nixos/tinc: Add daemon configuration

nixos/modules/module-list.nix

@@ -293,6 +293,7 @@
   ./services/networking/syncthing.nix
   ./services/networking/tcpcrypt.nix
   ./services/networking/teamspeak3.nix
+  ./services/networking/tinc.nix
   ./services/networking/tftpd.nix
   ./services/networking/tlsdated.nix
   ./services/networking/tox-bootstrapd.nix

nixos/modules/services/networking/tinc.nix

@@ -0,0 +1,154 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  cfg = config.services.tinc;
+
+in
+
+{
+
+  ###### interface
+
+  options = {
+
+    services.tinc = {
+
+      networks = mkOption {
+        default = { };
+        type = types.loaOf types.optionSet;
+        description = ''
+          Defines the tinc networks which will be started.
+          Each network invokes a different daemon.
+        '';
+        options = {
+
+          extraConfig = mkOption {
+            default = "";
+            type = types.lines;
+            description = ''
+              Extra lines to add to the tinc service configuration file.
+            '';
+          };
+
+          name = mkOption {
+            default = null;
+            type = types.nullOr types.str;
+            description = ''
+              The name of the node which is used as an identifier when communicating
+              with the remote nodes in the mesh. If null then the hostname of the system
+              is used.
+            '';
+          };
+
+          debugLevel = mkOption {
+            default = 0;
+            type = types.addCheck types.int (l: l >= 0 && l <= 5);
+            description = ''
+              The amount of debugging information to add to the log. 0 means little
+              logging while 5 is the most logging. <command>man tincd</command> for
+              more details.
+            '';
+          };
+
+          hosts = mkOption {
+            default = { };
+            type = types.loaOf types.lines;
+            description = ''
+              The name of the host in the network as well as the configuration for that host.
+              This name should only contain alphanumerics and underscores.
+            '';
+          };
+
+          interfaceType = mkOption {
+            default = "tun";
+            type = types.addCheck types.str (n: n == "tun" || n == "tap");
+            description = ''
+              The type of virtual interface used for the network connection
+            '';
+          };
+
+          package = mkOption {
+            default = pkgs.tinc;
+            description = ''
+              The package to use for the tinc daemon's binary.
+            '';
+          };
+
+        };
+      };
+    };
+
+  };
+
+
+  ###### implementation
+
+  config = mkIf (cfg.networks != { }) {
+
+    environment.etc = fold (a: b: a // b) { }
+      (flip mapAttrsToList cfg.networks (network: data:
+        flip mapAttrs' data.hosts (host: text: nameValuePair
+          ("tinc/${network}/hosts/${host}")
+          ({ mode = "0444"; inherit text; })
+        ) // {
+          "tinc/${network}/tinc.conf" = {
+            mode = "0444";
+            text = ''
+              Name = ${if data.name == null then "$HOST" else data.name}
+              DeviceType = ${data.interfaceType}
+              Device = /dev/net/tun
+              Interface = tinc.${network}
+              ${data.extraConfig}
+            '';
+          };
+        }
+      ));
+
+    networking.interfaces = flip mapAttrs' cfg.networks (network: data: nameValuePair
+      ("tinc.${network}")
+      ({
+        virtual = true;
+        virtualType = "${data.interfaceType}";
+      })
+    );
+
+    systemd.services = flip mapAttrs' cfg.networks (network: data: nameValuePair
+      ("tinc.${network}")
+      ({
+        description = "Tinc Daemon - ${network}";
+        wantedBy = [ "network.target" ];
+        after = [ "network-interfaces.target" ];
+        path = [ data.package ];
+        restartTriggers = [ config.environment.etc."tinc/${network}/tinc.conf".source ]
+          ++ mapAttrsToList (host: _ : config.environment.etc."tinc/${network}/hosts/${host}".source) data.hosts;
+        serviceConfig = {
+          Type = "simple";
+          PIDFile = "/run/tinc.${network}.pid";
+        };
+        preStart = ''
+          mkdir -p /etc/tinc/${network}/hosts
+
+          # Prefer ED25519 keys (only in 1.1+)
+          [ -f "/etc/tinc/${network}/ed25519_key.priv" ] || tinc -n ${network} generate-ed25519-keys
+
+          # Otherwise use RSA keys
+          [ -f "/etc/tinc/${network}/rsa_key.priv" ] || tinc -n ${network} generate-rsa-keys 4096
+        '';
+        script = ''
+          ${data.package}/sbin/tincd -D -U tinc.${network} -n ${network} --pidfile /run/tinc.${network}.pid -d ${toString data.debugLevel}
+        '';
+      })
+    );
+
+    users.extraUsers = flip mapAttrs' cfg.networks (network: _:
+      nameValuePair ("tinc.${network}") ({
+        description = "Tinc daemon user for ${network}";
+      })
+    );
+
+  };
+
+}