initial commit

modules/zmotd.nix

@@ -0,0 +1,62 @@
+{ lib, pkgs, config, ... }:
+{
+  options.services.zmotd = {
+    enable = lib.mkEnableOption "zmotd";
+    interval = lib.mkOption {
+      default = "5m";
+      example = "5m";
+      description = "Change the timing of zmotd runs.";
+      type = lib.types.str;
+    };
+    config = lib.mkOption {
+      default = {
+        entries = [
+          { m = "hostname"; f = "fig"; }
+          { m = "distro"; }
+          { m = "kernel"; }
+          { m = "load"; }
+          { m = "uptime"; }
+        ];
+      };
+      type = lib.types.attrsOf lib.types.anything;
+    };
+    motdFile = lib.mkOption {
+      default = "/etc/motd";
+      description = "Change the where zmotd outputs to.";
+    };
+  };
+
+  config = lib.mkIf config.services.zmotd.enable {
+    users.motdFile = config.services.zmotd.motdFile;
+    systemd.services.zmotd = {
+      description = "Generate dynamic MOTD using zmotd";
+      enable = config.services.zmotd.enable;
+
+      serviceConfig = {
+        Type = "oneshot";
+        User = "root";
+        Group = "root";
+        ExecStart = let
+          motdFile = config.services.zmotd.motdFile;
+          configFile = pkgs.writers.writeTOML
+            "zmotd-config.toml"
+            config.services.zmotd.config;
+        in pkgs.writeShellScript "zmotd-wrapper" ''
+          ${pkgs.zmotd}/bin/zmotd ${configFile} > ${motdFile}
+        '';
+      };
+    };
+    systemd.timers.zmotd = {
+      description = "Regenerate MOTD often";
+      enable = config.services.zmotd.enable;
+
+      wantedBy = [ "timers.target" ];
+      timerConfig = {
+        OnActiveSec = "0s";
+        OnUnitActiveSec = config.services.zmotd.interval;
+        Unit = "zmotd.service";
+        Persistent = true;
+      };
+    };
+  };
+}