haka: very basic testing

nixos/tests/haka.nix

@@ -0,0 +1,24 @@
+# This test runs haka and probes it with hakactl
+
+import ./make-test.nix ({ pkgs, ...} : {
+  name = "haka";
+  meta = with pkgs.stdenv.lib.maintainers; {
+    maintainers = [ tvestelind ];
+  };
+
+  nodes = {
+    haka =
+      { config, pkgs, ... }:
+        {
+          services.haka.enable = true;
+        };
+    };
+
+  testScript = ''
+    startAll;
+
+    $haka->waitForUnit("haka.service");
+    $haka->succeed("hakactl status");
+    $haka->succeed("hakactl stop");
+  '';
+})