Introduce a short feature freeze period before each release

[antoninbas]

I'd like to propose the introduction of a small feature freeze period before each minor release. I believe that doing so would:

• ensure that we can release on time: we systematically release on Fridays instead of Wednesdays, and just before the weekend is not an ideal release time
• help keep the release process more organized: instead of rushing reviews for bug fixes and new features alike during the last couple of days, we would only focus on bug fixes. We could start testing the release early, and in case of test failures we would have enough time to address the bugs or rollback features. It's likely that the days preceding the feature freeze would still be pretty hectic, as everyone tries to get their feature in, but there is no avoiding that. And at least we have a buffer before the release needs to go out, which is reserved for bug fixes.

More concretely I propose:

• The target for all releases is Wednesday at noon PST
• The preceding week (also Wednesday at noon PST) is the feature freeze date: at that time, the release branch is created from the main branch (e.g. release-1.3). From now on, new features can go in the main branch but will not be included in the feature branch.
• Between the feature freeze date and the release date, important bug fixes merged into main can be backported to the release branch (like we would do for a bug fix release) - see https://github.com/antrea-io/antrea/blob/main/docs/contributors/cherry-picks.md

I think that v1.3.0 could be the first release for which we implement this process. Happy to hear everyone's thoughts!

[tnqn]

Sounds good to me!

[antoninbas]

Consensus at the 06/07/2021 Community Meeting is that we will introduce the feature freeze period for v1.3. If it improves the release process, we will adopt this for all subsequent releases.

[antoninbas]

Closing this. We had a feature freeze for v1.3, and we intend to have one for future releases as well.