nixos/adguardhome: init (#120568)

nixos/modules/module-list.nix

@@ -632,6 +632,7 @@
   ./services/network-filesystems/xtreemfs.nix
   ./services/network-filesystems/ceph.nix
   ./services/networking/3proxy.nix
+  ./services/networking/adguardhome.nix
   ./services/networking/amuled.nix
   ./services/networking/aria2.nix
   ./services/networking/asterisk.nix

nixos/modules/services/networking/adguardhome.nix

@@ -0,0 +1,78 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.adguardhome;
+
+  args = concatStringsSep " " ([
+    "--no-check-update"
+    "--pidfile /run/AdGuardHome/AdGuardHome.pid"
+    "--work-dir /var/lib/AdGuardHome/"
+    "--config /var/lib/AdGuardHome/AdGuardHome.yaml"
+    "--host ${cfg.host}"
+    "--port ${toString cfg.port}"
+  ] ++ cfg.extraArgs);
+
+in
+{
+  options.services.adguardhome = with types; {
+    enable = mkEnableOption "AdGuard Home network-wide ad blocker";
+
+    host = mkOption {
+      default = "0.0.0.0";
+      type = str;
+      description = ''
+        Host address to bind HTTP server to.
+      '';
+    };
+
+    port = mkOption {
+      default = 3000;
+      type = port;
+      description = ''
+        Port to serve HTTP pages on.
+      '';
+    };
+
+    openFirewall = mkOption {
+      default = false;
+      type = bool;
+      description = ''
+        Open ports in the firewall for the AdGuard Home web interface. Does not
+        open the port needed to access the DNS resolver.
+      '';
+    };
+
+    extraArgs = mkOption {
+      default = [ ];
+      type = listOf str;
+      description = ''
+        Extra command line parameters to be passed to the adguardhome binary.
+      '';
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd.services.adguardhome = {
+      description = "AdGuard Home: Network-level blocker";
+      after = [ "syslog.target" "network.target" ];
+      wantedBy = [ "multi-user.target" ];
+      unitConfig = {
+        StartLimitIntervalSec = 5;
+        StartLimitBurst = 10;
+      };
+      serviceConfig = {
+        DynamicUser = true;
+        ExecStart = "${pkgs.adguardhome}/bin/adguardhome ${args}";
+        AmbientCapabilities = [ "CAP_NET_BIND_SERVICE" ];
+        Restart = "always";
+        RestartSec = 10;
+        RuntimeDirectory = "AdGuardHome";
+        StateDirectory = "AdGuardHome";
+      };
+    };
+
+    networking.firewall.allowedTCPPorts = mkIf cfg.openFirewall [ cfg.port ];
+  };
+}