nixos/nginx: add test for status page

nixos/tests/nginx-status-page.nix

@@ -0,0 +1,72 @@
+import ./make-test-python.nix ({ pkgs, ... }: {
+  name = "nginx-status-page";
+  meta = with pkgs.lib.maintainers; {
+    maintainers = [ h7x4 ];
+  };
+
+  nodes = {
+    webserver = { ... }: {
+      virtualisation.vlans = [ 1 ];
+
+      networking = {
+        useNetworkd = true;
+        useDHCP = false;
+        firewall.enable = false;
+      };
+
+      systemd.network.networks."01-eth1" = {
+        name = "eth1";
+        networkConfig.Address = "10.0.0.1/24";
+      };
+
+      services.nginx = {
+        enable = true;
+        statusPage = true;
+        virtualHosts."localhost".locations."/index.html".return = "200 'hello world\n'";
+      };
+
+      environment.systemPackages = with pkgs; [ curl ];
+    };
+
+    client = { ... }: {
+      virtualisation.vlans = [ 1 ];
+
+      networking = {
+        useNetworkd = true;
+        useDHCP = false;
+        firewall.enable = false;
+      };
+
+      systemd.network.networks."01-eth1" = {
+        name = "eth1";
+        networkConfig.Address = "10.0.0.2/24";
+      };
+
+      environment.systemPackages = with pkgs; [ curl ];
+    };
+  };
+
+  testScript = { nodes, ... }: ''
+    start_all()
+
+    webserver.wait_for_unit("nginx")
+    webserver.wait_for_open_port(80)
+
+    def expect_http_code(node, code, url):
+        http_code = node.succeed(f"curl -w '%{{http_code}}' '{url}'")
+        assert http_code.split("\n")[-1].strip() == code, \
+          f"expected {code} but got following response:\n{http_code}"
+
+    with subtest("localhost can access status page"):
+        expect_http_code(webserver, "200", "http://localhost/nginx_status")
+
+    with subtest("localhost can access other page"):
+        expect_http_code(webserver, "200", "http://localhost/index.html")
+
+    with subtest("client can not access status page"):
+        expect_http_code(client, "403", "http://10.0.0.1/nginx_status")
+
+    with subtest("client can access other page"):
+        expect_http_code(client, "200", "http://10.0.0.1/index.html")
+  '';
+})