nixos: add module for rmilter

nixos/modules/misc/ids.nix

@@ -247,6 +247,7 @@
       gale = 223;
       matrix-synapse = 224;
       rspamd = 225;
+      rmilter = 226;
 
       # When adding a uid, make sure it doesn't match an existing gid. And don't use uids above 399!
 
@@ -471,6 +472,7 @@
       gale = 223;
       matrix-synapse = 224;
       rspamd = 225;
+      rmilter = 226;
 
       # When adding a gid, make sure it doesn't match an existing
       # uid. Users and groups with the same name should have equal

nixos/modules/module-list.nix

@@ -194,6 +194,7 @@
   ./services/mail/postsrsd.nix
   ./services/mail/spamassassin.nix
   ./services/mail/rspamd.nix
+  ./services/mail/rmilter.nix
   ./services/misc/apache-kafka.nix
   ./services/misc/autofs.nix
   ./services/misc/bepasty.nix

nixos/modules/services/mail/rmilter.nix

@@ -0,0 +1,189 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  rspamdCfg = config.services.rspamd;
+  cfg = config.services.rmilter;
+
+  rmilterConf = ''
+pidfile = /run/rmilter/rmilter.pid;
+bind_socket = ${cfg.bindSocket};
+tempdir = /tmp;
+
+  '' + (with cfg.rspamd; if enable then ''
+spamd {
+        servers = ${concatStringsSep ", " servers};
+        connect_timeout = 1s;
+        results_timeout = 20s;
+        error_time = 10;
+        dead_time = 300;
+        maxerrors = 10;
+        reject_message = "${rejectMessage}";
+        ${optionalString (length whitelist != 0)  "whitelist = ${concatStringsSep ", " whitelist};"}
+
+        # rspamd_metric - metric for using with rspamd
+        # Default: "default"
+        rspamd_metric = "default";
+        ${extraConfig}
+};
+    '' else "") + cfg.extraConfig;
+
+  rmilterConfigFile = pkgs.writeText "rmilter.conf" rmilterConf;
+
+in
+
+{
+
+  ###### interface
+
+  options = {
+
+    services.rmilter = {
+
+      enable = mkOption {
+        default = cfg.rspamd.enable;
+        description = "Whether to run the rmilter daemon.";
+      };
+
+      debug = mkOption {
+        default = false;
+        description = "Whether to run the rmilter daemon in debug mode.";
+      };
+
+      user = mkOption {
+        type = types.string;
+        default = "rmilter";
+        description = ''
+          User to use when no root privileges are required.
+        '';
+       };
+
+      group = mkOption {
+        type = types.string;
+        default = "rmilter";
+        description = ''
+          Group to use when no root privileges are required.
+        '';
+       };
+
+      bindSocket =  mkOption {
+        type = types.string;
+        default = "unix:/run/rmilter/rmilter.sock";
+        description = "Socket to listed for MTA requests";
+        example = ''
+            "unix:/run/rmilter/rmilter.sock" or
+            "inet:11990@127.0.0.1"
+          '';
+      };
+
+      rspamd = {
+        enable = mkOption {
+          default = rspamdCfg.enable;
+          description = "Whether to use rspamd to filter mails";
+        };
+
+        servers = mkOption {
+          type = types.listOf types.str;
+          default = ["r:0.0.0.0:11333"];
+          description = ''
+            Spamd socket definitions.
+            Is server name is prefixed with r: it is rspamd server.
+          '';
+        };
+
+        whitelist = mkOption {
+          type = types.listOf types.str;
+          default = [ ];
+          description = "list of ips or nets that should be not checked with spamd";
+        };
+
+        rejectMessage = mkOption {
+          type = types.str;
+          default = "Spam message rejected; If this is not spam contact abuse";
+          description = "reject message for spam";
+        };
+
+        extraConfig = mkOption {
+          type = types.lines;
+          default = "";
+          description = "Custom snippet to append to end of `spamd' section";
+        };
+      };
+
+      extraConfig = mkOption {
+        type = types.lines;
+        default = "";
+        description = "Custom snippet to append to rmilter config";
+      };
+
+      postfix = {
+        enable = mkOption {
+          type = types.bool;
+          default = false;
+          description = "Add rmilter to postfix main.conf";
+        };
+
+        configFragment = mkOption {
+          type = types.str;
+          description = "Addon to postfix configuration";
+          default = ''
+smtpd_milters = ${cfg.bindSocket}
+# or for TCP socket
+# # smtpd_milters = inet:localhost:9900
+milter_protocol = 6
+milter_mail_macros = i {mail_addr} {client_addr} {client_name} {auth_authen}
+# skip mail without checks if milter will die
+milter_default_action = accept
+          '';
+        };
+      };
+
+    };
+
+  };
+
+
+  ###### implementation
+
+  config = mkIf cfg.enable {
+
+    users.extraUsers = singleton {
+      name = cfg.user;
+      description = "rspamd daemon";
+      uid = config.ids.uids.rmilter;
+      group = cfg.group;
+    };
+
+    users.extraGroups = singleton {
+      name = cfg.group;
+      gid = config.ids.gids.rmilter;
+    };
+
+    systemd.services.rmilter = {
+      description = "Rmilter Service";
+
+      wantedBy = [ "multi-user.target" ];
+      after = [ "network.target" ];
+
+      serviceConfig = {
+        ExecStart = "${pkgs.rmilter}/bin/rmilter ${optionalString cfg.debug "-d"} -n -c ${rmilterConfigFile}";
+        User = cfg.user;
+        Group = cfg.group;
+        PermissionsStartOnly = true;
+        Restart = "always";
+      };
+
+      preStart = ''
+        ${pkgs.coreutils}/bin/mkdir -p /run/rmilter
+        ${pkgs.coreutils}/bin/chown ${cfg.user}:${cfg.group} /run/rmilter
+      '';
+
+    };
+
+    services.postfix.extraConfig = optionalString cfg.postfix.enable cfg.postfix.configFragment;
+
+  };
+
+}