How to spin up a subset of services from a docker-compose.yml

[MartyMcFlyInTheSky]

Is there a way to advise pytest-docker to spin up just a subset of all the services declared in the docker-compose.yml?

e.g. the same as the command equivalent:

docker compose -f docker-compose.yml up --build mock1 mock2

(when there might be also mock3 mock4... declared in docker-compose.yml)

[greg-offerfit]

You just override the docker_setup fixture. The README says to use it as part of the process to guarantee you're fully recreating the service, but it's just the commands for docker-compose up in general.

I'd personally like another fixture to control this a bit more obviously, but it's not a big deal.

# Stop the stack before starting a new one
@pytest.fixture(scope="session")
def docker_setup():
    return ["down -v", "up mock1 mock2 --build -d"]

[midoriao]

I’ve been doing something similar.

In my case, though, the setup was a bit more involved—the required services differ per test function, so just overriding docker_setup fixture didn't quite fit. A typical usecase is debugging only the test related to mock1, while other tests depend on mock2. The current behavior still spins up alll services, which is wasteful.

I've worked around it by pytest's "passing data to fixtures" pattern. Minimal example:

@pytest.fixture(scope="function") # Assuming '--container-scope function' in the config
def docker_setup(request):
    marker = request.node.get_closest_marker("docker_required_services")
    required_services = marker.args if marker else []
    cmd_args = ' '.join(required_services)
    return [f'up --build -d {cmd_args}']

@pytest.mark.docker_required_services("mock1", "mock2")
def test_with_all(docker_services):
    ...

@pytest.mark.docker_required_services("mock1")
def test_with_mock1(docker_services):
    ...

This only supports scope='function' for simplicity, but extending it to class/module/session scopes would be technically okay.

I also agree that adding better support for selective services would be a good direction.