nixos/mosquitto: add test

nixos/tests/all-tests.nix

@@ -143,6 +143,7 @@ in
   misc = handleTest ./misc.nix {};
   mongodb = handleTest ./mongodb.nix {};
   morty = handleTest ./morty.nix {};
+  mosquitto = handleTest ./mosquitto.nix {};
   mpd = handleTest ./mpd.nix {};
   mumble = handleTest ./mumble.nix {};
   munin = handleTest ./munin.nix {};

nixos/tests/mosquitto.nix

@@ -0,0 +1,69 @@
+import ./make-test.nix ({ pkgs, ... }:
+
+let
+  port = 1888;
+  username = "mqtt";
+  password = "VERY_secret";
+  topic = "test/foo";
+
+  cmd = bin: pkgs.lib.concatStringsSep " " [
+    "${pkgs.mosquitto}/bin/mosquitto_${bin}"
+    "-V mqttv311"
+    "-h server"
+    "-p ${toString port}"
+    "-u ${username}"
+    "-P '${password}'"
+    "-t ${topic}"
+  ];
+
+in rec {
+  name = "mosquitto";
+  meta = with pkgs.stdenv.lib; {
+    maintainers = with maintainers; [ peterhoeg ];
+  };
+
+  nodes = let
+    client = { pkgs, ... }: {
+      environment.systemPackages = with pkgs; [ mosquitto ];
+    };
+  in {
+    server = { pkgs, ... }: {
+      networking.firewall.allowedTCPPorts = [ port ];
+      services.mosquitto = {
+        inherit port;
+        enable = true;
+        host = "0.0.0.0";
+        checkPasswords = true;
+        users."${username}" = {
+          inherit password;
+          acl = [
+            "topic readwrite ${topic}"
+          ];
+        };
+      };
+    };
+
+    client1 = client;
+    client2 = client;
+  };
+
+  testScript = let
+    file = "/tmp/msg";
+    payload = "wootWOOT";
+  in ''
+    startAll;
+    $server->waitForUnit("mosquitto.service");
+
+    $server->fail("test -f ${file}");
+    $server->execute("(${cmd "sub"} -C 1 | tee ${file} &)");
+
+    $client1->fail("test -f ${file}");
+    $client1->execute("(${cmd "sub"} -C 1 | tee ${file} &)");
+
+    $client2->succeed("${cmd "pub"} -m ${payload}");
+
+    $server->succeed("grep -q ${payload} ${file}");
+
+    $client1->succeed("grep -q ${payload} ${file}");
+  '';
+})