munge: add service

nixos/modules/module-list.nix

@@ -326,6 +326,7 @@
   ./services/security/fprot.nix
   ./services/security/frandom.nix
   ./services/security/haveged.nix
+  ./services/security/munge.nix
   ./services/security/torify.nix
   ./services/security/tor.nix
   ./services/security/torsocks.nix

nixos/modules/services/security/munge.nix

@@ -0,0 +1,61 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  cfg = config.services.munge;
+
+in
+
+{
+
+  ###### interface
+
+  options = {
+
+    services.munge = {
+      enable = mkEnableOption "munge service";
+
+      password = mkOption {
+        default = "/etc/munge/munge.key";
+        type = types.string;
+        description = ''
+          The path to a daemon's secret key.
+        '';
+      };
+
+    };
+
+  };
+
+  ###### implementation
+
+  config = mkIf cfg.enable {
+
+    environment.systemPackages = [ pkgs.munge ];
+
+    systemd.services.munged = { 
+      wantedBy = [ "multi-user.target" ];
+      after = [ "network.target" ];
+
+      path = [ pkgs.munge pkgs.coreutils ];
+
+      preStart = ''
+        chmod 0700 ${cfg.password}
+        mkdir -p /var/lib/munge -m 0711
+        mkdir -p /var/log/munge -m 0700
+        mkdir -p /run/munge -m 0755
+      '';
+
+      serviceConfig = {
+        ExecStart = "${pkgs.munge}/bin/munged --syslog --key-file ${cfg.password}";
+        PIDFile = "/run/munge/munged.pid";
+        ExecReload = "${pkgs.coreutils}/bin/kill -HUP $MAINPID";
+      };
+
+    };
+
+  };
+
+}