Draft: Add options to start and stop group replication

[eryx12o45]

SUMMARY
Added options to start and stop group replication

ISSUE TYPE
Feature Pull Request

COMPONENT NAME
mysql_replication module

ADDITIONAL INFORMATION
new version of #93

[Andersson007]

@eryx12o45 hello, thanks for the PR!
Do i understand it correctly that in our case it's tricky to cover this with integration tests? You tested it locally and it works OK, right?

Do others think if it's OK to merge the PR w/o integration testing?

[laurent-indermuehle]

The integration tests have 1 primary and 2 replicas. It should be possible to tests this no?

[eryx12o45]

Hi @Andersson007 and @laurent-indermuehle ,

thanks for your review. I will try to create some tests in the near future. I created this PR in the first place some time back when I was working at another place where we would have needed it, but since then changes jobs and am not working on this anymore. Nevertheless I thought it makes sense to finalize this PR and therefore re-created it with adapted settings. But now I have to build a local test env. I would assume it is possible to test it though. I hope code-wise it's ok for now though

[Andersson007]

Hi @Andersson007 and @laurent-indermuehle ,

thanks for your review. I will try to create some tests in the near future. I created this PR in the first place some time back when I was working at another place where we would have needed it, but since then changes jobs and am not working on this anymore. Nevertheless I thought it makes sense to finalize this PR and therefore re-created it with adapted settings. But now I have to build a local test env. I would assume it is possible to test it though. I hope code-wise it's ok for now though

@eryx12o45 hi, code-wise LGTM. Ideally would be great to have integration tests. If it's tricky (no idea), I'm OK with merging this provided the manual testing is done (though someone can break the code in future and we'll learn about it only via bug reports).
Thoughts @eryx12o45 @laurent-indermuehle ?

[laurent-indermuehle]

@eryx12o45 please have a look at the Makefile. It uses Podman to run the integration tests on your workstation. If you have a question about it you can ask me (either here or in our matrix.

I'm not a fan of incorporating code without proper tests. If down the line Oracle changes something to the group replication, due to the critical nature of the replication, I would like to know about it.

[laurent-indermuehle]

Sorry @eryx12o45, I should have point you to this file: https://github.com/ansible-collections/community.mysql/blob/main/TESTING.md

[Andersson007]

If there are any issue with running tests locally:

• Convert the PR to draft (there's a button on this page)
• Just push your tests and see the results here
• When it's ready, convert it back, there'll be a button for that too

If you have not time at all, I don't know, just say it explicitly, maybe someone else could add testing directly to the PR

[eryx12o45]

Heyho, thanks for pointing me to the docs. As said. I will definitely try to biuild some integration tests, might just take some time, but I promise to try to keep it shorter this time ;-)