Swarm support about pytest-docker

[pyhedgehog]

You can add following fixtures and it will be almost all required "support":

@pytest.fixture(scope="session")
def docker_compose_command():
    return "docker stack"
@pytest.fixture(scope="session")
def docker_cleanup():
    return ["up"]
@pytest.fixture(scope="session")
def docker_cleanup():
    return ["down"]
@pytest.fixture(scope="session")
def docker_ip() -> str:
    info = json.loads(pytest_docker.plugin.execute("docker info -f json"))
    if info["Name"] == os.environ.get("HOSTNAME"):
        return "127.0.0.1"
    return info.get("Swarm",{}).get("NodeAddr")