postgrey: extended configuration

nixos/modules/services/mail/postgrey.nix

@@ -4,6 +4,39 @@ with lib; let
 
   cfg = config.services.postgrey;
 
+  natural = with types; addCheck int (x: x >= 0);
+  natural' = with types; addCheck int (x: x > 0);
+
+  socket = with types; addCheck (either (submodule unixSocket) (submodule inetSocket)) (x: x ? "path" || x ? "port");
+
+  inetSocket = with types; {
+    addr = mkOption {
+      type = nullOr string;
+      default = null;
+      example = "127.0.0.1";
+      description = "The address to bind to. Localhost if null";
+    };
+    port = mkOption {
+      type = natural';
+      default = 10030;
+      description = "Tcp port to bind to";
+    };
+  };
+
+  unixSocket = with types; {
+    path = mkOption {
+      type = path;
+      default = "/var/run/postgrey.sock";
+      description = "Path of the unix socket";
+    };
+
+    mode = mkOption {
+      type = string;
+      default = "0777";
+      description = "Mode of the unix socket";
+    };
+  };
+
 in {
 
   options = {
@@ -13,21 +46,68 @@ in {
         default = false;
         description = "Whether to run the Postgrey daemon";
       };
-      inetAddr = mkOption {
-        type = nullOr string;
-        default = null;
-        example = "127.0.0.1";
-        description = "The inet address to bind to. If none given, bind to /var/run/postgrey.sock";
-      };
-      inetPort = mkOption {
-        type = int;
-        default = 10030;
-        description = "The tcp port to bind to";
+      socket = mkOption {
+        type = socket;
+        default = { path = "/var/run/postgrey.sock"; };
+        example = {
+          addr = "127.0.0.1";
+          port = 10030;
+        };
+        description = "Socket to bind to";
       };
       greylistText = mkOption {
         type = string;
         default = "Greylisted for %%s seconds";
-        description = "Response status text for greylisted messages";
+        description = "Response status text for greylisted messages; use %%s for seconds left until greylisting is over and %%r for mail domain of recipient";
+      };
+      greylistAction = mkOption {
+        type = string;
+        default = "DEFER_IF_PERMIT";
+        description = "Response status for greylisted messages (see access(5))";
+      };
+      greylistHeader = mkOption {
+        type = string;
+        default = "X-Greylist: delayed %%t seconds by postgrey-%%v at %%h; %%d";
+        description = "Prepend header to greylisted mails; use %%t for seconds delayed due to greylisting, %%v for the version of postgrey, %%d for the date, and %%h for the host";
+      };
+      delay = mkOption {
+        type = natural;
+        default = 300;
+        description = "Greylist for N seconds";
+      };
+      maxAge = mkOption {
+        type = natural;
+        default = 35;
+        description = "Delete entries from whitelist if they haven't been seen for N days";
+      };
+      retryWindow = mkOption {
+        type = either string natural;
+        default = 2;
+        example = "12h";
+        description = "Allow N days for the first retry. Use string with appended 'h' to specify time in hours";
+      };
+      lookupBySubnet = mkOption {
+        type = bool;
+        default = true;
+        description = "Strip the last N bits from IP addresses, determined by IPv4CIDR and IPv6CIDR";
+      };
+      IPv4CIDR = mkOption {
+        type = natural;
+        default = 24;
+      };
+      IPv6CIDR = mkOption {
+        type = natural;
+        default = 64;
+      };
+      privacy = mkOption {
+        type = bool;
+        default = true;
+        description = "Store data using one-way hash functions (SHA1)";
+      };
+      autoWhitelist = mkOption {
+        type = nullOr natural';
+        default = 5;
+        description = "Whitelist clients after successful delivery of N messages";
       };
     };
   };
@@ -52,10 +132,10 @@ in {
     };
 
     systemd.services.postgrey = let
-      bind-flag = if isNull cfg.inetAddr then
-        "--unix=/var/run/postgrey.sock"
+      bind-flag = if cfg.socket ? "path" then
+        ''--unix=${cfg.socket.path} --socketmode=${cfg.socket.mode}''
       else
-        "--inet=${cfg.inetAddr}:${cfg.inetPort}";
+        ''--inet=${optionalString (cfg.socket.addr != null) (cfg.socket.addr + ":")}${cfg.socket.port}'';
     in {
       description = "Postfix Greylisting Service";
       wantedBy = [ "multi-user.target" ];
@@ -67,7 +147,7 @@ in {
       '';
       serviceConfig = {
         Type = "simple";
-        ExecStart = ''${pkgs.postgrey}/bin/postgrey ${bind-flag} --pidfile=/var/run/postgrey.pid --group=postgrey --user=postgrey --dbdir=/var/postgrey --greylist-text="${cfg.greylistText}"'';
+        ExecStart = ''${pkgs.postgrey}/bin/postgrey ${bind-flag} --group=postgrey --user=postgrey --dbdir=/var/postgrey --delay=${cfg.delay} --max-age=${cfg.maxAge} --retry-window=${cfg.retryWindow} ${if cfg.lookupBySubnet then "--lookup-by-subnet" else "--lookup-by-host"} --ipv4cidr=${cfg.IPv4CIDR} --ipv6cidr=${cfg.IPv6CIDR} ${optionalString cfg.privacy "--privacy"} --auto-whitelist-clients=${if cfg.autoWhitelist == null then "0" else cfg.autoWhitelist} --greylist-text="${cfg.greylistText}" --x-greylist-header="${cfg.greylistHeader}" --greylist-action=${cfg.greylistAction}'';
         Restart = "always";
         RestartSec = 5;
         TimeoutSec = 10;