polipo: new service expression

nixos/modules/misc/ids.nix

@@ -136,6 +136,7 @@
       nsd = 126;
       gitolite = 127;
       znc = 128;
+      polipo = 129;
 
       # When adding a uid, make sure it doesn't match an existing gid. And don't use uids above 399!
 
@@ -246,6 +247,7 @@
       nsd = 126;
       firebird = 127;
       znc = 128;
+      polipo = 129;
 
       # When adding a gid, make sure it doesn't match an existing uid. And don't use gids above 399!
 

nixos/modules/module-list.nix

@@ -215,6 +215,7 @@
   ./services/networking/openfire.nix
   ./services/networking/openvpn.nix
   ./services/networking/prayer.nix
+  ./services/networking/polipo.nix
   ./services/networking/privoxy.nix
   ./services/networking/quassel.nix
   ./services/networking/radicale.nix

nixos/modules/services/networking/polipo.nix

@@ -0,0 +1,118 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  cfg = config.services.polipo;
+
+  polipoConfig = pkgs.writeText "polipo.conf" ''
+    proxyAddress = ${cfg.proxyAddress}
+    proxyPort = ${toString cfg.proxyPort}
+    allowedClients = ${concatStringsSep ", " cfg.allowedClients}
+    ${optionalString (cfg.parentProxy != "") "parentProxy = ${cfg.parentProxy}" }
+    ${optionalString (cfg.socksParentProxy != "") "socksParentProxy = ${cfg.socksParentProxy}" }
+    ${config.services.polipo.extraConfig}
+  '';
+
+in
+
+{
+
+  options = {
+
+    services.polipo = {
+
+      enable = mkOption {
+        type = types.bool;
+        default = false;
+        description = "Whether to run the polipo caching web proxy.";
+      };
+
+      proxyAddress = mkOption {
+        type = types.string;
+        default = "127.0.0.1";
+        description = "IP address on which Polipo will listen.";
+      };
+
+      proxyPort = mkOption {
+        type = types.int;
+        default = 8123;
+        description = "TCP port on which Polipo will listen.";
+      };
+
+      allowedClients = mkOption {
+        type = types.listOf types.string;
+        default = [ "127.0.0.1" "::1" ];
+        example = [ "127.0.0.1" "::1" "134.157.168.0/24" "2001:660:116::/48" ];
+        description = ''
+          List of IP addresses or network addresses that may connect to Polipo.
+        '';
+      };
+
+      parentProxy = mkOption {
+        type = types.string;
+        default = "";
+        example = "localhost:8124";
+        description = ''
+          Hostname and port number of an HTTP parent proxy;
+          it should have the form ‘host:port’.
+        '';
+      };
+
+      socksParentProxy = mkOption {
+        type = types.string;
+        default = "";
+        example = "localhost:9050";
+        description = ''
+          Hostname and port number of an SOCKS parent proxy;
+          it should have the form ‘host:port’.
+        '';
+      };
+
+      extraConfig = mkOption {
+        type = types.lines;
+        default = "";
+        description = ''
+          Polio configuration. Contents will be added 
+          verbatim to the configuration file.
+        '';
+      };
+
+    };
+
+  };
+
+  config = mkIf cfg.enable {
+
+    users.extraUsers = singleton
+      { name = "polipo";
+        uid = config.ids.uids.polipo;
+        description = "Polipo caching proxy user";
+        home = "/var/cache/polipo";
+        createHome = true;
+      };
+
+    users.extraGroups = singleton
+      { name = "polipo";
+        gid = config.ids.gids.polipo;
+        members = [ "polipo" ];
+      };
+
+    systemd.services.polipo = {
+      description = "caching web proxy";
+      after = [ "network.target" "nss-lookup.target" ];
+      wantedBy = [ "multi-user.target"];
+      preStart = ''
+         ${pkgs.coreutils}/bin/chown polipo:polipo /var/cache/polipo -R
+      '';
+      serviceConfig = {
+        ExecStart  = "${pkgs.polipo}/bin/polipo -c ${polipoConfig}";
+        ExecReload = "${pkgs.coreutils}/bin/kill -USR1 $MAINPID";
+        User = "polipo";
+      };
+    };
+
+  };
+
+}