Ceph » Stable releases

Before a backported commit can be merged into the release branch, it must be tested in an integration branch. It serves two purposes:

* Detect trivial problems that would break the upgrade tests run on the release branch (they are run at the tip of the branch, not at the latest point release)

* Do not pollute the release branch with reverted commits (because it cannot be rebased)

Let say the release to be tested is *$release* (i.e. giant for instance) and your local clone has two remotes: *origin* which is your read/write fork of the official ceph repository and *ceph* which is the read only official ceph repository.

<pre>

ceph	https://github.com/ceph/ceph.git (fetch)

ceph	https://github.com/ceph/ceph.git (push)

origin	git@github.com:dachary/ceph.git (fetch)

origin	git@github.com:dachary/ceph.git (push)

</pre>

* Create a $release-backport branch locally if it does not already exists: *git checkout -b $release-backports ceph/$release*

* Reset it to ceph/$release: *git reset --hard ceph/$release*

* Fetch all pull requests from github. Each pull request XXX has its own branch in the official ceph repository, named *pull/XXX*

** Retrieve the commits of the pull request XXX: *git fetch --force ceph +refs/pull/XXX/head:refs/remotes/ceph/pull/XXX/head*

** Merge the pull request in the local integration branch. The *--no-ff* ensures that even if the merge commit could be skipped, it will not be. *git merge --no-ff -m "$(echo -e "Merge XXX: $title\n\nReviewed-by: Myself <me@me.com>")" ceph/pull/XXX/head*

* Modify the pull requests individually to fix merge conflicts (i.e. they must merge cleanly, which may involving aggregating two pull requests into a single one designed to properly resolve the conflict). 

* Push the integration branch to github: *git push --force origin $release-backports*

* Verify the integration branch compiles and passes make check

** On the local machine: *./run-make-check.sh*

** Via the make check bot by creating a pull request with the $release-backports* integration branch

* Push the integration branch to the official repository: *git push --force ceph $release-backports* (requires write permission to the ceph repository)

The following snippet can help

<pre>

release=hammer

PRS="3963 4185"

reviewer='Loic Dachary <ldachary@redhat.com>'

git checkout -b $release-backport ceph/$release

git reset --hard ceph/$release

git fetch --force ceph $(for ref in $PRS ; do echo +refs/pull/$ref/head:refs/remotes/ceph/pull/$ref/head ; echo +refs/pull/$ref/merge:refs/remotes/ceph/pull/$ref/merge ; done)

for pr in $PRS ; do eval title=$(curl --silent https://api.github.com/repos/ceph/ceph/pulls/$pr | jq .title) ; echo $title ; git log --oneline ceph/pull/$pr/merge^1..ceph/pull/$pr/merge^2 ; git merge --no-ff -m "$(echo -e "Merge $pr: $title\n\nReviewed-by: $reviewer")" ceph/pull/$pr/head ; done

git push --force origin $release-backports

</pre>