Stale branches

[nokute78]

We have 180+ branches as of Dec 18, 2021. I think it's too much.
https://github.com/fluent/fluent-bit/branches

There are some kinds of branches.

1. For release (e.g. master and https://github.com/fluent/fluent-bit/tree/1.8)
2. For pull request
3. For pull request and already merged
4. For testing to check if an issue is fixed or not
5. For developing new feature
6. Other

I think we can remove 3. For pull request and already merged branches.
like

[patrick-stephens]

We may be able to automate this type of cleanup. I can't really see a good reason to keep the branches around once merged.

[patrick-stephens]

@nokute78 @edsiper @niedbalski shall we remove all branches for merged or closed PRs after a specified date announced in Slack, etc. We should ask people to clean theirs up if they can.

We probably should also cover abandoned branches, e.g. no activity in a year, that are not release ones. Maybe ping the people involved to say we'll remove in 30 days to give them time to respond if they want to keep it although it'll be in a local clone unless they've wiped that.

I think we should automate this as well to clean up in future. Branches can be auto deleted on PR merge or closure.

[nokute78]

GitHub supports Automatically delete head branches.
https://docs.github.com/en/repositories/configuring-branches-and-merges-in-your-repository/configuring-pull-request-merges/managing-the-automatic-deletion-of-branches

I think we also need to set branch protection rules.
https://docs.github.com/en/repositories/configuring-branches-and-merges-in-your-repository/defining-the-mergeability-of-pull-requests/managing-a-branch-protection-rule

[nokute78]

I pushed my forked branch, so there is no my branches on fluent/fluent-bit repository.
https://github.com/nokute78/fluent-bit

It is an easy way to prevent creating stale branches on fluent/fluent-bit repo.

[patrick-stephens]

I don't think that setting will auto delete existing merged branches though, it just automates it when a new PR is merged. I agree though it should be on so we can do that: although we need to confirm it has no impact on forks, i.e. contribution from a fork may not want that branch deleting.

We should ask people to clean up their branches first and then force it after a bit of time for the historical ones I think though. I'll ask @edsiper and maybe we also bring up in a community meeting @agup006 ?

We do have some branch protection rules in place currently: https://github.com/calyptia/fluent-bit-infra/blob/a4b0327ac98663c5ec0d20f872affedf5d92e9de/terraform/github.tf#L33
If there are some more to add then best place is a PR there.