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Release Phases

Enhancements Freeze

All enhancements wishing to be included in the current release must have

  • A KEP in an implementable state
    • Including Testing Plans
    • Including Graduation Criteria
  • An open issue in the Release Milestone

If the enhancement does not meet these requirements, it will be removed from the milestone and will require an Exception.


Several weeks prior to Code Freeze, we increase the cadence of release team meetings to begin tracking work more closely. We call this Burndown, because at this point we have a list of outstanding issues and PRs, and are actively working to burn that list down. SIG representatives will be asked to attend if their SIG has specific outstanding issues that are blocking the release.

Please subscribe to the Kubernetes Release Calendar to see meeting events. Burndown meetings may conflict with other community meetings. Please prioritize this meeting if a member of the release team asks you to attend.

The intent of these meetings is to:

  • Focus on fixing bugs, eliminating test flakes and general release stabilization.
  • Ensure docs and release notes are written and accurate.
  • Identify all enhancement going into the release, and make sure alpha, beta, GA is marked in enhancements repo.
  • Provide a one-stop view of release progress via the current meeting notes (TODO: link to the template?) including relevant release metrics.

Code Freeze

All enhancements going into the release must be code-complete, including tests, and have docs PRs open by the due date.

The docs PRs don't have to be ready to merge, but it should be clear what the topic will be and who is responsible for writing it. This person will become the primary contact for the documentation lead. It’s incredibly important that documentation work gets completed as quickly as possible.

At this point, only release-blocking issues and PRs within the milestone are allowed to be merged.

Test Freeze

The date after which no more tests may be changed (or promoted to Conformance), unless there are release-blocking or other exceptional reasons. Before this date, it is acceptable to improve test coverage of existing code. After this date, the goal is to fix, revert, or remove tests that are failing.

Every merged PR, which is part of the current milestone and therefore merged into the master branch, will be automatically merged into the release branch via the periodic release branch fast forward job in prow.


Thaw specifies the end of both Code Freeze and Test Freeze. At this point it is expected that all outstanding PRs for the release of Kubernetes have been merged into the release branch. Assuming the release team agrees, Code Freeze, will be lifted, and we enter Thaw. This means from a technical perspective, that now the master and release-1.x branch diverge. After Thaw, the master branch develops toward the next minor release and the release branch goes into maintenance mode. From this point forward, any PRs intended for the current release must be cherry-picked into the appropriate branch.



Starting at Enhancements Freeze, the release team will solicit and rule on Exception requests for enhancements and test work that is unlikely to be done by Code Freeze. The Exception approval is the responsibility of the SIG or SIGs labeled in the pull request. The release team may intervene or deny the request only if it poses a risk to release quality, or could negatively impact the overall timeline. Changes introduced at this point should be well-tested, well-understood, limited in architectural scope, and low risk. All of those factors should be considered in the approval process. Enhancements on an feature branch with documentation, test cases, and passing CI are more likely to be accepted.

Feature Blog Freeze

Feature blogs are an amazing way to showcase all the hard work you and your team have done with the enhancement. While providing technical depth in terms of content, they are also great avenues to attract newer contributors to the Kubernetes project. You can opt in to write a feature blog for your enhancement and this deadline is to freeze the collection phase for the ongoing cycle. Once the collection phase is completed, the Release Comms team will coordinate further with you to work out details around delivery & review.

After the deadline passes if you haven't opted in & still would like to have a feature blog for your enhancement, please contact the current release communications lead on the #sig-release channel in Kubernetes Slack.


Enhancements that are partially implemented and/or lack sufficient tests may be considered for pruning beginning after Code Freeze, unless they've been granted an Exception.

The release team will work with SIGs and enhancements owners to evaluate each case, but for example, pruning could include actions such as:

  • Disabling the use of a new API or field
  • Switching the default value of a flag or field
  • Moving a new API or field behind an Alpha Enhancements gate
  • Reverting commits or deleting code

This should occur before 1.x.0-beta.1 is cut so we have time to gather signal on whether the system is stable in this state. These are considered drastic measures, so the release team will strive to coordinate at-risk work with SIGs before this time. The goal is to make code freeze, and overall project transparency, enforceable despite the lack of a consistently used feature branch process.


If an enhancement needs documentation, enter "Yes" in the enhancement tracking spreadsheet and add a link to the documentation PR. You can open documentation PRs in the kubernetes/website repository. If you have questions, the release documentation lead, or representatives from SIG-Docs will be happy to assist you.

For documentation PRs:

  • Open PRs against the dev-1.x branch based off of the current release PR. The documentation workflow uses feature branches for release documentation, rather than basing from master. Be sure to open your PR against the release branch.
  • Add your PR to the current Release milestone.