${opt.twoFingerScroll}";
         description = "Whether to enable horizontal two-finger drag-scrolling.";
       };
 
       vertTwoFingerScroll = mkOption {
         type = types.bool;
         default = cfg.twoFingerScroll;
+        defaultText = literalExpression "config.${opt.twoFingerScroll}";
         description = "Whether to enable vertical two-finger drag-scrolling.";
       };
 
       horizEdgeScroll = mkOption {
         type = types.bool;
         default = ! cfg.horizTwoFingerScroll;
+        defaultText = literalExpression "! config.${opt.horizTwoFingerScroll}";
         description = "Whether to enable horizontal edge drag-scrolling.";
       };
 
       vertEdgeScroll = mkOption {
         type = types.bool;
         default = ! cfg.vertTwoFingerScroll;
+        defaultText = literalExpression "! config.${opt.vertTwoFingerScroll}";
         description = "Whether to enable vertical edge drag-scrolling.";
       };
 

From f6d0b014fe1db9e6edec5485f41a1162136c8a70 Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Sun, 5 Dec 2021 20:48:56 +0100
Subject: [PATCH 04/16] nixos/kubernetes: add defaultText for addons options
 using top.*

the kubernetes modules cross-reference their config using an additional shortcut
binding `top = config.services.kubernetes`, expand those to defaultText like
`cfg` previously.
---
 nixos/modules/services/cluster/kubernetes/apiserver.nix    | 7 ++++++-
 .../services/cluster/kubernetes/controller-manager.nix     | 6 +++++-
 nixos/modules/services/cluster/kubernetes/kubelet.nix      | 3 +++
 nixos/modules/services/cluster/kubernetes/proxy.nix        | 4 +++-
 nixos/modules/services/cluster/kubernetes/scheduler.nix    | 4 +++-
 5 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/nixos/modules/services/cluster/kubernetes/apiserver.nix b/nixos/modules/services/cluster/kubernetes/apiserver.nix
index 2c89310beb5..5b97c571d76 100644
--- a/nixos/modules/services/cluster/kubernetes/apiserver.nix
+++ b/nixos/modules/services/cluster/kubernetes/apiserver.nix
@@ -1,9 +1,10 @@
-  { config, lib, pkgs, ... }:
+  { config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   top = config.services.kubernetes;
+  otop = options.services.kubernetes;
   cfg = top.apiserver;
 
   isRBACEnabled = elem "RBAC" cfg.authorizationMode;
@@ -84,6 +85,7 @@ in
     clientCaFile = mkOption {
       description = "Kubernetes apiserver CA file for client auth.";
       default = top.caFile;
+      defaultText = literalExpression "config.${otop.caFile}";
       type = nullOr path;
     };
 
@@ -138,6 +140,7 @@ in
       caFile = mkOption {
         description = "Etcd ca file.";
         default = top.caFile;
+        defaultText = literalExpression "config.${otop.caFile}";
         type = types.nullOr types.path;
       };
     };
@@ -157,6 +160,7 @@ in
     featureGates = mkOption {
       description = "List set of feature gates";
       default = top.featureGates;
+      defaultText = literalExpression "config.${otop.featureGates}";
       type = listOf str;
     };
 
@@ -175,6 +179,7 @@ in
     kubeletClientCaFile = mkOption {
       description = "Path to a cert file for connecting to kubelet.";
       default = top.caFile;
+      defaultText = literalExpression "config.${otop.caFile}";
       type = nullOr path;
     };
 
diff --git a/nixos/modules/services/cluster/kubernetes/controller-manager.nix b/nixos/modules/services/cluster/kubernetes/controller-manager.nix
index 7128b5f70b1..ed25715fab7 100644
--- a/nixos/modules/services/cluster/kubernetes/controller-manager.nix
+++ b/nixos/modules/services/cluster/kubernetes/controller-manager.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   top = config.services.kubernetes;
+  otop = options.services.kubernetes;
   cfg = top.controllerManager;
 in
 {
@@ -30,6 +31,7 @@ in
     clusterCidr = mkOption {
       description = "Kubernetes CIDR Range for Pods in cluster.";
       default = top.clusterCidr;
+      defaultText = literalExpression "config.${otop.clusterCidr}";
       type = str;
     };
 
@@ -44,6 +46,7 @@ in
     featureGates = mkOption {
       description = "List set of feature gates";
       default = top.featureGates;
+      defaultText = literalExpression "config.${otop.featureGates}";
       type = listOf str;
     };
 
@@ -67,6 +70,7 @@ in
         service account's token secret.
       '';
       default = top.caFile;
+      defaultText = literalExpression "config.${otop.caFile}";
       type = nullOr path;
     };
 
diff --git a/nixos/modules/services/cluster/kubernetes/kubelet.nix b/nixos/modules/services/cluster/kubernetes/kubelet.nix
index 7ecc4fd45b7..4c00e162efa 100644
--- a/nixos/modules/services/cluster/kubernetes/kubelet.nix
+++ b/nixos/modules/services/cluster/kubernetes/kubelet.nix
@@ -4,6 +4,7 @@ with lib;
 
 let
   top = config.services.kubernetes;
+  otop = options.services.kubernetes;
   cfg = top.kubelet;
 
   cniConfig =
@@ -83,6 +84,7 @@ in
     clientCaFile = mkOption {
       description = "Kubernetes apiserver CA file for client authentication.";
       default = top.caFile;
+      defaultText = literalExpression "config.${otop.caFile}";
       type = nullOr path;
     };
 
@@ -149,6 +151,7 @@ in
     featureGates = mkOption {
       description = "List set of feature gates";
       default = top.featureGates;
+      defaultText = literalExpression "config.${otop.featureGates}";
       type = listOf str;
     };
 
diff --git a/nixos/modules/services/cluster/kubernetes/proxy.nix b/nixos/modules/services/cluster/kubernetes/proxy.nix
index a92043d5259..3f3683650a4 100644
--- a/nixos/modules/services/cluster/kubernetes/proxy.nix
+++ b/nixos/modules/services/cluster/kubernetes/proxy.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   top = config.services.kubernetes;
+  otop = options.services.kubernetes;
   cfg = top.proxy;
 in
 {
@@ -31,6 +32,7 @@ in
     featureGates = mkOption {
       description = "List set of feature gates";
       default = top.featureGates;
+      defaultText = literalExpression "config.${otop.featureGates}";
       type = listOf str;
     };
 
diff --git a/nixos/modules/services/cluster/kubernetes/scheduler.nix b/nixos/modules/services/cluster/kubernetes/scheduler.nix
index 1b0c22a1142..87263ee72fa 100644
--- a/nixos/modules/services/cluster/kubernetes/scheduler.nix
+++ b/nixos/modules/services/cluster/kubernetes/scheduler.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   top = config.services.kubernetes;
+  otop = options.services.kubernetes;
   cfg = top.scheduler;
 in
 {
@@ -27,6 +28,7 @@ in
     featureGates = mkOption {
       description = "List set of feature gates";
       default = top.featureGates;
+      defaultText = literalExpression "config.${otop.featureGates}";
       type = listOf str;
     };
 

From fb0e5be84331188a69b3edd31679ca6576edb75a Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Sun, 5 Dec 2021 21:28:49 +0100
Subject: [PATCH 05/16] treewide: add defaultText for options with simple
 interpolation defaults

adds defaultText for all options that use `cfg.*` values in their
defaults, but only for interpolations with no extra processing (other
than toString where necessary)
---
 .../modules/services/cluster/hadoop/default.nix | 14 +++++++++++++-
 .../continuous-integration/buildbot/master.nix  |  4 +++-
 .../continuous-integration/buildbot/worker.nix  |  4 +++-
 .../gocd-agent/default.nix                      | 12 +++++++++++-
 .../gocd-server/default.nix                     | 17 ++++++++++++++++-
 nixos/modules/services/databases/neo4j.nix      |  5 +++++
 nixos/modules/services/hardware/tcsd.nix        |  6 +++++-
 nixos/modules/services/misc/etcd.nix            |  1 +
 nixos/modules/services/misc/exhibitor.nix       |  5 ++++-
 nixos/modules/services/misc/gitea.nix           |  8 +++++++-
 nixos/modules/services/misc/gogs.nix            |  5 ++++-
 nixos/modules/services/misc/headphones.nix      |  4 +++-
 .../services/misc/matrix-appservice-discord.nix |  4 +++-
 nixos/modules/services/misc/mwlib.nix           |  8 ++++++--
 nixos/modules/services/misc/sickbeard.nix       |  4 +++-
 .../modules/services/misc/sourcehut/builds.nix  |  4 +++-
 .../services/misc/sourcehut/dispatch.nix        |  4 +++-
 nixos/modules/services/misc/sourcehut/git.nix   |  4 +++-
 nixos/modules/services/misc/sourcehut/hg.nix    |  4 +++-
 nixos/modules/services/misc/sourcehut/hub.nix   |  4 +++-
 nixos/modules/services/misc/sourcehut/lists.nix |  4 +++-
 nixos/modules/services/misc/sourcehut/man.nix   |  4 +++-
 nixos/modules/services/misc/sourcehut/meta.nix  |  4 +++-
 nixos/modules/services/misc/sourcehut/paste.nix |  4 +++-
 nixos/modules/services/misc/sourcehut/todo.nix  |  4 +++-
 nixos/modules/services/monitoring/grafana.nix   |  1 +
 nixos/modules/services/monitoring/graphite.nix  |  5 ++++-
 nixos/modules/services/security/privacyidea.nix |  6 +++++-
 nixos/modules/services/torrent/peerflix.nix     |  4 +++-
 nixos/modules/services/torrent/rtorrent.nix     |  4 +++-
 nixos/modules/services/video/unifi-video.nix    |  4 +++-
 31 files changed, 136 insertions(+), 29 deletions(-)

diff --git a/nixos/modules/services/cluster/hadoop/default.nix b/nixos/modules/services/cluster/hadoop/default.nix
index 90f22c48e05..a1a95fe31ca 100644
--- a/nixos/modules/services/cluster/hadoop/default.nix
+++ b/nixos/modules/services/cluster/hadoop/default.nix
@@ -1,6 +1,7 @@
-{ config, lib, pkgs, ...}:
+{ config, lib, options, pkgs, ...}:
 let
   cfg = config.services.hadoop;
+  opt = options.services.hadoop;
 in
 with lib;
 {
@@ -44,6 +45,14 @@ with lib;
         "mapreduce.map.env" = "HADOOP_MAPRED_HOME=${cfg.package}/lib/${cfg.package.untarDir}";
         "mapreduce.reduce.env" = "HADOOP_MAPRED_HOME=${cfg.package}/lib/${cfg.package.untarDir}";
       };
+      defaultText = literalExpression ''
+        {
+          "mapreduce.framework.name" = "yarn";
+          "yarn.app.mapreduce.am.env" = "HADOOP_MAPRED_HOME=''${config.${opt.package}}/lib/''${config.${opt.package}.untarDir}";
+          "mapreduce.map.env" = "HADOOP_MAPRED_HOME=''${config.${opt.package}}/lib/''${config.${opt.package}.untarDir}";
+          "mapreduce.reduce.env" = "HADOOP_MAPRED_HOME=''${config.${opt.package}}/lib/''${config.${opt.package}.untarDir}";
+        }
+      '';
       type = types.attrsOf types.anything;
       example = literalExpression ''
         options.services.hadoop.mapredSite.default // {
@@ -98,6 +107,9 @@ with lib;
 
     log4jProperties = mkOption {
       default = "${cfg.package}/lib/${cfg.package.untarDir}/etc/hadoop/log4j.properties";
+      defaultText = literalExpression ''
+        "''${config.${opt.package}}/lib/''${config.${opt.package}.untarDir}/etc/hadoop/log4j.properties"
+      '';
       type = types.path;
       example = literalExpression ''
         "''${pkgs.hadoop}/lib/''${pkgs.hadoop.untarDir}/etc/hadoop/log4j.properties";
diff --git a/nixos/modules/services/continuous-integration/buildbot/master.nix b/nixos/modules/services/continuous-integration/buildbot/master.nix
index 2dc61c21ac7..aaa159d3cb1 100644
--- a/nixos/modules/services/continuous-integration/buildbot/master.nix
+++ b/nixos/modules/services/continuous-integration/buildbot/master.nix
@@ -1,11 +1,12 @@
 # NixOS module for Buildbot continous integration server.
 
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.buildbot-master;
+  opt = options.services.buildbot-master;
 
   python = cfg.package.pythonModule;
 
@@ -152,6 +153,7 @@ in {
 
       buildbotDir = mkOption {
         default = "${cfg.home}/master";
+        defaultText = literalExpression ''"''${config.${opt.home}}/master"'';
         type = types.path;
         description = "Specifies the Buildbot directory.";
       };
diff --git a/nixos/modules/services/continuous-integration/buildbot/worker.nix b/nixos/modules/services/continuous-integration/buildbot/worker.nix
index dd4f4a4a74a..1d7f53bb655 100644
--- a/nixos/modules/services/continuous-integration/buildbot/worker.nix
+++ b/nixos/modules/services/continuous-integration/buildbot/worker.nix
@@ -1,11 +1,12 @@
 # NixOS module for Buildbot Worker.
 
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.buildbot-worker;
+  opt = options.services.buildbot-worker;
 
   python = cfg.package.pythonModule;
 
@@ -77,6 +78,7 @@ in {
 
       buildbotDir = mkOption {
         default = "${cfg.home}/worker";
+        defaultText = literalExpression ''"''${config.${opt.home}}/worker"'';
         type = types.path;
         description = "Specifies the Buildbot directory.";
       };
diff --git a/nixos/modules/services/continuous-integration/gocd-agent/default.nix b/nixos/modules/services/continuous-integration/gocd-agent/default.nix
index acc3fb12484..c63998c6736 100644
--- a/nixos/modules/services/continuous-integration/gocd-agent/default.nix
+++ b/nixos/modules/services/continuous-integration/gocd-agent/default.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.gocd-agent;
+  opt = options.services.gocd-agent;
 in {
   options = {
     services.gocd-agent = {
@@ -98,6 +99,15 @@ in {
           "-Dcruise.console.publish.interval=10"
           "-Djava.security.egd=file:/dev/./urandom"
         ];
+        defaultText = literalExpression ''
+          [
+            "-Xms''${config.${opt.initialJavaHeapSize}}"
+            "-Xmx''${config.${opt.maxJavaHeapMemory}}"
+            "-Djava.io.tmpdir=/tmp"
+            "-Dcruise.console.publish.interval=10"
+            "-Djava.security.egd=file:/dev/./urandom"
+          ]
+        '';
         description = ''
           Specifies startup command line arguments to pass to Go.CD agent
           java process.
diff --git a/nixos/modules/services/continuous-integration/gocd-server/default.nix b/nixos/modules/services/continuous-integration/gocd-server/default.nix
index 646bf13ac67..3540656f934 100644
--- a/nixos/modules/services/continuous-integration/gocd-server/default.nix
+++ b/nixos/modules/services/continuous-integration/gocd-server/default.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.gocd-server;
+  opt = options.services.gocd-server;
 in {
   options = {
     services.gocd-server = {
@@ -106,6 +107,20 @@ in {
           "-Dcruise.server.port=${toString cfg.port}"
           "-Dcruise.server.ssl.port=${toString cfg.sslPort}"
         ];
+        defaultText = literalExpression ''
+          [
+            "-Xms''${config.${opt.initialJavaHeapSize}}"
+            "-Xmx''${config.${opt.maxJavaHeapMemory}}"
+            "-Dcruise.listen.host=''${config.${opt.listenAddress}}"
+            "-Duser.language=en"
+            "-Djruby.rack.request.size.threshold.bytes=30000000"
+            "-Duser.country=US"
+            "-Dcruise.config.dir=''${config.${opt.workDir}}/conf"
+            "-Dcruise.config.file=''${config.${opt.workDir}}/conf/cruise-config.xml"
+            "-Dcruise.server.port=''${toString config.${opt.port}}"
+            "-Dcruise.server.ssl.port=''${toString config.${opt.sslPort}}"
+          ]
+        '';
 
         description = ''
           Specifies startup command line arguments to pass to Go.CD server
diff --git a/nixos/modules/services/databases/neo4j.nix b/nixos/modules/services/databases/neo4j.nix
index f37e5ad1693..b258d698664 100644
--- a/nixos/modules/services/databases/neo4j.nix
+++ b/nixos/modules/services/databases/neo4j.nix
@@ -4,6 +4,7 @@ with lib;
 
 let
   cfg = config.services.neo4j;
+  opt = options.services.neo4j;
   certDirOpt = options.services.neo4j.directories.certificates;
   isDefaultPathOption = opt: isOption opt && opt.type == types.path && opt.highestPrio >= 1500;
 
@@ -256,6 +257,7 @@ in {
       certificates = mkOption {
         type = types.path;
         default = "${cfg.directories.home}/certificates";
+        defaultText = literalExpression ''"''${config.${opt.directories.home}}/certificates"'';
         description = ''
           Directory for storing certificates to be used by Neo4j for
           TLS connections.
@@ -280,6 +282,7 @@ in {
       data = mkOption {
         type = types.path;
         default = "${cfg.directories.home}/data";
+        defaultText = literalExpression ''"''${config.${opt.directories.home}}/data"'';
         description = ''
           Path of the data directory. You must not configure more than one
           Neo4j installation to use the same data directory.
@@ -305,6 +308,7 @@ in {
       imports = mkOption {
         type = types.path;
         default = "${cfg.directories.home}/import";
+        defaultText = literalExpression ''"''${config.${opt.directories.home}}/import"'';
         description = ''
           The root directory for file URLs used with the Cypher
           <literal>LOAD CSV</literal> clause. Only meaningful when
@@ -321,6 +325,7 @@ in {
       plugins = mkOption {
         type = types.path;
         default = "${cfg.directories.home}/plugins";
+        defaultText = literalExpression ''"''${config.${opt.directories.home}}/plugins"'';
         description = ''
           Path of the database plugin directory. Compiled Java JAR files that
           contain database procedures will be loaded if they are placed in
diff --git a/nixos/modules/services/hardware/tcsd.nix b/nixos/modules/services/hardware/tcsd.nix
index c549a677501..e414b9647c9 100644
--- a/nixos/modules/services/hardware/tcsd.nix
+++ b/nixos/modules/services/hardware/tcsd.nix
@@ -1,11 +1,12 @@
 # tcsd daemon.
 
-{ config, pkgs, lib, ... }:
+{ config, options, pkgs, lib, ... }:
 
 with lib;
 let
 
   cfg = config.services.tcsd;
+  opt = options.services.tcsd;
 
   tcsdConf = pkgs.writeText "tcsd.conf" ''
     port = 30003
@@ -83,6 +84,7 @@ in
 
       platformCred = mkOption {
         default = "${cfg.stateDir}/platform.cert";
+        defaultText = literalExpression ''"''${config.${opt.stateDir}}/platform.cert"'';
         type = types.path;
         description = ''
           Path to the platform credential for your TPM. Your TPM
@@ -96,6 +98,7 @@ in
 
       conformanceCred = mkOption {
         default = "${cfg.stateDir}/conformance.cert";
+        defaultText = literalExpression ''"''${config.${opt.stateDir}}/conformance.cert"'';
         type = types.path;
         description = ''
           Path to the conformance credential for your TPM.
@@ -104,6 +107,7 @@ in
 
       endorsementCred = mkOption {
         default = "${cfg.stateDir}/endorsement.cert";
+        defaultText = literalExpression ''"''${config.${opt.stateDir}}/endorsement.cert"'';
         type = types.path;
         description = ''
           Path to the endorsement credential for your TPM.
diff --git a/nixos/modules/services/misc/etcd.nix b/nixos/modules/services/misc/etcd.nix
index fc6dfaa4285..88920d6a28e 100644
--- a/nixos/modules/services/misc/etcd.nix
+++ b/nixos/modules/services/misc/etcd.nix
@@ -50,6 +50,7 @@ in {
     initialCluster = mkOption {
       description = "Etcd initial cluster configuration for bootstrapping.";
       default = ["${cfg.name}=http://127.0.0.1:2380"];
+      defaultText = literalExpression ''["''${config.${opt.name}}=http://127.0.0.1:2380"]'';
       type = types.listOf types.str;
     };
 
diff --git a/nixos/modules/services/misc/exhibitor.nix b/nixos/modules/services/misc/exhibitor.nix
index 28c98edf47a..4c935efbd84 100644
--- a/nixos/modules/services/misc/exhibitor.nix
+++ b/nixos/modules/services/misc/exhibitor.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.exhibitor;
+  opt = options.services.exhibitor;
   exhibitorConfig = ''
     zookeeper-install-directory=${cfg.baseDir}/zookeeper
     zookeeper-data-directory=${cfg.zkDataDir}
@@ -165,6 +166,7 @@ in
       zkDataDir = mkOption {
         type = types.str;
         default = "${cfg.baseDir}/zkData";
+        defaultText = literalExpression ''"''${config.${opt.baseDir}}/zkData"'';
         description = ''
           The Zookeeper data directory
         '';
@@ -172,6 +174,7 @@ in
       zkLogDir = mkOption {
         type = types.path;
         default = "${cfg.baseDir}/zkLogs";
+        defaultText = literalExpression ''"''${config.${opt.baseDir}}/zkLogs"'';
         description = ''
           The Zookeeper logs directory
         '';
diff --git a/nixos/modules/services/misc/gitea.nix b/nixos/modules/services/misc/gitea.nix
index c0f7661c569..938bb28da90 100644
--- a/nixos/modules/services/misc/gitea.nix
+++ b/nixos/modules/services/misc/gitea.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.gitea;
+  opt = options.services.gitea;
   gitea = cfg.package;
   pg = config.services.postgresql;
   useMysql = cfg.database.type == "mysql";
@@ -51,6 +52,7 @@ in
       log = {
         rootPath = mkOption {
           default = "${cfg.stateDir}/log";
+          defaultText = literalExpression ''"''${config.${opt.stateDir}}/log"'';
           type = types.str;
           description = "Root path for log files.";
         };
@@ -130,6 +132,7 @@ in
         path = mkOption {
           type = types.str;
           default = "${cfg.stateDir}/data/gitea.db";
+          defaultText = literalExpression ''"''${config.${opt.stateDir}}/data/gitea.db"'';
           description = "Path to the sqlite3 database file.";
         };
 
@@ -166,6 +169,7 @@ in
         backupDir = mkOption {
           type = types.str;
           default = "${cfg.stateDir}/dump";
+          defaultText = literalExpression ''"''${config.${opt.stateDir}}/dump"'';
           description = "Path to the dump files.";
         };
       };
@@ -199,6 +203,7 @@ in
         contentDir = mkOption {
           type = types.str;
           default = "${cfg.stateDir}/data/lfs";
+          defaultText = literalExpression ''"''${config.${opt.stateDir}}/data/lfs"'';
           description = "Where to store LFS files.";
         };
       };
@@ -212,6 +217,7 @@ in
       repositoryRoot = mkOption {
         type = types.str;
         default = "${cfg.stateDir}/repositories";
+        defaultText = literalExpression ''"''${config.${opt.stateDir}}/repositories"'';
         description = "Path to the git repositories.";
       };
 
diff --git a/nixos/modules/services/misc/gogs.nix b/nixos/modules/services/misc/gogs.nix
index d7233f10c7c..c7ae4f49407 100644
--- a/nixos/modules/services/misc/gogs.nix
+++ b/nixos/modules/services/misc/gogs.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.gogs;
+  opt = options.services.gogs;
   configFile = pkgs.writeText "app.ini" ''
     APP_NAME = ${cfg.appName}
     RUN_USER = ${cfg.user}
@@ -129,6 +130,7 @@ in
         path = mkOption {
           type = types.str;
           default = "${cfg.stateDir}/data/gogs.db";
+          defaultText = literalExpression ''"''${config.${opt.stateDir}}/data/gogs.db"'';
           description = "Path to the sqlite3 database file.";
         };
       };
@@ -142,6 +144,7 @@ in
       repositoryRoot = mkOption {
         type = types.str;
         default = "${cfg.stateDir}/repositories";
+        defaultText = literalExpression ''"''${config.${opt.stateDir}}/repositories"'';
         description = "Path to the git repositories.";
       };
 
diff --git a/nixos/modules/services/misc/headphones.nix b/nixos/modules/services/misc/headphones.nix
index 3ee0a4458bd..31bd61cb4c2 100644
--- a/nixos/modules/services/misc/headphones.nix
+++ b/nixos/modules/services/misc/headphones.nix
@@ -1,4 +1,4 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
@@ -7,6 +7,7 @@ let
   name = "headphones";
 
   cfg = config.services.headphones;
+  opt = options.services.headphones;
 
 in
 
@@ -29,6 +30,7 @@ in
       configFile = mkOption {
         type = types.path;
         default = "${cfg.dataDir}/config.ini";
+        defaultText = literalExpression ''"''${config.${opt.dataDir}}/config.ini"'';
         description = "Path to config file.";
       };
       host = mkOption {
diff --git a/nixos/modules/services/misc/matrix-appservice-discord.nix b/nixos/modules/services/misc/matrix-appservice-discord.nix
index c448614eca3..84c4a5443fa 100644
--- a/nixos/modules/services/misc/matrix-appservice-discord.nix
+++ b/nixos/modules/services/misc/matrix-appservice-discord.nix
@@ -1,4 +1,4 @@
-{ config, pkgs, lib, ... }:
+{ config, options, pkgs, lib, ... }:
 
 with lib;
 
@@ -7,6 +7,7 @@ let
   registrationFile = "${dataDir}/discord-registration.yaml";
   appDir = "${pkgs.matrix-appservice-discord}/${pkgs.matrix-appservice-discord.passthru.nodeAppDir}";
   cfg = config.services.matrix-appservice-discord;
+  opt = options.services.matrix-appservice-discord;
   # TODO: switch to configGen.json once RFC42 is implemented
   settingsFile = pkgs.writeText "matrix-appservice-discord-settings.json" (builtins.toJSON cfg.settings);
 
@@ -74,6 +75,7 @@ in {
       url = mkOption {
         type = types.str;
         default = "http://localhost:${toString cfg.port}";
+        defaultText = literalExpression ''"http://localhost:''${toString config.${opt.port}}"'';
         description = ''
           The URL where the application service is listening for HS requests.
         '';
diff --git a/nixos/modules/services/misc/mwlib.nix b/nixos/modules/services/misc/mwlib.nix
index ec8ecee8423..fedc1e5542a 100644
--- a/nixos/modules/services/misc/mwlib.nix
+++ b/nixos/modules/services/misc/mwlib.nix
@@ -47,6 +47,9 @@ in
 
       qserve = mkOption {
         default = [ "${cfg.qserve.address}:${toString cfg.qserve.port}" ];
+        defaultText = literalExpression ''
+          [ "''${config.${opt.qserve.address}}:''${toString config.${opt.qserve.port}}"
+        ]'';
         type = types.listOf types.str;
         description = "Register qserve instance.";
       }; # nserve.qserve
@@ -129,7 +132,7 @@ in
           You have to enable it, or use your own way for serving files
           and set the http.url option accordingly.
           '';
-        type = types.submodule ({
+        type = types.submodule ({ config, options, ... }: {
           options = {
             enable = mkOption {
               default = true;
@@ -150,7 +153,8 @@ in
             }; # nslave.http.address
 
             url = mkOption {
-              default = "http://localhost:${toString cfg.nslave.http.port}/cache";
+              default = "http://localhost:${toString config.port}/cache";
+              defaultText = literalExpression ''"http://localhost:''${toString config.${options.port}}/cache"'';
               type = types.str;
               description = ''
                 Specify URL for accessing generated files from cache.
diff --git a/nixos/modules/services/misc/sickbeard.nix b/nixos/modules/services/misc/sickbeard.nix
index 8e871309c98..a3db9928634 100644
--- a/nixos/modules/services/misc/sickbeard.nix
+++ b/nixos/modules/services/misc/sickbeard.nix
@@ -1,4 +1,4 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
@@ -7,6 +7,7 @@ let
   name = "sickbeard";
 
   cfg = config.services.sickbeard;
+  opt = options.services.sickbeard;
   sickbeard = cfg.package;
 
 in
@@ -39,6 +40,7 @@ in
       configFile = mkOption {
         type = types.path;
         default = "${cfg.dataDir}/config.ini";
+        defaultText = literalExpression ''"''${config.${opt.dataDir}}/config.ini"'';
         description = "Path to config file.";
       };
       port = mkOption {
diff --git a/nixos/modules/services/misc/sourcehut/builds.nix b/nixos/modules/services/misc/sourcehut/builds.nix
index f806e8c51b9..2872606e78f 100644
--- a/nixos/modules/services/misc/sourcehut/builds.nix
+++ b/nixos/modules/services/misc/sourcehut/builds.nix
@@ -1,8 +1,9 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 let
   cfg = config.services.sourcehut;
+  opt = options.services.sourcehut;
   scfg = cfg.builds;
   rcfg = config.services.redis;
   iniKey = "builds.sr.ht";
@@ -38,6 +39,7 @@ in
     statePath = mkOption {
       type = types.path;
       default = "${cfg.statePath}/buildsrht";
+      defaultText = literalExpression ''"''${config.${opt.statePath}}/buildsrht"'';
       description = ''
         State path for builds.sr.ht.
       '';
diff --git a/nixos/modules/services/misc/sourcehut/dispatch.nix b/nixos/modules/services/misc/sourcehut/dispatch.nix
index a9db17bebe8..292a51d3e1c 100644
--- a/nixos/modules/services/misc/sourcehut/dispatch.nix
+++ b/nixos/modules/services/misc/sourcehut/dispatch.nix
@@ -1,8 +1,9 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 let
   cfg = config.services.sourcehut;
+  opt = options.services.sourcehut;
   cfgIni = cfg.settings;
   scfg = cfg.dispatch;
   iniKey = "dispatch.sr.ht";
@@ -38,6 +39,7 @@ in
     statePath = mkOption {
       type = types.path;
       default = "${cfg.statePath}/dispatchsrht";
+      defaultText = literalExpression ''"''${config.${opt.statePath}}/dispatchsrht"'';
       description = ''
         State path for dispatch.sr.ht.
       '';
diff --git a/nixos/modules/services/misc/sourcehut/git.nix b/nixos/modules/services/misc/sourcehut/git.nix
index 2653d77876d..5ce16df8cd8 100644
--- a/nixos/modules/services/misc/sourcehut/git.nix
+++ b/nixos/modules/services/misc/sourcehut/git.nix
@@ -1,8 +1,9 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 let
   cfg = config.services.sourcehut;
+  opt = options.services.sourcehut;
   scfg = cfg.git;
   iniKey = "git.sr.ht";
 
@@ -41,6 +42,7 @@ in
     statePath = mkOption {
       type = types.path;
       default = "${cfg.statePath}/gitsrht";
+      defaultText = literalExpression ''"''${config.${opt.statePath}}/gitsrht"'';
       description = ''
         State path for git.sr.ht.
       '';
diff --git a/nixos/modules/services/misc/sourcehut/hg.nix b/nixos/modules/services/misc/sourcehut/hg.nix
index 5cd36bb0455..6ba1df8b6dd 100644
--- a/nixos/modules/services/misc/sourcehut/hg.nix
+++ b/nixos/modules/services/misc/sourcehut/hg.nix
@@ -1,8 +1,9 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 let
   cfg = config.services.sourcehut;
+  opt = options.services.sourcehut;
   scfg = cfg.hg;
   iniKey = "hg.sr.ht";
 
@@ -40,6 +41,7 @@ in
     statePath = mkOption {
       type = types.path;
       default = "${cfg.statePath}/hgsrht";
+      defaultText = literalExpression ''"''${config.${opt.statePath}}/hgsrht"'';
       description = ''
         State path for hg.sr.ht.
       '';
diff --git a/nixos/modules/services/misc/sourcehut/hub.nix b/nixos/modules/services/misc/sourcehut/hub.nix
index be3ea21011c..7d137a76505 100644
--- a/nixos/modules/services/misc/sourcehut/hub.nix
+++ b/nixos/modules/services/misc/sourcehut/hub.nix
@@ -1,8 +1,9 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 let
   cfg = config.services.sourcehut;
+  opt = options.services.sourcehut;
   cfgIni = cfg.settings;
   scfg = cfg.hub;
   iniKey = "hub.sr.ht";
@@ -38,6 +39,7 @@ in
     statePath = mkOption {
       type = types.path;
       default = "${cfg.statePath}/hubsrht";
+      defaultText = literalExpression ''"''${config.${opt.statePath}}/hubsrht"'';
       description = ''
         State path for hub.sr.ht.
       '';
diff --git a/nixos/modules/services/misc/sourcehut/lists.nix b/nixos/modules/services/misc/sourcehut/lists.nix
index 7b1fe9fd463..76f155caa05 100644
--- a/nixos/modules/services/misc/sourcehut/lists.nix
+++ b/nixos/modules/services/misc/sourcehut/lists.nix
@@ -1,11 +1,12 @@
 # Email setup is fairly involved, useful references:
 # https://drewdevault.com/2018/08/05/Local-mail-server.html
 
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 let
   cfg = config.services.sourcehut;
+  opt = options.services.sourcehut;
   cfgIni = cfg.settings;
   scfg = cfg.lists;
   iniKey = "lists.sr.ht";
@@ -42,6 +43,7 @@ in
     statePath = mkOption {
       type = types.path;
       default = "${cfg.statePath}/listssrht";
+      defaultText = literalExpression ''"''${config.${opt.statePath}}/listssrht"'';
       description = ''
         State path for lists.sr.ht.
       '';
diff --git a/nixos/modules/services/misc/sourcehut/man.nix b/nixos/modules/services/misc/sourcehut/man.nix
index 7693396d187..8ca271c32ee 100644
--- a/nixos/modules/services/misc/sourcehut/man.nix
+++ b/nixos/modules/services/misc/sourcehut/man.nix
@@ -1,8 +1,9 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 let
   cfg = config.services.sourcehut;
+  opt = options.services.sourcehut;
   cfgIni = cfg.settings;
   scfg = cfg.man;
   iniKey = "man.sr.ht";
@@ -38,6 +39,7 @@ in
     statePath = mkOption {
       type = types.path;
       default = "${cfg.statePath}/mansrht";
+      defaultText = literalExpression ''"''${config.${opt.statePath}}/mansrht"'';
       description = ''
         State path for man.sr.ht.
       '';
diff --git a/nixos/modules/services/misc/sourcehut/meta.nix b/nixos/modules/services/misc/sourcehut/meta.nix
index 56127a824eb..33e4f2332b5 100644
--- a/nixos/modules/services/misc/sourcehut/meta.nix
+++ b/nixos/modules/services/misc/sourcehut/meta.nix
@@ -1,8 +1,9 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 let
   cfg = config.services.sourcehut;
+  opt = options.services.sourcehut;
   cfgIni = cfg.settings;
   scfg = cfg.meta;
   iniKey = "meta.sr.ht";
@@ -39,6 +40,7 @@ in
     statePath = mkOption {
       type = types.path;
       default = "${cfg.statePath}/metasrht";
+      defaultText = literalExpression ''"''${config.${opt.statePath}}/metasrht"'';
       description = ''
         State path for meta.sr.ht.
       '';
diff --git a/nixos/modules/services/misc/sourcehut/paste.nix b/nixos/modules/services/misc/sourcehut/paste.nix
index b2d5151969e..b481ebaf891 100644
--- a/nixos/modules/services/misc/sourcehut/paste.nix
+++ b/nixos/modules/services/misc/sourcehut/paste.nix
@@ -1,8 +1,9 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 let
   cfg = config.services.sourcehut;
+  opt = options.services.sourcehut;
   cfgIni = cfg.settings;
   scfg = cfg.paste;
   iniKey = "paste.sr.ht";
@@ -39,6 +40,7 @@ in
     statePath = mkOption {
       type = types.path;
       default = "${cfg.statePath}/pastesrht";
+      defaultText = literalExpression ''"''${config.${opt.statePath}}/pastesrht"'';
       description = ''
         State path for pastesrht.sr.ht.
       '';
diff --git a/nixos/modules/services/misc/sourcehut/todo.nix b/nixos/modules/services/misc/sourcehut/todo.nix
index aec773b0669..262fa48f59d 100644
--- a/nixos/modules/services/misc/sourcehut/todo.nix
+++ b/nixos/modules/services/misc/sourcehut/todo.nix
@@ -1,8 +1,9 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 let
   cfg = config.services.sourcehut;
+  opt = options.services.sourcehut;
   cfgIni = cfg.settings;
   scfg = cfg.todo;
   iniKey = "todo.sr.ht";
@@ -39,6 +40,7 @@ in
     statePath = mkOption {
       type = types.path;
       default = "${cfg.statePath}/todosrht";
+      defaultText = literalExpression ''"''${config.${opt.statePath}}/todosrht"'';
       description = ''
         State path for todo.sr.ht.
       '';
diff --git a/nixos/modules/services/monitoring/grafana.nix b/nixos/modules/services/monitoring/grafana.nix
index 5067047e969..81fca33f5fe 100644
--- a/nixos/modules/services/monitoring/grafana.nix
+++ b/nixos/modules/services/monitoring/grafana.nix
@@ -404,6 +404,7 @@ in {
       path = mkOption {
         description = "Database path.";
         default = "${cfg.dataDir}/data/grafana.db";
+        defaultText = literalExpression ''"''${config.${opt.dataDir}}/data/grafana.db"'';
         type = types.path;
       };
 
diff --git a/nixos/modules/services/monitoring/graphite.nix b/nixos/modules/services/monitoring/graphite.nix
index 4690a252c92..feb952324d4 100644
--- a/nixos/modules/services/monitoring/graphite.nix
+++ b/nixos/modules/services/monitoring/graphite.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.graphite;
+  opt = options.services.graphite;
   writeTextOrNull = f: t: mapNullable (pkgs.writeTextDir f) t;
 
   dataDir = cfg.dataDir;
@@ -312,12 +313,14 @@ in {
 
       seyrenUrl = mkOption {
         default = "http://localhost:${toString cfg.seyren.port}/";
+        defaultText = literalExpression ''"http://localhost:''${toString config.${opt.seyren.port}}/"'';
         description = "Host where seyren is accessible.";
         type = types.str;
       };
 
       graphiteUrl = mkOption {
         default = "http://${cfg.web.listenAddress}:${toString cfg.web.port}";
+        defaultText = literalExpression ''"http://''${config.${opt.web.listenAddress}}:''${toString config.${opt.web.port}}"'';
         description = "Host where graphite service runs.";
         type = types.str;
       };
diff --git a/nixos/modules/services/security/privacyidea.nix b/nixos/modules/services/security/privacyidea.nix
index 05f4995cc41..dacbffec04e 100644
--- a/nixos/modules/services/security/privacyidea.nix
+++ b/nixos/modules/services/security/privacyidea.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.privacyidea;
+  opt = options.services.privacyidea;
 
   uwsgi = pkgs.uwsgi.override { plugins = [ "python3" ]; };
   python = uwsgi.python3;
@@ -112,6 +113,7 @@ in
       encFile = mkOption {
         type = types.str;
         default = "${cfg.stateDir}/enckey";
+        defaultText = literalExpression ''"''${config.${opt.stateDir}}/enckey"'';
         description = ''
           This is used to encrypt the token data and token passwords
         '';
@@ -120,6 +122,7 @@ in
       auditKeyPrivate = mkOption {
         type = types.str;
         default = "${cfg.stateDir}/private.pem";
+        defaultText = literalExpression ''"''${config.${opt.stateDir}}/private.pem"'';
         description = ''
           Private Key for signing the audit log.
         '';
@@ -128,6 +131,7 @@ in
       auditKeyPublic = mkOption {
         type = types.str;
         default = "${cfg.stateDir}/public.pem";
+        defaultText = literalExpression ''"''${config.${opt.stateDir}}/public.pem"'';
         description = ''
           Public key for checking signatures of the audit log.
         '';
diff --git a/nixos/modules/services/torrent/peerflix.nix b/nixos/modules/services/torrent/peerflix.nix
index 3e5f80960dc..821c829f6b4 100644
--- a/nixos/modules/services/torrent/peerflix.nix
+++ b/nixos/modules/services/torrent/peerflix.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.peerflix;
+  opt = options.services.peerflix;
 
   configFile = pkgs.writeText "peerflix-config.json" ''
     {
@@ -32,6 +33,7 @@ in {
     downloadDir = mkOption {
       description = "Peerflix temporary download directory.";
       default = "${cfg.stateDir}/torrents";
+      defaultText = literalExpression ''"''${config.${opt.stateDir}}/torrents"'';
       type = types.path;
     };
   };
diff --git a/nixos/modules/services/torrent/rtorrent.nix b/nixos/modules/services/torrent/rtorrent.nix
index dd7df623c73..759dcfe2e6c 100644
--- a/nixos/modules/services/torrent/rtorrent.nix
+++ b/nixos/modules/services/torrent/rtorrent.nix
@@ -1,10 +1,11 @@
-{ config, pkgs, lib, ... }:
+{ config, options, pkgs, lib, ... }:
 
 with lib;
 
 let
 
   cfg = config.services.rtorrent;
+  opt = options.services.rtorrent;
 
 in {
   options.services.rtorrent = {
@@ -21,6 +22,7 @@ in {
     downloadDir = mkOption {
       type = types.str;
       default = "${cfg.dataDir}/download";
+      defaultText = literalExpression ''"''${config.${opt.dataDir}}/download"'';
       description = ''
         Where to put downloaded files.
       '';
diff --git a/nixos/modules/services/video/unifi-video.nix b/nixos/modules/services/video/unifi-video.nix
index 17971b23db8..43208a9fe4c 100644
--- a/nixos/modules/services/video/unifi-video.nix
+++ b/nixos/modules/services/video/unifi-video.nix
@@ -1,7 +1,8 @@
-{ config, lib, pkgs, utils, ... }:
+{ config, lib, options, pkgs, utils, ... }:
 with lib;
 let
   cfg = config.services.unifi-video;
+  opt = options.services.unifi-video;
   mainClass = "com.ubnt.airvision.Main";
   cmd = ''
     ${pkgs.jsvc}/bin/jsvc \
@@ -164,6 +165,7 @@ in
       pidFile = mkOption {
         type = types.path;
         default = "${cfg.dataDir}/unifi-video.pid";
+        defaultText = literalExpression ''"''${config.${opt.dataDir}}/unifi-video.pid"'';
         description = "Location of unifi-video pid file.";
       };
 

From ed673a69dbf5f9be67183621eb0f5c1759d48299 Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Sun, 5 Dec 2021 21:45:35 +0100
Subject: [PATCH 06/16] treewide: add defaultText for options with simple cfg.*
 expression defaults

adds defaultText for options with defaults that use only literals, full config.*
paths, and the cfg shortcut binding.
---
 .../cluster/kubernetes/addons/dashboard.nix       | 14 +++++++++++++-
 nixos/modules/services/misc/gitlab.nix            |  1 +
 nixos/modules/services/misc/moonraker.nix         |  4 +++-
 nixos/modules/services/monitoring/parsedmarc.nix  |  6 +++++-
 nixos/modules/services/monitoring/uptime.nix      | 10 +++++++---
 nixos/modules/services/networking/wireguard.nix   |  4 +++-
 .../services/networking/wpa_supplicant.nix        |  4 +++-
 nixos/modules/services/search/kibana.nix          |  6 +++++-
 nixos/modules/services/security/tor.nix           |  8 +++++++-
 nixos/modules/services/security/vault.nix         |  8 +++++++-
 .../modules/services/video/epgstation/default.nix |  1 +
 nixos/modules/services/web-apps/discourse.nix     |  1 +
 nixos/modules/services/web-apps/keycloak.nix      |  4 +++-
 nixos/modules/services/web-apps/peertube.nix      | 15 +++++++++++++++
 nixos/modules/services/web-apps/zabbix.nix        |  8 +++++++-
 .../services/x11/display-managers/default.nix     | 10 ++++++----
 nixos/modules/services/x11/picom.nix              | 14 ++++++++++++--
 nixos/modules/tasks/network-interfaces.nix        |  4 ++++
 18 files changed, 103 insertions(+), 19 deletions(-)

diff --git a/nixos/modules/services/cluster/kubernetes/addons/dashboard.nix b/nixos/modules/services/cluster/kubernetes/addons/dashboard.nix
index 2ed7742eda0..54b1f3859fc 100644
--- a/nixos/modules/services/cluster/kubernetes/addons/dashboard.nix
+++ b/nixos/modules/services/cluster/kubernetes/addons/dashboard.nix
@@ -1,9 +1,10 @@
-{ config, pkgs, lib, ... }:
+{ config, options, pkgs, lib, ... }:
 
 with lib;
 
 let
   cfg = config.services.kubernetes.addons.dashboard;
+  opt = options.services.kubernetes.addons.dashboard;
 in {
   imports = [
     (mkRenamedOptionModule [ "services" "kubernetes" "addons" "dashboard" "enableRBAC" ] [ "services" "kubernetes" "addons" "dashboard" "rbac" "enable" ])
@@ -28,6 +29,9 @@ in {
             description = "Whether to enable role based access control is enabled for kubernetes dashboard";
             type = types.bool;
             default = elem "RBAC" config.services.kubernetes.apiserver.authorizationMode;
+            defaultText = literalExpression ''
+              elem "RBAC" config.${options.services.kubernetes.apiserver.authorizationMode}
+            '';
           };
 
           clusterAdmin = mkOption {
@@ -54,6 +58,14 @@ in {
         finalImageTag = cfg.version;
         sha256 = "01xrr4pwgr2hcjrjsi3d14ifpzdfbxzqpzxbk2fkbjb9zkv38zxy";
       };
+      defaultText = literalExpression ''
+        {
+          imageName = "k8s.gcr.io/kubernetes-dashboard-amd64";
+          imageDigest = "sha256:0ae6b69432e78069c5ce2bcde0fe409c5c4d6f0f4d9cd50a17974fea38898747";
+          finalImageTag = config.${opt.version};
+          sha256 = "01xrr4pwgr2hcjrjsi3d14ifpzdfbxzqpzxbk2fkbjb9zkv38zxy";
+        };
+      '';
     };
   };
 
diff --git a/nixos/modules/services/misc/gitlab.nix b/nixos/modules/services/misc/gitlab.nix
index cc924163ef0..b04ef29d93d 100644
--- a/nixos/modules/services/misc/gitlab.nix
+++ b/nixos/modules/services/misc/gitlab.nix
@@ -310,6 +310,7 @@ in {
       backup.path = mkOption {
         type = types.str;
         default = cfg.statePath + "/backup";
+        defaultText = literalExpression ''config.${opt.statePath} + "/backup"'';
         description = "GitLab path for backups.";
       };
 
diff --git a/nixos/modules/services/misc/moonraker.nix b/nixos/modules/services/misc/moonraker.nix
index de8668a0c06..14e767abb25 100644
--- a/nixos/modules/services/misc/moonraker.nix
+++ b/nixos/modules/services/misc/moonraker.nix
@@ -1,8 +1,9 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 with lib;
 let
   pkg = pkgs.moonraker;
   cfg = config.services.moonraker;
+  opt = options.services.moonraker;
   format = pkgs.formats.ini {
     # https://github.com/NixOS/nixpkgs/pull/121613#issuecomment-885241996
     listToValue = l:
@@ -30,6 +31,7 @@ in {
       configDir = mkOption {
         type = types.path;
         default = cfg.stateDir + "/config";
+        defaultText = literalExpression ''config.${opt.stateDir} + "/config"'';
         description = ''
           The directory containing client-writable configuration files.
 
diff --git a/nixos/modules/services/monitoring/parsedmarc.nix b/nixos/modules/services/monitoring/parsedmarc.nix
index eeee04b4400..3bf267bdf29 100644
--- a/nixos/modules/services/monitoring/parsedmarc.nix
+++ b/nixos/modules/services/monitoring/parsedmarc.nix
@@ -1,7 +1,8 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 let
   cfg = config.services.parsedmarc;
+  opt = options.services.parsedmarc;
   ini = pkgs.formats.ini {};
 in
 {
@@ -80,6 +81,9 @@ in
         datasource = lib.mkOption {
           type = lib.types.bool;
           default = cfg.provision.elasticsearch && config.services.grafana.enable;
+          defaultText = lib.literalExpression ''
+            config.${opt.provision.elasticsearch} && config.${options.services.grafana.enable}
+          '';
           apply = x: x && cfg.provision.elasticsearch;
           description = ''
             Whether the automatically provisioned Elasticsearch
diff --git a/nixos/modules/services/monitoring/uptime.nix b/nixos/modules/services/monitoring/uptime.nix
index 245badc3e44..79b86be6cc7 100644
--- a/nixos/modules/services/monitoring/uptime.nix
+++ b/nixos/modules/services/monitoring/uptime.nix
@@ -1,8 +1,9 @@
-{ config, pkgs, lib, ... }:
+{ config, options, pkgs, lib, ... }:
 let
-  inherit (lib) mkOption mkEnableOption mkIf mkMerge types optional;
+  inherit (lib) literalExpression mkOption mkEnableOption mkIf mkMerge types optional;
 
   cfg = config.services.uptime;
+  opt = options.services.uptime;
 
   configDir = pkgs.runCommand "config" { preferLocalBuild = true; }
   (if cfg.configFile != null then ''
@@ -52,7 +53,10 @@ in {
 
     enableWebService = mkEnableOption "the uptime monitoring program web service";
 
-    enableSeparateMonitoringService = mkEnableOption "the uptime monitoring service" // { default = cfg.enableWebService; };
+    enableSeparateMonitoringService = mkEnableOption "the uptime monitoring service" // {
+      default = cfg.enableWebService;
+      defaultText = literalExpression "config.${opt.enableWebService}";
+    };
 
     nodeEnv = mkOption {
       description = "The node environment to run in (development, production, etc.)";
diff --git a/nixos/modules/services/networking/wireguard.nix b/nixos/modules/services/networking/wireguard.nix
index 55b84935b6c..7cd44b2f8a0 100644
--- a/nixos/modules/services/networking/wireguard.nix
+++ b/nixos/modules/services/networking/wireguard.nix
@@ -1,10 +1,11 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
 
   cfg = config.networking.wireguard;
+  opt = options.networking.wireguard;
 
   kernel = config.boot.kernelPackages;
 
@@ -438,6 +439,7 @@ in
         type = types.bool;
         # 2019-05-25: Backwards compatibility.
         default = cfg.interfaces != {};
+        defaultText = literalExpression "config.${opt.interfaces} != { }";
         example = true;
       };
 
diff --git a/nixos/modules/services/networking/wpa_supplicant.nix b/nixos/modules/services/networking/wpa_supplicant.nix
index 4aa350d21a2..07dec8ea718 100644
--- a/nixos/modules/services/networking/wpa_supplicant.nix
+++ b/nixos/modules/services/networking/wpa_supplicant.nix
@@ -1,4 +1,4 @@
-{ config, lib, pkgs, utils, ... }:
+{ config, lib, options, pkgs, utils, ... }:
 
 with lib;
 
@@ -8,6 +8,7 @@ let
     else pkgs.wpa_supplicant;
 
   cfg = config.networking.wireless;
+  opt = options.networking.wireless;
 
   # Content of wpa_supplicant.conf
   generatedConfig = concatStringsSep "\n" (
@@ -421,6 +422,7 @@ in {
       dbusControlled = mkOption {
         type = types.bool;
         default = lib.length cfg.interfaces < 2;
+        defaultText = literalExpression "length config.${opt.interfaces} < 2";
         description = ''
           Whether to enable the DBus control interface.
           This is only needed when using NetworkManager or connman.
diff --git a/nixos/modules/services/search/kibana.nix b/nixos/modules/services/search/kibana.nix
index 381f5156ceb..e4ab85be9ef 100644
--- a/nixos/modules/services/search/kibana.nix
+++ b/nixos/modules/services/search/kibana.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.kibana;
+  opt = options.services.kibana;
 
   ge7 = builtins.compareVersions cfg.package.version "7" >= 0;
   lt6_6 = builtins.compareVersions cfg.package.version "6.6" < 0;
@@ -130,6 +131,9 @@ in {
           This defaults to the singleton list [ca] when the <option>ca</option> option is defined.
         '';
         default = if cfg.elasticsearch.ca == null then [] else [ca];
+        defaultText = literalExpression ''
+          if config.${opt.elasticsearch.ca} == null then [ ] else [ ca ]
+        '';
         type = types.listOf types.path;
       };
 
diff --git a/nixos/modules/services/security/tor.nix b/nixos/modules/services/security/tor.nix
index c3e3248ee8a..f3ed1d160ee 100644
--- a/nixos/modules/services/security/tor.nix
+++ b/nixos/modules/services/security/tor.nix
@@ -1,10 +1,11 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with builtins;
 with lib;
 
 let
   cfg = config.services.tor;
+  opt = options.services.tor;
   stateDir = "/var/lib/tor";
   runDir = "/run/tor";
   descriptionGeneric = option: ''
@@ -799,6 +800,11 @@ in
           options.SOCKSPort = mkOption {
             description = descriptionGeneric "SOCKSPort";
             default = if cfg.settings.HiddenServiceNonAnonymousMode == true then [{port = 0;}] else [];
+            defaultText = literalExpression ''
+              if config.${opt.settings}.HiddenServiceNonAnonymousMode == true
+              then [ { port = 0; } ]
+              else [ ]
+            '';
             example = [{port = 9090;}];
             type = types.listOf (optionSOCKSPort true);
           };
diff --git a/nixos/modules/services/security/vault.nix b/nixos/modules/services/security/vault.nix
index b0ade62d97c..d48bc472cb8 100644
--- a/nixos/modules/services/security/vault.nix
+++ b/nixos/modules/services/security/vault.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.vault;
+  opt = options.services.vault;
 
   configFile = pkgs.writeText "vault.hcl" ''
     listener "tcp" {
@@ -83,6 +84,11 @@ in
       storagePath = mkOption {
         type = types.nullOr types.path;
         default = if cfg.storageBackend == "file" then "/var/lib/vault" else null;
+        defaultText = literalExpression ''
+          if config.${opt.storageBackend} == "file"
+          then "/var/lib/vault"
+          else null
+        '';
         description = "Data directory for file backend";
       };
 
diff --git a/nixos/modules/services/video/epgstation/default.nix b/nixos/modules/services/video/epgstation/default.nix
index f895a1bfed1..afaa88c15d1 100644
--- a/nixos/modules/services/video/epgstation/default.nix
+++ b/nixos/modules/services/video/epgstation/default.nix
@@ -73,6 +73,7 @@ in
     socketioPort = mkOption {
       type = types.port;
       default = cfg.port + 1;
+      defaultText = literalExpression "config.${opt.port} + 1";
       description = ''
         Socket.io port for EPGStation to listen on.
       '';
diff --git a/nixos/modules/services/web-apps/discourse.nix b/nixos/modules/services/web-apps/discourse.nix
index e128e88cfad..e72fdc053fe 100644
--- a/nixos/modules/services/web-apps/discourse.nix
+++ b/nixos/modules/services/web-apps/discourse.nix
@@ -328,6 +328,7 @@ in
         useSSL = lib.mkOption {
           type = lib.types.bool;
           default = cfg.redis.host != "localhost";
+          defaultText = lib.literalExpression ''config.${opt.redis.host} != "localhost"'';
           description = ''
             Connect to Redis with SSL.
           '';
diff --git a/nixos/modules/services/web-apps/keycloak.nix b/nixos/modules/services/web-apps/keycloak.nix
index df8c7114102..fac8e08b359 100644
--- a/nixos/modules/services/web-apps/keycloak.nix
+++ b/nixos/modules/services/web-apps/keycloak.nix
@@ -1,7 +1,8 @@
-{ config, pkgs, lib, ... }:
+{ config, options, pkgs, lib, ... }:
 
 let
   cfg = config.services.keycloak;
+  opt = options.services.keycloak;
 in
 {
   options.services.keycloak = {
@@ -147,6 +148,7 @@ in
       useSSL = lib.mkOption {
         type = lib.types.bool;
         default = cfg.database.host != "localhost";
+        defaultText = lib.literalExpression ''config.${opt.database.host} != "localhost"'';
         description = ''
           Whether the database connection should be secured by SSL /
           TLS.
diff --git a/nixos/modules/services/web-apps/peertube.nix b/nixos/modules/services/web-apps/peertube.nix
index a9473fb8178..2abfd9152f4 100644
--- a/nixos/modules/services/web-apps/peertube.nix
+++ b/nixos/modules/services/web-apps/peertube.nix
@@ -154,6 +154,11 @@ in {
       host = lib.mkOption {
         type = lib.types.str;
         default = if cfg.database.createLocally then "/run/postgresql" else null;
+        defaultText = lib.literalExpression ''
+          if config.${opt.database.createLocally}
+          then "/run/postgresql"
+          else null
+        '';
         example = "192.168.15.47";
         description = "Database host address or unix socket.";
       };
@@ -194,12 +199,22 @@ in {
       host = lib.mkOption {
         type = lib.types.nullOr lib.types.str;
         default = if cfg.redis.createLocally && !cfg.redis.enableUnixSocket then "127.0.0.1" else null;
+        defaultText = lib.literalExpression ''
+          if config.${opt.redis.createLocally} && !config.${opt.redis.enableUnixSocket}
+          then "127.0.0.1"
+          else null
+        '';
         description = "Redis host.";
       };
 
       port = lib.mkOption {
         type = lib.types.nullOr lib.types.port;
         default = if cfg.redis.createLocally && cfg.redis.enableUnixSocket then null else 6379;
+        defaultText = lib.literalExpression ''
+          if config.${opt.redis.createLocally} && config.${opt.redis.enableUnixSocket}
+          then null
+          else 6379
+        '';
         description = "Redis port.";
       };
 
diff --git a/nixos/modules/services/web-apps/zabbix.nix b/nixos/modules/services/web-apps/zabbix.nix
index ff50b95254f..538dac0d5be 100644
--- a/nixos/modules/services/web-apps/zabbix.nix
+++ b/nixos/modules/services/web-apps/zabbix.nix
@@ -1,4 +1,4 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 let
 
@@ -6,6 +6,7 @@ let
   inherit (lib) literalExpression mapAttrs optionalString versionAtLeast;
 
   cfg = config.services.zabbixWeb;
+  opt = options.services.zabbixWeb;
   fpm = config.services.phpfpm.pools.zabbix;
 
   user = "zabbix";
@@ -82,6 +83,11 @@ in
             if cfg.database.type == "mysql" then config.services.mysql.port
             else if cfg.database.type == "pgsql" then config.services.postgresql.port
             else 1521;
+          defaultText = literalExpression ''
+            if config.${opt.database.type} == "mysql" then config.${options.services.mysql.port}
+            else if config.${opt.database.type} == "pgsql" then config.${options.services.postgresql.port}
+            else 1521
+          '';
           description = "Database host port.";
         };
 
diff --git a/nixos/modules/services/x11/display-managers/default.nix b/nixos/modules/services/x11/display-managers/default.nix
index bdc46faa7fd..3adb50c678e 100644
--- a/nixos/modules/services/x11/display-managers/default.nix
+++ b/nixos/modules/services/x11/display-managers/default.nix
@@ -7,13 +7,14 @@
 # (e.g., KDE, Gnome or a plain xterm), and optionally the *window
 # manager* (e.g. kwin or twm).
 
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
 
   cfg = config.services.xserver;
+  opt = options.services.xserver;
   xorg = pkgs.xorg;
 
   fontconfig = config.fonts.fontconfig;
@@ -337,11 +338,12 @@ in
 
       # Configuration for automatic login. Common for all DM.
       autoLogin = mkOption {
-        type = types.submodule {
+        type = types.submodule ({ config, options, ... }: {
           options = {
             enable = mkOption {
               type = types.bool;
-              default = cfg.displayManager.autoLogin.user != null;
+              default = config.user != null;
+              defaultText = literalExpression "config.${options.user} != null";
               description = ''
                 Automatically log in as <option>autoLogin.user</option>.
               '';
@@ -355,7 +357,7 @@ in
               '';
             };
           };
-        };
+        });
 
         default = {};
         description = ''
diff --git a/nixos/modules/services/x11/picom.nix b/nixos/modules/services/x11/picom.nix
index dbd4b1cefef..b40e20bcd35 100644
--- a/nixos/modules/services/x11/picom.nix
+++ b/nixos/modules/services/x11/picom.nix
@@ -1,10 +1,11 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
 
   cfg = config.services.picom;
+  opt = options.services.picom;
 
   pairOf = x: with types;
     addCheck (listOf x) (y: length y == 2)
@@ -178,7 +179,16 @@ in {
 
     wintypes = mkOption {
       type = types.attrs;
-      default = { popup_menu = { opacity = cfg.menuOpacity; }; dropdown_menu = { opacity = cfg.menuOpacity; }; };
+      default = {
+        popup_menu = { opacity = cfg.menuOpacity; };
+        dropdown_menu = { opacity = cfg.menuOpacity; };
+      };
+      defaultText = literalExpression ''
+        {
+          popup_menu = { opacity = config.${opt.menuOpacity}; };
+          dropdown_menu = { opacity = config.${opt.menuOpacity}; };
+        }
+      '';
       example = {};
       description = ''
         Rules for specific window types.
diff --git a/nixos/modules/tasks/network-interfaces.nix b/nixos/modules/tasks/network-interfaces.nix
index 49901cda848..3d1fa793eb3 100644
--- a/nixos/modules/tasks/network-interfaces.nix
+++ b/nixos/modules/tasks/network-interfaces.nix
@@ -6,6 +6,7 @@ with utils;
 let
 
   cfg = config.networking;
+  opt = options.networking;
   interfaces = attrValues cfg.interfaces;
   hasVirtuals = any (i: i.virtual) interfaces;
   hasSits = cfg.sits != { };
@@ -1169,6 +1170,9 @@ in
 
     networking.tempAddresses = mkOption {
       default = if cfg.enableIPv6 then "default" else "disabled";
+      defaultText = literalExpression ''
+        if ''${config.${opt.enableIPv6}} then "default" else "disabled"
+      '';
       type = types.enum (lib.attrNames tempaddrValues);
       description = ''
         Whether to enable IPv6 Privacy Extensions for interfaces not

From e72435e6125f51a5f331080ed1862bdc86d36769 Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Sun, 5 Dec 2021 21:58:27 +0100
Subject: [PATCH 07/16] treewide: make option descriptions constants

escape interpolations in descriptions where possible, replace them with
sufficiently descriptive text elsewhere. also expand cfg.* paths in
descriptions.
---
 nixos/modules/services/games/terraria.nix    | 5 +++--
 nixos/modules/services/misc/airsonic.nix     | 5 +++--
 nixos/modules/services/misc/mediatomb.nix    | 6 +++---
 nixos/modules/services/misc/subsonic.nix     | 9 ++++++---
 nixos/modules/services/misc/zoneminder.nix   | 2 +-
 nixos/modules/services/networking/ntopng.nix | 7 ++++---
 nixos/modules/services/web-apps/hedgedoc.nix | 2 +-
 nixos/modules/services/web-apps/matomo.nix   | 2 +-
 8 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/nixos/modules/services/games/terraria.nix b/nixos/modules/services/games/terraria.nix
index 7312c7e6b63..29f976b3c2a 100644
--- a/nixos/modules/services/games/terraria.nix
+++ b/nixos/modules/services/games/terraria.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg   = config.services.terraria;
+  opt   = options.services.terraria;
   worldSizeMap = { small = 1; medium = 2; large = 3; };
   valFlag = name: val: optionalString (val != null) "-${name} \"${escape ["\\" "\""] (toString val)}\"";
   boolFlag = name: val: optionalString val "-${name}";
@@ -36,7 +37,7 @@ in
         type        = types.bool;
         default     = false;
         description = ''
-          If enabled, starts a Terraria server. The server can be connected to via <literal>tmux -S ${cfg.dataDir}/terraria.sock attach</literal>
+          If enabled, starts a Terraria server. The server can be connected to via <literal>tmux -S ''${config.${opt.dataDir}}/terraria.sock attach</literal>
           for administration by users who are a part of the <literal>terraria</literal> group (use <literal>C-b d</literal> shortcut to detach again).
         '';
       };
diff --git a/nixos/modules/services/misc/airsonic.nix b/nixos/modules/services/misc/airsonic.nix
index 533a3d367a3..5a5c30a4123 100644
--- a/nixos/modules/services/misc/airsonic.nix
+++ b/nixos/modules/services/misc/airsonic.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.airsonic;
+  opt = options.services.airsonic;
 in {
   options = {
 
@@ -78,7 +79,7 @@ in {
         description = ''
           List of paths to transcoder executables that should be accessible
           from Airsonic. Symlinks will be created to each executable inside
-          ${cfg.home}/transcoders.
+          ''${config.${opt.home}}/transcoders.
         '';
       };
 
diff --git a/nixos/modules/services/misc/mediatomb.nix b/nixos/modules/services/misc/mediatomb.nix
index 383090575b2..0227e81cfd9 100644
--- a/nixos/modules/services/misc/mediatomb.nix
+++ b/nixos/modules/services/misc/mediatomb.nix
@@ -277,13 +277,13 @@ in {
       user = mkOption {
         type = types.str;
         default = "mediatomb";
-        description = "User account under which ${name} runs.";
+        description = "User account under which the service runs.";
       };
 
       group = mkOption {
         type = types.str;
         default = "mediatomb";
-        description = "Group account under which ${name} runs.";
+        description = "Group account under which the service runs.";
       };
 
       port = mkOption {
@@ -340,7 +340,7 @@ in {
         type = types.bool;
         default = false;
         description = ''
-          Allow ${name} to create and use its own config file inside the <literal>dataDir</literal> as
+          Allow the service to create and use its own config file inside the <literal>dataDir</literal> as
           configured by <option>services.mediatomb.dataDir</option>.
           Deactivated by default, the service then runs with the configuration generated from this module.
           Otherwise, when enabled, no service configuration is generated. Gerbera/Mediatomb then starts using
diff --git a/nixos/modules/services/misc/subsonic.nix b/nixos/modules/services/misc/subsonic.nix
index 98b85918ad1..2dda8970dd3 100644
--- a/nixos/modules/services/misc/subsonic.nix
+++ b/nixos/modules/services/misc/subsonic.nix
@@ -1,8 +1,11 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
-let cfg = config.services.subsonic; in {
+let
+  cfg = config.services.subsonic;
+  opt = options.services.subsonic;
+in {
   options = {
     services.subsonic = {
       enable = mkEnableOption "Subsonic daemon";
@@ -97,7 +100,7 @@ let cfg = config.services.subsonic; in {
         description = ''
           List of paths to transcoder executables that should be accessible
           from Subsonic. Symlinks will be created to each executable inside
-          ${cfg.home}/transcoders.
+          ''${config.${opt.home}}/transcoders.
         '';
       };
     };
diff --git a/nixos/modules/services/misc/zoneminder.nix b/nixos/modules/services/misc/zoneminder.nix
index 378da7b8744..407742f72ad 100644
--- a/nixos/modules/services/misc/zoneminder.nix
+++ b/nixos/modules/services/misc/zoneminder.nix
@@ -171,7 +171,7 @@ in {
         example = "/storage/tank";
         description = ''
           ZoneMinder can generate quite a lot of data, so in case you don't want
-          to use the default ${home}, you can override the path here.
+          to use the default ${defaultDir}, you can override the path here.
         '';
       };
 
diff --git a/nixos/modules/services/networking/ntopng.nix b/nixos/modules/services/networking/ntopng.nix
index c1525711713..77a004e8ab3 100644
--- a/nixos/modules/services/networking/ntopng.nix
+++ b/nixos/modules/services/networking/ntopng.nix
@@ -1,10 +1,11 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
 
   cfg = config.services.ntopng;
+  opt = options.services.ntopng;
   redisCfg = config.services.redis;
 
   configFile = if cfg.configText != "" then
@@ -35,8 +36,8 @@ in
           collection tool.
 
           With the default configuration, ntopng monitors all network
-          interfaces and displays its findings at http://localhost:${toString
-          cfg.http-port}. Default username and password is admin/admin.
+          interfaces and displays its findings at http://localhost:''${toString
+          config.${opt.http-port}}. Default username and password is admin/admin.
 
           See the ntopng(8) manual page and http://www.ntop.org/products/ntop/
           for more info.
diff --git a/nixos/modules/services/web-apps/hedgedoc.nix b/nixos/modules/services/web-apps/hedgedoc.nix
index e0c00fe67ea..9eeabb9d566 100644
--- a/nixos/modules/services/web-apps/hedgedoc.nix
+++ b/nixos/modules/services/web-apps/hedgedoc.nix
@@ -33,7 +33,7 @@ in
       type = types.listOf types.str;
       default = [];
       description = ''
-        Groups to which the user ${name} should be added.
+        Groups to which the service user should be added.
       '';
     };
 
diff --git a/nixos/modules/services/web-apps/matomo.nix b/nixos/modules/services/web-apps/matomo.nix
index eba55e7e9be..318c4473b55 100644
--- a/nixos/modules/services/web-apps/matomo.nix
+++ b/nixos/modules/services/web-apps/matomo.nix
@@ -83,7 +83,7 @@ in {
         default = "${user}.${fqdn}";
         example = "matomo.yourdomain.org";
         description = ''
-          URL of the host, without https prefix. By default, this is ${user}.${fqdn}, but you may want to change it if you
+          URL of the host, without https prefix. You may want to change it if you
           run Matomo on a different URL than matomo.yourdomain.
         '';
       };

From b9950385e574b9b13ddc31bd34695d6532aa4e64 Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Sun, 5 Dec 2021 22:01:03 +0100
Subject: [PATCH 08/16] treewide: make option examples constant

escape interpolations in examples, or replace them where they are not
useful.
---
 nixos/modules/services/mail/rspamd.nix              | 5 +++--
 nixos/modules/services/misc/matrix-synapse.nix      | 9 +++++----
 nixos/modules/services/misc/sourcehut/builds.nix    | 2 +-
 nixos/modules/services/networking/jibri/default.nix | 2 +-
 4 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/nixos/modules/services/mail/rspamd.nix b/nixos/modules/services/mail/rspamd.nix
index 50208cbeb00..a570e137a55 100644
--- a/nixos/modules/services/mail/rspamd.nix
+++ b/nixos/modules/services/mail/rspamd.nix
@@ -5,6 +5,7 @@ with lib;
 let
 
   cfg = config.services.rspamd;
+  opt = options.services.rspamd;
   postfixCfg = config.services.postfix;
 
   bindSocketOpts = {options, config, ... }: {
@@ -285,8 +286,8 @@ in
               bindSockets = [{
                 socket = "/run/rspamd/rspamd.sock";
                 mode = "0660";
-                owner = "${cfg.user}";
-                group = "${cfg.group}";
+                owner = "''${config.${opt.user}}";
+                group = "''${config.${opt.group}}";
               }];
             };
             controller = {
diff --git a/nixos/modules/services/misc/matrix-synapse.nix b/nixos/modules/services/misc/matrix-synapse.nix
index 950c72c6e58..90e2dbfafa1 100644
--- a/nixos/modules/services/misc/matrix-synapse.nix
+++ b/nixos/modules/services/misc/matrix-synapse.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.matrix-synapse;
+  opt = options.services.matrix-synapse;
   pg = config.services.postgresql;
   usePostgresql = cfg.database_type == "psycopg2";
   logConfigFile = pkgs.writeText "log_config.yaml" cfg.logConfig;
@@ -197,7 +198,7 @@ in {
       tls_certificate_path = mkOption {
         type = types.nullOr types.str;
         default = null;
-        example = "${cfg.dataDir}/homeserver.tls.crt";
+        example = "/var/lib/matrix-synapse/homeserver.tls.crt";
         description = ''
           PEM encoded X509 certificate for TLS.
           You can replace the self-signed certificate that synapse
@@ -209,7 +210,7 @@ in {
       tls_private_key_path = mkOption {
         type = types.nullOr types.str;
         default = null;
-        example = "${cfg.dataDir}/homeserver.tls.key";
+        example = "/var/lib/matrix-synapse/homeserver.tls.key";
         description = ''
           PEM encoded private key for TLS. Specify null if synapse is not
           speaking TLS directly.
@@ -218,7 +219,7 @@ in {
       tls_dh_params_path = mkOption {
         type = types.nullOr types.str;
         default = null;
-        example = "${cfg.dataDir}/homeserver.tls.dh";
+        example = "/var/lib/matrix-synapse/homeserver.tls.dh";
         description = ''
           PEM dh parameters for ephemeral keys
         '';
diff --git a/nixos/modules/services/misc/sourcehut/builds.nix b/nixos/modules/services/misc/sourcehut/builds.nix
index 2872606e78f..685a132d350 100644
--- a/nixos/modules/services/misc/sourcehut/builds.nix
+++ b/nixos/modules/services/misc/sourcehut/builds.nix
@@ -63,7 +63,7 @@ in
               rev = "ff96a0fa5635770390b184ae74debea75c3fd534";
               ref = "nixos-unstable";
           };
-          image_from_nixpkgs = pkgs_unstable: (import ("${pkgs.sourcehut.buildsrht}/lib/images/nixos/image.nix") {
+          image_from_nixpkgs = pkgs_unstable: (import ("''${pkgs.sourcehut.buildsrht}/lib/images/nixos/image.nix") {
             pkgs = (import pkgs_unstable {});
           });
         in
diff --git a/nixos/modules/services/networking/jibri/default.nix b/nixos/modules/services/networking/jibri/default.nix
index 96832b0eb55..113a7aa4384 100644
--- a/nixos/modules/services/networking/jibri/default.nix
+++ b/nixos/modules/services/networking/jibri/default.nix
@@ -132,7 +132,7 @@ in
         pkgs.writeScript "finalize_recording.sh" ''''''
         #!/bin/sh
         RECORDINGS_DIR=$1
-        ${pkgs.rclone}/bin/rclone copy $RECORDINGS_DIR RCLONE_REMOTE:jibri-recordings/ -v --log-file=/var/log/jitsi/jibri/recording-upload.txt
+        ''${pkgs.rclone}/bin/rclone copy $RECORDINGS_DIR RCLONE_REMOTE:jibri-recordings/ -v --log-file=/var/log/jitsi/jibri/recording-upload.txt
         exit 0
         '''''';
       '';

From 6eaf4f90c2b25918109fb2689d56e33a4f59f37d Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Sun, 5 Dec 2021 22:03:03 +0100
Subject: [PATCH 09/16] nixos/mpdscribble: add defaultText for some options
 using mpdCfg

---
 nixos/modules/services/audio/mpdscribble.nix | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/nixos/modules/services/audio/mpdscribble.nix b/nixos/modules/services/audio/mpdscribble.nix
index 1368543ae1a..57d3ef77b34 100644
--- a/nixos/modules/services/audio/mpdscribble.nix
+++ b/nixos/modules/services/audio/mpdscribble.nix
@@ -1,10 +1,11 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.mpdscribble;
   mpdCfg = config.services.mpd;
+  mpdOpt = options.services.mpd;
 
   endpointUrls = {
     "last.fm" = "http://post.audioscrobbler.com";
@@ -108,6 +109,11 @@ in {
         mpdCfg.network.listenAddress
       else
         "localhost");
+      defaultText = literalExpression ''
+        if config.${mpdOpt.network.listenAddress} != "any"
+        then config.${mpdOpt.network.listenAddress}
+        else "localhost"
+      '';
       type = types.str;
       description = ''
         Host for the mpdscribble daemon to search for a mpd daemon on.
@@ -132,6 +138,7 @@ in {
 
     port = mkOption {
       default = mpdCfg.network.port;
+      defaultText = literalExpression "config.${mpdOpt.network.port}";
       type = types.port;
       description = ''
         Port for the mpdscribble daemon to search for a mpd daemon on.

From 2d564521c094b17e88707ac95cb4b6331b1b709a Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Sun, 5 Dec 2021 22:06:49 +0100
Subject: [PATCH 10/16] treewide: add literalDocBook text to options with
 complex defaults

some options have default that are best described in prose, such as
defaults that depend on the system stateVersion, defaults that are
derivations specific to the surrounding context, or those where the
expression is much longer and harder to understand than a simple text
snippet.
---
 nixos/modules/programs/gnupg.nix              |  1 +
 nixos/modules/services/audio/mpdscribble.nix  |  4 ++++
 .../cluster/kubernetes/addons/dns.nix         |  6 ++++-
 .../services/cluster/kubernetes/kubelet.nix   |  1 +
 .../services/computing/slurm/slurm.nix        |  4 ++++
 .../modules/services/games/quake3-server.nix  |  1 +
 nixos/modules/services/misc/gitweb.nix        |  1 +
 .../modules/services/misc/matrix-synapse.nix  | 23 ++++++++++++++++++
 nixos/modules/services/misc/rippled.nix       |  1 +
 nixos/modules/services/monitoring/thanos.nix  |  3 +++
 .../modules/services/networking/firewall.nix  |  1 +
 .../modules/services/networking/syncthing.nix | 24 +++++++++++++++++--
 nixos/modules/services/web-apps/keycloak.nix  |  1 +
 nixos/modules/services/web-apps/nextcloud.nix |  1 +
 .../web-servers/lighttpd/collectd.nix         |  6 ++++-
 .../services/x11/display-managers/default.nix |  3 +++
 .../system/activation/activation-script.nix   |  1 +
 nixos/modules/system/boot/plymouth.nix        |  8 ++++++-
 nixos/modules/tasks/filesystems/zfs.nix       |  1 +
 nixos/modules/virtualisation/cri-o.nix        |  4 ++++
 20 files changed, 90 insertions(+), 5 deletions(-)

diff --git a/nixos/modules/programs/gnupg.nix b/nixos/modules/programs/gnupg.nix
index 06f49182e4d..fe5d7bd834b 100644
--- a/nixos/modules/programs/gnupg.nix
+++ b/nixos/modules/programs/gnupg.nix
@@ -71,6 +71,7 @@ in
       type = types.nullOr (types.enum pkgs.pinentry.flavors);
       example = "gnome3";
       default = defaultPinentryFlavor;
+      defaultText = literalDocBook ''matching the configured desktop environment'';
       description = ''
         Which pinentry interface to use. If not null, the path to the
         pinentry binary will be passed to gpg-agent via commandline and
diff --git a/nixos/modules/services/audio/mpdscribble.nix b/nixos/modules/services/audio/mpdscribble.nix
index 57d3ef77b34..333ffb70941 100644
--- a/nixos/modules/services/audio/mpdscribble.nix
+++ b/nixos/modules/services/audio/mpdscribble.nix
@@ -128,6 +128,10 @@ in {
           mpdCfg.credentials).passwordFile
       else
         null;
+      defaultText = literalDocBook ''
+        The first password file with read access configured for MPD when using a local instance,
+        otherwise <literal>null</literal>.
+      '';
       type = types.nullOr types.str;
       description = ''
         File containing the password for the mpd daemon.
diff --git a/nixos/modules/services/cluster/kubernetes/addons/dns.nix b/nixos/modules/services/cluster/kubernetes/addons/dns.nix
index 34943fddd3d..10f45db7883 100644
--- a/nixos/modules/services/cluster/kubernetes/addons/dns.nix
+++ b/nixos/modules/services/cluster/kubernetes/addons/dns.nix
@@ -1,4 +1,4 @@
-{ config, pkgs, lib, ... }:
+{ config, options, pkgs, lib, ... }:
 
 with lib;
 
@@ -23,6 +23,10 @@ in {
           take 3 (splitString "." config.services.kubernetes.apiserver.serviceClusterIpRange
         ))
       ) + ".254";
+      defaultText = literalDocBook ''
+        The <literal>x.y.z.254</literal> IP of
+        <literal>config.${options.services.kubernetes.apiserver.serviceClusterIpRange}</literal>.
+      '';
       type = types.str;
     };
 
diff --git a/nixos/modules/services/cluster/kubernetes/kubelet.nix b/nixos/modules/services/cluster/kubernetes/kubelet.nix
index 4c00e162efa..3a15984c230 100644
--- a/nixos/modules/services/cluster/kubernetes/kubelet.nix
+++ b/nixos/modules/services/cluster/kubernetes/kubelet.nix
@@ -36,6 +36,7 @@ let
       key = mkOption {
         description = "Key of taint.";
         default = name;
+        defaultText = literalDocBook "Name of this submodule.";
         type = str;
       };
       value = mkOption {
diff --git a/nixos/modules/services/computing/slurm/slurm.nix b/nixos/modules/services/computing/slurm/slurm.nix
index 02dfe2fe882..aa0be8726f0 100644
--- a/nixos/modules/services/computing/slurm/slurm.nix
+++ b/nixos/modules/services/computing/slurm/slurm.nix
@@ -281,6 +281,10 @@ in
         type = types.path;
         internal = true;
         default = etcSlurm;
+        defaultText = literalDocBook ''
+          Directory created from generated config files and
+          <literal>config.${opt.extraConfigPaths}</literal>.
+        '';
         description = ''
           Path to directory with slurm config files. This option is set by default from the
           Slurm module and is meant to make the Slurm config file available to other modules.
diff --git a/nixos/modules/services/games/quake3-server.nix b/nixos/modules/services/games/quake3-server.nix
index 1dc01260e8f..175af4a8382 100644
--- a/nixos/modules/services/games/quake3-server.nix
+++ b/nixos/modules/services/games/quake3-server.nix
@@ -71,6 +71,7 @@ in {
       baseq3 = mkOption {
         type = types.either types.package types.path;
         default = defaultBaseq3;
+        defaultText = literalDocBook "Manually downloaded Quake 3 installation directory.";
         example = "/var/lib/q3ds";
         description = ''
           Path to the baseq3 files (pak*.pk3). If this is on the nix store (type = package) all .pk3 files should be saved
diff --git a/nixos/modules/services/misc/gitweb.nix b/nixos/modules/services/misc/gitweb.nix
index 13396bf2eb0..a1180716e36 100644
--- a/nixos/modules/services/misc/gitweb.nix
+++ b/nixos/modules/services/misc/gitweb.nix
@@ -47,6 +47,7 @@ in
         $highlight_bin = "${pkgs.highlight}/bin/highlight";
         ${cfg.extraConfig}
       '';
+      defaultText = literalDocBook "generated config file";
       type = types.path;
       readOnly = true;
       internal = true;
diff --git a/nixos/modules/services/misc/matrix-synapse.nix b/nixos/modules/services/misc/matrix-synapse.nix
index 90e2dbfafa1..df9217cc527 100644
--- a/nixos/modules/services/misc/matrix-synapse.nix
+++ b/nixos/modules/services/misc/matrix-synapse.nix
@@ -403,6 +403,29 @@ in {
             database = cfg.database_name;
           };
         }.${cfg.database_type};
+        defaultText = literalDocBook ''
+          <variablelist>
+            <varlistentry>
+              <term>using sqlite3</term>
+              <listitem>
+                <programlisting>
+                  { database = "''${config.${opt.dataDir}}/homeserver.db"; }
+                </programlisting>
+              </listitem>
+            </varlistentry>
+            <varlistentry>
+              <term>using psycopg2</term>
+              <listitem>
+                <programlisting>
+                  psycopg2 = {
+                    user = config.${opt.database_user};
+                    database = config.${opt.database_name};
+                  }
+                </programlisting>
+              </listitem>
+            </varlistentry>
+          </variablelist>
+        '';
         description = ''
           Arguments to pass to the engine.
         '';
diff --git a/nixos/modules/services/misc/rippled.nix b/nixos/modules/services/misc/rippled.nix
index 67768a97bfb..f6ec0677774 100644
--- a/nixos/modules/services/misc/rippled.nix
+++ b/nixos/modules/services/misc/rippled.nix
@@ -401,6 +401,7 @@ in
       config = mkOption {
         internal = true;
         default = pkgs.writeText "rippled.conf" rippledCfg;
+        defaultText = literalDocBook "generated config file";
       };
     };
   };
diff --git a/nixos/modules/services/monitoring/thanos.nix b/nixos/modules/services/monitoring/thanos.nix
index da626788d82..9e93d8dbb0e 100644
--- a/nixos/modules/services/monitoring/thanos.nix
+++ b/nixos/modules/services/monitoring/thanos.nix
@@ -83,6 +83,9 @@ let
   mkArgumentsOption = cmd: mkOption {
     type = types.listOf types.str;
     default = argumentsOf cmd;
+    defaultText = literalDocBook ''
+      calculated from <literal>config.services.thanos.${cmd}</literal>
+    '';
     description = ''
       Arguments to the <literal>thanos ${cmd}</literal> command.
 
diff --git a/nixos/modules/services/networking/firewall.nix b/nixos/modules/services/networking/firewall.nix
index b5b46fe6042..ff023a888f2 100644
--- a/nixos/modules/services/networking/firewall.nix
+++ b/nixos/modules/services/networking/firewall.nix
@@ -421,6 +421,7 @@ in
       checkReversePath = mkOption {
         type = types.either types.bool (types.enum ["strict" "loose"]);
         default = kernelHasRPFilter;
+        defaultText = literalDocBook "<literal>true</literal> if supported by the chosen kernel";
         example = "loose";
         description =
           ''
diff --git a/nixos/modules/services/networking/syncthing.nix b/nixos/modules/services/networking/syncthing.nix
index 8c44687a382..e37e324019e 100644
--- a/nixos/modules/services/networking/syncthing.nix
+++ b/nixos/modules/services/networking/syncthing.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.syncthing;
+  opt = options.services.syncthing;
   defaultUser = "syncthing";
   defaultGroup = defaultUser;
 
@@ -431,7 +432,26 @@ in {
           The path where the settings and keys will exist.
         '';
         default = cfg.dataDir + optionalString cond "/.config/syncthing";
-        defaultText = literalExpression "dataDir${optionalString cond " + \"/.config/syncthing\""}";
+        defaultText = literalDocBook ''
+          <variablelist>
+            <varlistentry>
+              <term><literal>stateVersion >= 19.03</literal></term>
+              <listitem>
+                <programlisting>
+                  config.${opt.dataDir} + "/.config/syncthing"
+                </programlisting>
+              </listitem>
+            </varlistentry>
+            <varlistentry>
+              <term>otherwise</term>
+              <listitem>
+                <programlisting>
+                  config.${opt.dataDir}
+                </programlisting>
+              </listitem>
+            </varlistentry>
+          </variablelist>
+        '';
       };
 
       extraFlags = mkOption {
diff --git a/nixos/modules/services/web-apps/keycloak.nix b/nixos/modules/services/web-apps/keycloak.nix
index fac8e08b359..e08f6dcabd2 100644
--- a/nixos/modules/services/web-apps/keycloak.nix
+++ b/nixos/modules/services/web-apps/keycloak.nix
@@ -140,6 +140,7 @@ in
           lib.mkOption {
             type = lib.types.port;
             default = dbPorts.${cfg.database.type};
+            defaultText = lib.literalDocBook "default port of selected database";
             description = ''
               Port of the database to connect to.
             '';
diff --git a/nixos/modules/services/web-apps/nextcloud.nix b/nixos/modules/services/web-apps/nextcloud.nix
index 04ec7888950..dfc80bbbf42 100644
--- a/nixos/modules/services/web-apps/nextcloud.nix
+++ b/nixos/modules/services/web-apps/nextcloud.nix
@@ -499,6 +499,7 @@ in {
     occ = mkOption {
       type = types.package;
       default = occ;
+      defaultText = literalDocBook "generated script";
       internal = true;
       description = ''
         The nextcloud-occ program preconfigured to target this Nextcloud instance.
diff --git a/nixos/modules/services/web-servers/lighttpd/collectd.nix b/nixos/modules/services/web-servers/lighttpd/collectd.nix
index 3f262451c2c..5f091591daf 100644
--- a/nixos/modules/services/web-servers/lighttpd/collectd.nix
+++ b/nixos/modules/services/web-servers/lighttpd/collectd.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.lighttpd.collectd;
+  opt = options.services.lighttpd.collectd;
 
   collectionConf = pkgs.writeText "collection.conf" ''
     datadir: "${config.services.collectd.dataDir}"
@@ -29,6 +30,9 @@ in
     collectionCgi = mkOption {
       type = types.path;
       default = defaultCollectionCgi;
+      defaultText = literalDocBook ''
+        <literal>config.${options.services.collectd.package}</literal> configured for lighttpd
+      '';
       description = ''
         Path to collection.cgi script from (collectd sources)/contrib/collection.cgi
         This option allows to use a customized version
diff --git a/nixos/modules/services/x11/display-managers/default.nix b/nixos/modules/services/x11/display-managers/default.nix
index 3adb50c678e..58e4fe04f37 100644
--- a/nixos/modules/services/x11/display-managers/default.nix
+++ b/nixos/modules/services/x11/display-managers/default.nix
@@ -279,6 +279,9 @@ in
             defaultSessionFromLegacyOptions
           else
             null;
+        defaultText = literalDocBook ''
+          Taken from display manager settings or window manager settings, if either is set.
+        '';
         example = "gnome";
         description = ''
           Graphical session to pre-select in the session chooser (only effective for GDM, LightDM and SDDM).
diff --git a/nixos/modules/system/activation/activation-script.nix b/nixos/modules/system/activation/activation-script.nix
index 8dbfe393f10..154b6127b27 100644
--- a/nixos/modules/system/activation/activation-script.nix
+++ b/nixos/modules/system/activation/activation-script.nix
@@ -142,6 +142,7 @@ in
       readOnly = true;
       internal = true;
       default = systemActivationScript (removeAttrs config.system.activationScripts [ "script" ]) true;
+      defaultText = literalDocBook "generated activation script";
     };
 
     system.userActivationScripts = mkOption {
diff --git a/nixos/modules/system/boot/plymouth.nix b/nixos/modules/system/boot/plymouth.nix
index 4b8194d2f85..78ae8e9d20b 100644
--- a/nixos/modules/system/boot/plymouth.nix
+++ b/nixos/modules/system/boot/plymouth.nix
@@ -1,4 +1,4 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
@@ -7,6 +7,7 @@ let
   inherit (pkgs) plymouth nixos-icons;
 
   cfg = config.boot.plymouth;
+  opt = options.boot.plymouth;
 
   nixosBreezePlymouth = pkgs.plasma5Packages.breeze-plymouth.override {
     logoFile = cfg.logo;
@@ -71,6 +72,11 @@ in
 
       themePackages = mkOption {
         default = lib.optional (cfg.theme == "breeze") nixosBreezePlymouth;
+        defaultText = literalDocBook ''
+          A NixOS branded variant of the breeze theme when
+          <literal>config.${opt.theme} == "breeze"</literal>, otherwise
+          <literal>[ ]</literal>.
+        '';
         type = types.listOf types.package;
         description = ''
           Extra theme packages for plymouth.
diff --git a/nixos/modules/tasks/filesystems/zfs.nix b/nixos/modules/tasks/filesystems/zfs.nix
index 65364801c32..a9100da1aa4 100644
--- a/nixos/modules/tasks/filesystems/zfs.nix
+++ b/nixos/modules/tasks/filesystems/zfs.nix
@@ -112,6 +112,7 @@ in
         readOnly = true;
         type = types.bool;
         default = inInitrd || inSystem;
+        defaultText = literalDocBook "<literal>true</literal> if ZFS filesystem support is enabled";
         description = "True if ZFS filesystem support is enabled";
       };
 
diff --git a/nixos/modules/virtualisation/cri-o.nix b/nixos/modules/virtualisation/cri-o.nix
index 38766113f39..cf511000150 100644
--- a/nixos/modules/virtualisation/cri-o.nix
+++ b/nixos/modules/virtualisation/cri-o.nix
@@ -71,6 +71,10 @@ in
     package = mkOption {
       type = types.package;
       default = crioPackage;
+      defaultText = literalDocBook ''
+        <literal>pkgs.cri-o</literal> built with
+        <literal>config.${opt.extraPackages}</literal>.
+      '';
       internal = true;
       description = ''
         The final CRI-O package (including extra packages).

From 3226c5aded7bbe52cadf323eb45d3db83408ec6c Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Sun, 5 Dec 2021 22:32:19 +0100
Subject: [PATCH 11/16] nixos/hbase: refactor settings option

instead of keeping a defaultConfig value around, set that value as the
default of the option and explicitly use the option default instead.
this also allows us to write a defaultText that makes sense and is in
proximity to the definition of the default.
---
 nixos/modules/services/databases/hbase.nix | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/nixos/modules/services/databases/hbase.nix b/nixos/modules/services/databases/hbase.nix
index 181be2d6b0b..fe4f05eec64 100644
--- a/nixos/modules/services/databases/hbase.nix
+++ b/nixos/modules/services/databases/hbase.nix
@@ -1,14 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, options, lib, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.hbase;
-
-  defaultConfig = {
-    "hbase.rootdir" = "file://${cfg.dataDir}/hbase";
-    "hbase.zookeeper.property.dataDir" = "${cfg.dataDir}/zookeeper";
-  };
+  opt = options.services.hbase;
 
   buildProperty = configAttr:
     (builtins.concatStringsSep "\n"
@@ -23,7 +19,7 @@ let
 
   configFile = pkgs.writeText "hbase-site.xml"
     ''<configuration>
-        ${buildProperty (defaultConfig // cfg.settings)}
+        ${buildProperty (opt.settings.default // cfg.settings)}
       </configuration>
     '';
 
@@ -96,7 +92,16 @@ in {
 
       settings = mkOption {
         type = with lib.types; attrsOf (oneOf [ str int bool ]);
-        default = defaultConfig;
+        default = {
+          "hbase.rootdir" = "file://${cfg.dataDir}/hbase";
+          "hbase.zookeeper.property.dataDir" = "${cfg.dataDir}/zookeeper";
+        };
+        defaultText = literalExpression ''
+          {
+            "hbase.rootdir" = "file://''${config.${opt.dataDir}}/hbase";
+            "hbase.zookeeper.property.dataDir" = "''${config.${opt.dataDir}}/zookeeper";
+          }
+        '';
         description = ''
           configurations in hbase-site.xml, see <link xlink:href="https://github.com/apache/hbase/blob/master/hbase-server/src/test/resources/hbase-site.xml"/> for details.
         '';

From 9407761763a61a4f0551c43aa3b818d7ede1fa39 Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Sun, 5 Dec 2021 22:36:38 +0100
Subject: [PATCH 12/16] treewide: add defaultText for options using other
 shortcut bindings

---
 nixos/modules/services/backup/tarsnap.nix               | 4 +++-
 nixos/modules/services/monitoring/zabbix-proxy.nix      | 8 +++++++-
 nixos/modules/services/monitoring/zabbix-server.nix     | 8 +++++++-
 nixos/modules/services/web-apps/pgpkeyserver-lite.nix   | 5 ++++-
 nixos/modules/services/x11/display-managers/default.nix | 1 +
 nixos/modules/tasks/filesystems/zfs.nix                 | 4 +++-
 6 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/nixos/modules/services/backup/tarsnap.nix b/nixos/modules/services/backup/tarsnap.nix
index 9cce8683661..4dfd0a1dffb 100644
--- a/nixos/modules/services/backup/tarsnap.nix
+++ b/nixos/modules/services/backup/tarsnap.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, utils, ... }:
+{ config, lib, options, pkgs, utils, ... }:
 
 with lib;
 
 let
   gcfg = config.services.tarsnap;
+  opt = options.services.tarsnap;
 
   configFile = name: cfg: ''
     keyfile ${cfg.keyfile}
@@ -65,6 +66,7 @@ in
               keyfile = mkOption {
                 type = types.str;
                 default = gcfg.keyfile;
+                defaultText = literalExpression "config.${opt.keyfile}";
                 description = ''
                   Set a specific keyfile for this archive. This defaults to
                   <literal>"/root/tarsnap.key"</literal> if left unspecified.
diff --git a/nixos/modules/services/monitoring/zabbix-proxy.nix b/nixos/modules/services/monitoring/zabbix-proxy.nix
index b5009f47f17..0ebd7bcff83 100644
--- a/nixos/modules/services/monitoring/zabbix-proxy.nix
+++ b/nixos/modules/services/monitoring/zabbix-proxy.nix
@@ -1,7 +1,8 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 let
   cfg = config.services.zabbixProxy;
+  opt = options.services.zabbixProxy;
   pgsql = config.services.postgresql;
   mysql = config.services.mysql;
 
@@ -103,6 +104,11 @@ in
         port = mkOption {
           type = types.int;
           default = if cfg.database.type == "mysql" then mysql.port else pgsql.port;
+          defaultText = literalExpression ''
+            if config.${opt.database.type} == "mysql"
+            then config.${options.services.mysql.port}
+            else config.${options.services.postgresql.port}
+          '';
           description = "Database host port.";
         };
 
diff --git a/nixos/modules/services/monitoring/zabbix-server.nix b/nixos/modules/services/monitoring/zabbix-server.nix
index 0141c073da2..9f960517a81 100644
--- a/nixos/modules/services/monitoring/zabbix-server.nix
+++ b/nixos/modules/services/monitoring/zabbix-server.nix
@@ -1,7 +1,8 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 let
   cfg = config.services.zabbixServer;
+  opt = options.services.zabbixServer;
   pgsql = config.services.postgresql;
   mysql = config.services.mysql;
 
@@ -95,6 +96,11 @@ in
         port = mkOption {
           type = types.int;
           default = if cfg.database.type == "mysql" then mysql.port else pgsql.port;
+          defaultText = literalExpression ''
+            if config.${opt.database.type} == "mysql"
+            then config.${options.services.mysql.port}
+            else config.${options.services.postgresql.port}
+          '';
           description = "Database host port.";
         };
 
diff --git a/nixos/modules/services/web-apps/pgpkeyserver-lite.nix b/nixos/modules/services/web-apps/pgpkeyserver-lite.nix
index 5642627d397..faf0ce13238 100644
--- a/nixos/modules/services/web-apps/pgpkeyserver-lite.nix
+++ b/nixos/modules/services/web-apps/pgpkeyserver-lite.nix
@@ -1,4 +1,4 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
@@ -6,6 +6,7 @@ let
 
   cfg = config.services.pgpkeyserver-lite;
   sksCfg = config.services.sks;
+  sksOpt = options.services.sks;
 
   webPkg = cfg.package;
 
@@ -37,6 +38,7 @@ in
 
       hkpAddress = mkOption {
         default = builtins.head sksCfg.hkpAddress;
+        defaultText = literalExpression "head config.${sksOpt.hkpAddress}";
         type = types.str;
         description = "
           Wich ip address the sks-keyserver is listening on.
@@ -45,6 +47,7 @@ in
 
       hkpPort = mkOption {
         default = sksCfg.hkpPort;
+        defaultText = literalExpression "config.${sksOpt.hkpPort}";
         type = types.int;
         description = "
           Which port the sks-keyserver is listening on.
diff --git a/nixos/modules/services/x11/display-managers/default.nix b/nixos/modules/services/x11/display-managers/default.nix
index 58e4fe04f37..92b3af8527f 100644
--- a/nixos/modules/services/x11/display-managers/default.nix
+++ b/nixos/modules/services/x11/display-managers/default.nix
@@ -148,6 +148,7 @@ in
       xauthBin = mkOption {
         internal = true;
         default = "${xorg.xauth}/bin/xauth";
+        defaultText = literalExpression ''"''${pkgs.xorg.xauth}/bin/xauth"'';
         description = "Path to the <command>xauth</command> program used by display managers.";
       };
 
diff --git a/nixos/modules/tasks/filesystems/zfs.nix b/nixos/modules/tasks/filesystems/zfs.nix
index a9100da1aa4..3bc0dedec00 100644
--- a/nixos/modules/tasks/filesystems/zfs.nix
+++ b/nixos/modules/tasks/filesystems/zfs.nix
@@ -1,4 +1,4 @@
-{ config, lib, pkgs, utils, ... }:
+{ config, lib, options, pkgs, utils, ... }:
 #
 # TODO: zfs tunables
 
@@ -8,6 +8,7 @@ with lib;
 let
 
   cfgZfs = config.boot.zfs;
+  optZfs = options.boot.zfs;
   cfgExpandOnBoot = config.services.zfs.expandOnBoot;
   cfgSnapshots = config.services.zfs.autoSnapshot;
   cfgSnapFlags = cfgSnapshots.flags;
@@ -347,6 +348,7 @@ in
     services.zfs.zed = {
       enableMail = mkEnableOption "ZED's ability to send emails" // {
         default = cfgZfs.package.enableMail;
+        defaultText = literalExpression "config.${optZfs.package}.enableMail";
       };
 
       settings = mkOption {

From 1060fefae3a3a56cc86acda6346efb9b1d854b31 Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Sun, 5 Dec 2021 22:46:13 +0100
Subject: [PATCH 13/16] nixos/tarsnap, nixos/neo4j: defaultText for submodule
 options

unfortunately we don't have a good way to represent defaults that
reference other values of the current submodule, so we just use the
relative path of the referenced value and assume that the submodule was
declared as `rec`.
---
 nixos/modules/services/backup/tarsnap.nix  | 5 ++++-
 nixos/modules/services/databases/neo4j.nix | 3 +++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/nixos/modules/services/backup/tarsnap.nix b/nixos/modules/services/backup/tarsnap.nix
index 4dfd0a1dffb..965168d1ae7 100644
--- a/nixos/modules/services/backup/tarsnap.nix
+++ b/nixos/modules/services/backup/tarsnap.nix
@@ -60,7 +60,7 @@ in
       };
 
       archives = mkOption {
-        type = types.attrsOf (types.submodule ({ config, ... }:
+        type = types.attrsOf (types.submodule ({ config, options, ... }:
           {
             options = {
               keyfile = mkOption {
@@ -89,6 +89,9 @@ in
               cachedir = mkOption {
                 type = types.nullOr types.path;
                 default = "/var/cache/tarsnap/${utils.escapeSystemdPath config.keyfile}";
+                defaultText = literalExpression ''
+                  "/var/cache/tarsnap/''${utils.escapeSystemdPath config.${options.keyfile}}"
+                '';
                 description = ''
                   The cache allows tarsnap to identify previously stored data
                   blocks, reducing archival time and bandwidth usage.
diff --git a/nixos/modules/services/databases/neo4j.nix b/nixos/modules/services/databases/neo4j.nix
index b258d698664..8816f3b2e4b 100644
--- a/nixos/modules/services/databases/neo4j.nix
+++ b/nixos/modules/services/databases/neo4j.nix
@@ -437,6 +437,7 @@ in {
           baseDirectory = mkOption {
             type = types.path;
             default = "${cfg.directories.certificates}/${name}";
+            defaultText = literalExpression ''"''${config.${opt.directories.certificates}}/''${name}"'';
             description = ''
               The mandatory base directory for cryptographic objects of this
               policy. This path is only automatically generated when this
@@ -498,6 +499,7 @@ in {
           revokedDir = mkOption {
             type = types.path;
             default = "${config.baseDirectory}/revoked";
+            defaultText = literalExpression ''"''${config.${options.baseDirectory}}/revoked"'';
             description = ''
               Path to directory of CRLs (Certificate Revocation Lists) in
               PEM format. Must be an absolute path. The existence of this
@@ -533,6 +535,7 @@ in {
           trustedDir = mkOption {
             type = types.path;
             default = "${config.baseDirectory}/trusted";
+            defaultText = literalExpression ''"''${config.${options.baseDirectory}}/trusted"'';
             description = ''
               Path to directory of X.509 certificates in PEM format for
               trusted parties. Must be an absolute path. The existence of this

From 0eaf46a1dc961216016a886818ac2a66c14c74e6 Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Sun, 5 Dec 2021 22:51:41 +0100
Subject: [PATCH 14/16] nixos/system-path: add defaultText for defaultPackages

---
 nixos/modules/config/system-path.nix | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/nixos/modules/config/system-path.nix b/nixos/modules/config/system-path.nix
index 6ff4ec2921c..875c4c9c441 100644
--- a/nixos/modules/config/system-path.nix
+++ b/nixos/modules/config/system-path.nix
@@ -41,12 +41,17 @@ let
       pkgs.zstd
     ];
 
-    defaultPackages = map (pkg: setPrio ((pkg.meta.priority or 5) + 3) pkg)
-      [ pkgs.nano
-        pkgs.perl
-        pkgs.rsync
-        pkgs.strace
-      ];
+  defaultPackageNames =
+    [ "nano"
+      "perl"
+      "rsync"
+      "strace"
+    ];
+  defaultPackages =
+    map
+      (n: let pkg = pkgs.${n}; in setPrio ((pkg.meta.priority or 5) + 3) pkg)
+      defaultPackageNames;
+  defaultPackagesText = "[ ${concatMapStringsSep " " (n: "pkgs.${n}") defaultPackageNames } ]";
 
 in
 
@@ -73,6 +78,11 @@ in
       defaultPackages = mkOption {
         type = types.listOf types.package;
         default = defaultPackages;
+        defaultText = literalDocBook ''
+          these packages, with their <literal>meta.priority</literal> numerically increased
+          (thus lowering their installation priority):
+          <programlisting>${defaultPackagesText}</programlisting>
+        '';
         example = [];
         description = ''
           Set of default packages that aren't strictly necessary

From 1f960e7571d46bd13dd4b5865f115467e100ef7d Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Sun, 5 Dec 2021 22:52:01 +0100
Subject: [PATCH 15/16] nixos/captive-browser: add defaultText for browser

easiest way to do this is to move the default expression out and
abstract over what is substituted into it, using a dependent value for
the default and a descriptive value for defaultText
---
 nixos/modules/programs/captive-browser.nix | 26 ++++++++++++----------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/nixos/modules/programs/captive-browser.nix b/nixos/modules/programs/captive-browser.nix
index 0f5d087e8d8..dc054504ea4 100644
--- a/nixos/modules/programs/captive-browser.nix
+++ b/nixos/modules/programs/captive-browser.nix
@@ -3,6 +3,18 @@
 with lib;
 let
   cfg = config.programs.captive-browser;
+  browserDefault = chromium: concatStringsSep " " [
+    ''env XDG_CONFIG_HOME="$PREV_CONFIG_HOME"''
+    ''${chromium}/bin/chromium''
+    ''--user-data-dir=''${XDG_DATA_HOME:-$HOME/.local/share}/chromium-captive''
+    ''--proxy-server="socks5://$PROXY"''
+    ''--host-resolver-rules="MAP * ~NOTFOUND , EXCLUDE localhost"''
+    ''--no-first-run''
+    ''--new-window''
+    ''--incognito''
+    ''-no-default-browser-check''
+    ''http://cache.nixos.org/''
+  ];
 in
 {
   ###### interface
@@ -26,18 +38,8 @@ in
       # the options below are the same as in "captive-browser.toml"
       browser = mkOption {
         type = types.str;
-        default = concatStringsSep " " [
-          ''env XDG_CONFIG_HOME="$PREV_CONFIG_HOME"''
-          ''${pkgs.chromium}/bin/chromium''
-          ''--user-data-dir=''${XDG_DATA_HOME:-$HOME/.local/share}/chromium-captive''
-          ''--proxy-server="socks5://$PROXY"''
-          ''--host-resolver-rules="MAP * ~NOTFOUND , EXCLUDE localhost"''
-          ''--no-first-run''
-          ''--new-window''
-          ''--incognito''
-          ''-no-default-browser-check''
-          ''http://cache.nixos.org/''
-        ];
+        default = browserDefault pkgs.chromium;
+        defaultText = literalExpression (browserDefault "\${pkgs.chromium}");
         description = ''
           The shell (/bin/sh) command executed once the proxy starts.
           When browser exits, the proxy exits. An extra env var PROXY is available.

From e67a646a925bc3cda86101a3f3afb81db3030ef5 Mon Sep 17 00:00:00 2001
From: pennae <github@quasiparticle.net>
Date: Sun, 5 Dec 2021 22:56:22 +0100
Subject: [PATCH 16/16] treewide: add defaultText to remaining options

these are mostly options that use alias bindings, bindings to constants,
or bindings to calculated values.
---
 nixos/modules/services/misc/gitea.nix               |  5 +++++
 nixos/modules/services/misc/mediatomb.nix           |  4 +++-
 nixos/modules/services/monitoring/graphite.nix      |  7 +++++++
 nixos/modules/services/networking/amuled.nix        |  6 +++++-
 nixos/modules/services/networking/quassel.nix       |  6 +++++-
 nixos/modules/services/torrent/transmission.nix     |  4 ++++
 nixos/modules/services/video/epgstation/default.nix |  3 +++
 nixos/modules/services/web-apps/galene.nix          |  6 +++++-
 nixos/modules/services/web-apps/invidious.nix       |  1 +
 nixos/modules/services/web-apps/matomo.nix          | 12 +++++++-----
 10 files changed, 45 insertions(+), 9 deletions(-)

diff --git a/nixos/modules/services/misc/gitea.nix b/nixos/modules/services/misc/gitea.nix
index 938bb28da90..519bd8f5734 100644
--- a/nixos/modules/services/misc/gitea.nix
+++ b/nixos/modules/services/misc/gitea.nix
@@ -86,6 +86,11 @@ in
         port = mkOption {
           type = types.port;
           default = (if !usePostgresql then 3306 else pg.port);
+          defaultText = literalExpression ''
+            if config.${opt.database.type} != "postgresql"
+            then 3306
+            else config.${options.services.postgresql.port}
+          '';
           description = "Database host port.";
         };
 
diff --git a/nixos/modules/services/misc/mediatomb.nix b/nixos/modules/services/misc/mediatomb.nix
index 0227e81cfd9..ea9ffbb8677 100644
--- a/nixos/modules/services/misc/mediatomb.nix
+++ b/nixos/modules/services/misc/mediatomb.nix
@@ -1,4 +1,4 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
@@ -6,6 +6,7 @@ let
 
   gid = config.ids.gids.mediatomb;
   cfg = config.services.mediatomb;
+  opt = options.services.mediatomb;
   name = cfg.package.pname;
   pkg = cfg.package;
   optionYesNo = option: if option then "yes" else "no";
@@ -261,6 +262,7 @@ in {
       dataDir = mkOption {
         type = types.path;
         default = "/var/lib/${name}";
+        defaultText = literalExpression ''"/var/lib/''${config.${opt.package}.pname}"'';
         description = ''
           The directory where Gerbera/Mediatomb stores its state, data, etc.
         '';
diff --git a/nixos/modules/services/monitoring/graphite.nix b/nixos/modules/services/monitoring/graphite.nix
index feb952324d4..7f4f2a0205a 100644
--- a/nixos/modules/services/monitoring/graphite.nix
+++ b/nixos/modules/services/monitoring/graphite.nix
@@ -172,6 +172,13 @@ in {
             directories:
                 - ${dataDir}/whisper
         '';
+        defaultText = literalExpression ''
+          '''
+            whisper:
+              directories:
+                - ''${config.${opt.dataDir}}/whisper
+          '''
+        '';
         example = ''
           allowed_origins:
             - dashboard.example.com
diff --git a/nixos/modules/services/networking/amuled.nix b/nixos/modules/services/networking/amuled.nix
index 39320643dd5..e55ac7a6b18 100644
--- a/nixos/modules/services/networking/amuled.nix
+++ b/nixos/modules/services/networking/amuled.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.amule;
+  opt = options.services.amule;
   user = if cfg.user != null then cfg.user else "amule";
 in
 
@@ -26,6 +27,9 @@ in
       dataDir = mkOption {
         type = types.str;
         default = "/home/${user}/";
+        defaultText = literalExpression ''
+          "/home/''${config.${opt.user}}/"
+        '';
         description = ''
           The directory holding configuration, incoming and temporary files.
         '';
diff --git a/nixos/modules/services/networking/quassel.nix b/nixos/modules/services/networking/quassel.nix
index 22940ef7a13..844c9a6b8b3 100644
--- a/nixos/modules/services/networking/quassel.nix
+++ b/nixos/modules/services/networking/quassel.nix
@@ -1,9 +1,10 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 
 let
   cfg = config.services.quassel;
+  opt = options.services.quassel;
   quassel = cfg.package;
   user = if cfg.user != null then cfg.user else "quassel";
 in
@@ -63,6 +64,9 @@ in
 
       dataDir = mkOption {
         default = "/home/${user}/.config/quassel-irc.org";
+        defaultText = literalExpression ''
+          "/home/''${config.${opt.user}}/.config/quassel-irc.org"
+        '';
         type = types.str;
         description = ''
           The directory holding configuration files, the SQlite database and the SSL Cert.
diff --git a/nixos/modules/services/torrent/transmission.nix b/nixos/modules/services/torrent/transmission.nix
index a6ff467914a..b75507a3a1b 100644
--- a/nixos/modules/services/torrent/transmission.nix
+++ b/nixos/modules/services/torrent/transmission.nix
@@ -4,6 +4,7 @@ with lib;
 
 let
   cfg = config.services.transmission;
+  opt = options.services.transmission;
   inherit (config.environment) etc;
   apparmor = config.security.apparmor;
   rootDir = "/run/transmission";
@@ -47,11 +48,13 @@ in
           options.download-dir = mkOption {
             type = types.path;
             default = "${cfg.home}/${downloadsDir}";
+            defaultText = literalExpression ''"''${config.${opt.home}}/${downloadsDir}"'';
             description = "Directory where to download torrents.";
           };
           options.incomplete-dir = mkOption {
             type = types.path;
             default = "${cfg.home}/${incompleteDir}";
+            defaultText = literalExpression ''"''${config.${opt.home}}/${incompleteDir}"'';
             description = ''
               When enabled with
               services.transmission.home
@@ -147,6 +150,7 @@ in
           options.watch-dir = mkOption {
             type = types.path;
             default = "${cfg.home}/${watchDir}";
+            defaultText = literalExpression ''"''${config.${opt.home}}/${watchDir}"'';
             description = "Watch a directory for torrent files and add them to transmission.";
           };
           options.watch-dir-enabled = mkOption {
diff --git a/nixos/modules/services/video/epgstation/default.nix b/nixos/modules/services/video/epgstation/default.nix
index afaa88c15d1..db99f731b0a 100644
--- a/nixos/modules/services/video/epgstation/default.nix
+++ b/nixos/modules/services/video/epgstation/default.nix
@@ -186,6 +186,9 @@ in
         in {
           type = types.str;
           default = "http+unix://${replaceStrings ["/"] ["%2F"] sockPath}";
+          defaultText = literalExpression ''
+            "http+unix://''${replaceStrings ["/"] ["%2F"] config.${options.services.mirakurun.unixSocket}}"
+          '';
           example = "http://localhost:40772";
           description = "URL to connect to Mirakurun.";
         });
diff --git a/nixos/modules/services/web-apps/galene.nix b/nixos/modules/services/web-apps/galene.nix
index db9dfeb4749..1d0a620585b 100644
--- a/nixos/modules/services/web-apps/galene.nix
+++ b/nixos/modules/services/web-apps/galene.nix
@@ -1,8 +1,9 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 
 with lib;
 let
   cfg = config.services.galene;
+  opt = options.services.galene;
   defaultstateDir = "/var/lib/galene";
   defaultrecordingsDir = "${cfg.stateDir}/recordings";
   defaultgroupsDir = "${cfg.stateDir}/groups";
@@ -88,6 +89,7 @@ in
       recordingsDir = mkOption {
         type = types.str;
         default = defaultrecordingsDir;
+        defaultText = literalExpression ''"''${config.${opt.stateDir}}/recordings"'';
         example = "/var/lib/galene/recordings";
         description = "Recordings directory.";
       };
@@ -95,6 +97,7 @@ in
       dataDir = mkOption {
         type = types.str;
         default = defaultdataDir;
+        defaultText = literalExpression ''"''${config.${opt.stateDir}}/data"'';
         example = "/var/lib/galene/data";
         description = "Data directory.";
       };
@@ -102,6 +105,7 @@ in
       groupsDir = mkOption {
         type = types.str;
         default = defaultgroupsDir;
+        defaultText = literalExpression ''"''${config.${opt.stateDir}}/groups"'';
         example = "/var/lib/galene/groups";
         description = "Web server directory.";
       };
diff --git a/nixos/modules/services/web-apps/invidious.nix b/nixos/modules/services/web-apps/invidious.nix
index 7fb826af583..696fd7466f4 100644
--- a/nixos/modules/services/web-apps/invidious.nix
+++ b/nixos/modules/services/web-apps/invidious.nix
@@ -225,6 +225,7 @@ in
       port = lib.mkOption {
         type = types.port;
         default = options.services.postgresql.port.default;
+        defaultText = lib.literalExpression "options.services.postgresql.port.default";
         description = ''
           The port of the database Invidious should use.
 
diff --git a/nixos/modules/services/web-apps/matomo.nix b/nixos/modules/services/web-apps/matomo.nix
index 318c4473b55..8a0ca33b51f 100644
--- a/nixos/modules/services/web-apps/matomo.nix
+++ b/nixos/modules/services/web-apps/matomo.nix
@@ -1,4 +1,4 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, options, pkgs, ... }:
 with lib;
 let
   cfg = config.services.matomo;
@@ -12,10 +12,7 @@ let
   phpExecutionUnit = "phpfpm-${pool}";
   databaseService = "mysql.service";
 
-  fqdn =
-    let
-      join = hostName: domain: hostName + optionalString (domain != null) ".${domain}";
-     in join config.networking.hostName config.networking.domain;
+  fqdn = if config.networking.domain != null then config.networking.fqdn else config.networking.hostName;
 
 in {
   imports = [
@@ -81,6 +78,11 @@ in {
       hostname = mkOption {
         type = types.str;
         default = "${user}.${fqdn}";
+        defaultText = literalExpression ''
+          if config.${options.networking.domain} != null
+          then "${user}.''${config.${options.networking.fqdn}}"
+          else "${user}.''${config.${options.networking.hostName}}"
+        '';
         example = "matomo.yourdomain.org";
         description = ''
           URL of the host, without https prefix. You may want to change it if you