Start & stop Kafka process within running container

[seglo]

Fixes #1233

Add support to stop and start the Kafka broker programmatically without having to stop or start the container (see #1233 for issues with managing container lifetime).

[ennru]

This looks very good.
I wonder how Testcontainers 1.15 affects this. #1225

[seglo]

Thanks. I'm not certain if I'm reproducing "pick up again when the Kafka server comes back up" as was intended. In my local tests the consumer won't usually reset to offset 0, but it will disconnect. On travis it will always reset to 0. I think it's because the broker takes longer to start again, when I manually increase the sleep after the broker stop then I can reproduce the problem locally. The change I made to accommodate both scenarios is to always request the full number of messages produced and assert the tail is correct. In both scenarios the Consumer is reconnecting silently, so I think it satisfies the original intention of the test.

[seglo]

I wonder how Testcontainers 1.15 affects this. #1225

Good question. I was thinking about referencing their 1.15 release, but it's not a final yet. Maybe it will be available before our release.

[bsideup]

@seglo JFYI the "rc" status of 1.15.0 is only for the image-related changes (deprecated constructors & more) that we wanted to evaluate before doing a Big Bang Release :)
The "core" API is stable (not to mention that we care deeply about the backward compatibility) and it is safe to use now. Also, I am not planning to touch Kafka's internals any time soon, so I'd say you're good to go with rc2 unless you have a super strict & restrictive policy irt dependency versions.

[seglo]

@bsideup Thanks for the info. We'll give the RC a test run before our release to confirm our use case is still working as expected.

[ennru]

LGTM.

[ennru]

This has been backported to the release-2.0.x branch to be part of 2.0.6.