ci: Add tests for the virtual-path routing

@gregsymons test cases were too outdated to be ported easily. The new
tests should include the coverage of the old ones.

test/test_virtual-path/test_virtual_paths.py

@@ -0,0 +1,59 @@
+from time import sleep
+
+import pytest
+from docker.errors import NotFound
+
+@pytest.mark.parametrize("stub,expected_port", [
+    ("nginx-proxy.test/web1", 81),
+    ("nginx-proxy.test/web2", 82),
+    ("nginx-proxy.test", 83),
+    ("foo.nginx-proxy.test", 42),
+])
+def test_valid_path(docker_compose, nginxproxy, stub, expected_port):
+    r = nginxproxy.get(f"http://{stub}/port")
+    assert r.status_code == 200
+    assert r.text == f"answer from port {expected_port}\n"
+
+@pytest.mark.parametrize("stub", [
+    "nginx-proxy.test/foo",
+    "bar.nginx-proxy.test",
+])
+def test_invalid_path(docker_compose, nginxproxy, stub):
+    r = nginxproxy.get(f"http://{stub}/port")
+    assert r.status_code in [404, 503]
+
+@pytest.fixture()
+def web4(docker_compose):
+    """
+    pytest fixture creating a web container with `VIRTUAL_HOST=nginx-proxy.test`, `VIRTUAL_PATH=/web4/` and `VIRTUAL_DEST=/` listening on port 84.
+    """
+    container = docker_compose.containers.run(
+        name="web4",
+        image="web",
+        detach=True,
+        environment={
+            "WEB_PORTS": "84",
+            "VIRTUAL_HOST": "nginx-proxy.test",
+            "VIRTUAL_PATH": "/web4/",
+            "VIRTUAL_DEST": "/",
+        },
+        ports={"84/tcp": None}
+    )
+    sleep(2)  # give it some time to initialize and for docker-gen to detect it
+    yield container
+    try:
+        docker_compose.containers.get("web4").remove(force=True)
+    except NotFound:
+        pass
+
+"""
+Test if we can add and remove a single virtual_path from multiple ones on the same subdomain.
+"""
+def test_container_hotplug(web4, nginxproxy):
+    r = nginxproxy.get(f"http://nginx-proxy.test/web4/port")
+    assert r.status_code == 200
+    assert r.text == f"answer from port 84\n"
+    web4.remove(force=True)
+    sleep(2)
+    r = nginxproxy.get(f"http://nginx-proxy.test/web4/port")
+    assert r.status_code == 404