linking PRs -> Releases -> PRs

[jstrachan]

it would be awesome to be able to track in the git provider a PR being created to it being merged & a release to then triggering a downstream PR in another repository and so forth.

Then if you have a bunch of related repositories you could use the tracing to see how long it takes for changes to make it across multiple repositories

I wonder if we need to come up with a canonical comment string we can use on a Pull Request to indicate where it came from and maybe associated issue/trace ID using a standard comment format? I can see it being useful both at just joining the git information (e.g. when did a fix 123 in repo A make it into a release of repo B or C?) as well as the tracing/timings (how long for a PR in A to be released in C).

commenting with the Pull Request/Changelog on downstream Pull Request/Changelogs is a nice easy way to get linking in both directions within git comments too

cc @vbehar

[vbehar]

yes exactly, if the promotion PR is created with the changelog of the release in the PR body, then it's easy to update the lighthouse-telemetry-plugin to react on new PR, parse the body, and for each "source" PR, extract the traceparent from the comments. We can then create a new span for the new PR, and store the spancontext in a new PR comment.

I'll have a look at it after my vacation, because in our setup we're already creating promotion PRs with the release changelog in the PR body ;-)

I guess that's "gitops observability" ;-)

[vbehar]

another thing we can do, is to add the notion of "parent PR" in the pull requests in the CD Indicators app, so that we can build indicators for the whole workflow