The goal of this document is to describe and explain work-flow for maintenance branches. It does not affect development in master except of merging of fixes from maintenance branch. It is not goal of this document to discuss which way is better for pull requests or how to use the git in exact situations.
Why Maintenance Branches?
YaST uses maintenance branches because it is easier to track patches for already released products in git then in Build Service. It gives ability to easy review of fixes and also to merge fixes in master branch, to avoid forgotten ones.
The default maintenance workflow is to fix it in the oldest applicable branch and then merge to the newer ones.
The following rules apply to working with maintenance branches:
cherry-pickas part of common work-flow. In a nutshell, cherry-picking changes the SHA because the commit will get a new parent commit. And with different SHAs, it is difficult to find out if all desired commits from the branch are now also in master. For deeper explanation see these articles 1, 2 or reddit)
- merge new maintenance branches to master regularly
- create fix for the oldest applicable branch first
The first and main reason is that it allows easy tracking whether a fix in a commit is also in newer branches and master. The second reason is that it produces a nicer git tree structure which allows to see which code stream is affected by which fix. The easiest way to see if some commits are missing is to use the GitHub UI and compare branches.
It can be done also on the command line:
Example how to check what fixes are not merged:
git pull git log origin/master..origin/SLE-12-GA # if nothing appears then all are merged
Examples how to see the git tree:
gitk --all # to get a GUI git log --graph --pretty=oneline --abbrev-commit --decorate --all
Let's say we have SLE-12-GA, SLE-12-SP1 and master branches:
git checkout SLE-12-GA git pull git checkout -b my_fix_SLE12 # branch based on SLE-12-GA ..hacking... git commit git push # wait for review and merge # Merge SLE-12-GA into SLE-12-SP1 git checkout SLE-12-SP1 git pull git checkout -b my_fix_sp1 # branch based on SLE-12-SP1 git merge origin/SLE-12-GA # to ensure that we use recent branch on remote # fix possible conflicts and git commit if needed... git push # And now merge SLE-12-SP1 into master git checkout master git pull git checkout -b my_fix_master # branch based on master git merge origin/SLE-12-SP1 # to ensure that we use recent branch on remote # fix possible conflicts and git commit if needed... git push
Branch Specific Commits
A maintenance branch usually contains commits that switch e.g. CI and Docker file
to its own target. If a merge contains this commit, simply use
git revert <commit>. This will revert it even for future.
When backporting a fix from Ruby to YCP it is recommended to write it from scratch as there is no ruby2ycp converter.
For the other way around, when first a fix is in YCP and then needed in Ruby,
converter can be used, but the recommended way is to write it also from scratch
because the result will be a much nicer Ruby code.
Merge Has More Commits
While merging, sometimes we see more commits than expected. This can happen if someone forgot to merge earlier. In this case, you should be the hero and also merge all the pending commits into the newer branches. If there are conflicts, you should follow these strategies in order to fix them (in that order):
- Resolve conflicts manually.
- Merge using
git merge -s ours.
-s ours should be applied as a last resort. That option would join the branch
histories but apply no code from the older branch. This would be necessary in special repos
in which there is a big divergence between products (e.g., from SLE-12 to SLE-15).
When a maintenance fix was not requested and made only in master and then
requested to backport to a maintenance branch, it is still needed to
cherry-pick used for backporting the fix so we are still sure that nothing is missing.
Example how to backport a fix and then merge the branch back
git checkout SLE-12-GA git pull git checkout -b my_fix_SLE12 git cherry-pick <fix from master> ...possible conflict resolution git commit git push # wait for review and merge git checkout master git pull git merge origin/SLE-12-GA ...fix possible conflicts and git commit if needed... git push # wait until a review passes, then merge to master
How to Submit a Maintenance Request
For master it is handled by Jenkins and no work is needed.
For branches that contain a
ensure that the version has been increased and call
For branches without a
Rakefile, create the source tarball and follow the
How to Create a Maintenance Branch
When a maintenance branch needs to be created, there is a helper tool available in devtools. Execute it without arguments to see usage instructions.
Maintenance Branch Naming
Already known names for branches:
SLE-10: SLE 10 GA
SLE-10-SP*: SLE 10 Service packs
Code-11: SLE 11 GA
Code-11-SP*: SLE 11 Service packs
SLE-*-GA: SLE 12 and later GAs
SLE-*-SP*: SLE 12 and later Service packs
openSUSE-1*: respective openSUSE release
openSUSE-4*: openSUSE leap releases (see below)
Maintenance branches for Leap only make sense for a few repositories.
For most YaST packages, openSUSE Leap and SLE share the same code and
maintenance updates and, thus, only the corresponding
branch is used. Leap maintenance branches will be created manually in a case by
case basis, only when needed and only for repositories that affect openSUSE but
Working with SLE 10 and SLE 11
These older code streams do not use the familiar Rake tasks, and the system libraries they may expect is probably significantly different from your workstation.
Maintenance-made-easy is a tool that uses OBS chroots to help you make and submit packages for SLE 10 and SLE 11.
How to find if maintenance branch is still actively maintained
NOTE: It uses SUSE internal tools, as it contain non public data about long term support.
Connect to DE network and run
/work/src/bin/is_maintained <pkg_name>. If it failed, then to show
why osc failed, use
-r which can indicate e.g. missing .oscrc file with credentials.