Essentially what I would like to do is some docker in docker for testing. In my organization we rely a lot on tests that automatically launch some docker services and then close them when the tests finish. This is integrated with the test frameworks rather than running the containers by hand.
We are actually not using testcontainers but is essentially the same idea, so I thought that since it's rather popular someone might have tried it with dagger. But the core idea behind it is to use docker in docker instead of using dagger service containers (which I really like).