nixos/snmpd: add nixos test

nixos/tests/all-tests.nix

@@ -765,6 +765,7 @@ in {
   sing-box = handleTest ./sing-box.nix {};
   slimserver = handleTest ./slimserver.nix {};
   slurm = handleTest ./slurm.nix {};
+  snmpd = handleTest ./snmpd.nix {};
   smokeping = handleTest ./smokeping.nix {};
   snapcast = handleTest ./snapcast.nix {};
   snapper = handleTest ./snapper.nix {};

nixos/tests/snmpd.nix

@@ -0,0 +1,23 @@
+import ./make-test-python.nix ({ pkgs, lib, ... }: {
+  name = "snmpd";
+
+  nodes.snmpd = {
+    environment.systemPackages = with pkgs; [
+      net-snmp
+    ];
+
+    services.snmpd = {
+      enable = true;
+      configText = ''
+        rocommunity public
+      '';
+    };
+  };
+
+  testScript = ''
+    start_all();
+    machine.wait_for_unit("snmpd.service")
+    machine.succeed("snmpwalk -v 2c -c public localhost | grep SNMPv2-MIB::sysName.0");
+  '';
+
+})