Fetch the number of unreleased commits on the active stable branches
As part of extending the maintenance policy, the metric to measure the patch release pressure will be updated to use unreleased commits. These commits are the ones that have been merged into stable branches but haven't been included in any tag. To get this information, we need a new service that returns the number of unreleased commits in each stable branch.
A service should be implemented on release-tools that:
- Compares the stable branches against the last tag associated with the version using the Compare API.
- Return the number of unreleased commits, see an example here #2656 (comment 1164586312)
- Consider the stable branches associated with the versions included in the new maintenance policy. At the moment of writing this issue (2022-11-10) they are be:
15-5-stable-ee
,15-4-stable-ee
and15-3-stable-ee
- Get the unreleased commits for components under the Managed versioning (GitLab, Omnibus, CNG, and Gitaly)
- Be flexible enough to compare any new component that joins the managed versioning model.