Backporting to stable/branches

Since murano is a big-tent OS project it largely follows the OpenStack stable branch guide

Upstream support phases

  1. Phase I (first 6 months): All bugfixes (which meet the stable port criteria, described in OS stable branch policy) are appropriate

  2. Phase II (6-12 months): Only critical bugfixes and security patches are acceptable

  3. Phase III (more than 12 months): Only security patches are acceptable

In order to accept a change into $release it must first be accepted into all releases back to master.

There are two notable exceptions to the support phases rule:

  • murano-apps repository: We recognise, that murano apps have different lifecycle than main murano repository. Most of the time new apps are being written for already released versions of murano, not for master. Having a rich collection of apps is one of the goals of murano-apps repository, therefore we accept backports of apps and app features to previous release branches. This is done on a case by case basis and should be discussed with PTL and Murano core members on IRC or Mailing List. However we believe, that submitting an app to stable branch only means that author of the patch is not going to support the app. Therefore for the app to get backported it still has to be first accepted to master and all subsequent releases.

  • murano core library patches: Murano Core Library is an app, that provides core functionality and classes for other murano apps. It shares a lot of properties of regular murano apps and the rationale behind allowing backports of MuranoPL code from master to stable branches is basically the same: low regression risks during upgrades, high adoption impact. However since core library is much more sensitive app, backports to it should be taken more seriously and should be discussed on IRC and Mailing List and receive PTL’s approval.

These two exceptions do not mean, that we’re free to backport any code from master to stable branches. Instead they show, that murano team recognises the importance of these two areas of murano project and treats exceptions to those slightly more liberally than to other parts of murano project.

Bug nomination process

Whenever you file a bug, or see a bug, that you think is eligible for backporting in stable branch nominate it for the corresponding series. If bug reporter does not nominate the bug for eligible branch — this is done by murano bug supervisor during triaging/confirmation process. In case it is not clear whether the bug is eligible or not or if you do not have permissions to nominate a bug for series you can set $release-backport-potential tag (for example liberty-backport-potential). Murano team is holding bi-weekly meetings on IRC (as part of regular community meetings) to triage and nominate bugs for stable backports.