nixos/tomcat: add basic test case using the example app

nixos/tests/all-tests.nix

@@ -524,6 +524,7 @@ in
   tinc = handleTest ./tinc {};
   tinydns = handleTest ./tinydns.nix {};
   tinywl = handleTest ./tinywl.nix {};
+  tomcat = handleTest ./tomcat.nix {};
   tor = handleTest ./tor.nix {};
   # traefik test relies on docker-containers
   traefik = handleTestOn ["x86_64-linux"] ./traefik.nix {};

nixos/tests/tomcat.nix

@@ -0,0 +1,21 @@
+import ./make-test-python.nix ({ pkgs, ... }:
+
+{
+  name = "tomcat";
+
+  machine = { pkgs, ... }: {
+    services.tomcat.enable = true;
+  };
+
+  testScript = ''
+    machine.wait_for_unit("tomcat.service")
+    machine.wait_for_open_port(8080)
+    machine.wait_for_file("/var/tomcat/webapps/examples");
+    machine.succeed(
+        "curl --fail http://localhost:8080/examples/servlets/servlet/HelloWorldExample | grep 'Hello World!'"
+    )
+    machine.succeed(
+        "curl --fail http://localhost:8080/examples/jsp/jsp2/simpletag/hello.jsp | grep 'Hello, world!'"
+    )
+  '';
+})