[Mesa-dev] Merge bot ("Marge") enabled

[Michel Dänzer]

On 2019-12-13 10:35 p.m., Eric Anholt wrote:
> I finally got back around to experimenting with the gitlab merge bot,
> and it turns out that the day I spent a few weeks back I had actually
> given up 5 minutes before the finish line.
> 
> Marge is now enabled for mesa/mesa, piglit, and parallel-deqp-runner.
> How you interact with marge:
> 
> - Collect your reviews
> - Put reviewed-by tags in your commits
> - When you would have clicked "Merge when pipeline succeeds" (or,
> worse, rebase and then merge when pipeline succeeds), instead edit the
> assignee of the MR (top right panel of the UI) and assign to Marge Bot
> - Marge will eventually take your MR, rebase it and let the pipeline run.
> - If the pipeline passes, Marge will merge it
> - If the pipeline fails, Marge will note it in the logs and unassign
> herself (so your next push with a "fix" won't get auto-merged until
> you decide to again).
> 
> In the commit logs of the commits that Marge rebased (they'll always
> be rebased), you'll get:
> 
> Part-of: <https://gitlab.freedesktop.org/anholt/gitlab-experiments/merge_requests/3>
> 
> In the final commit of that MR, you'll get:
> 
> Tested-by: Marge Bot
> <https://gitlab.freedesktop.org/anholt/gitlab-experiments/merge_requests/3>
> 
> I feel like this is a major improvement to our workflow, in terms of
> linking commits directly to their discussions without indirecting
> through google.

Thanks for setting this up! I think it'll make merging MRs a lot less
painful, and as a bonus make the pipeline finish more quickly on average
(by avoiding useless pipeline runs).


> Note that one Marge instance will only process one MR at a time, so we
> could end up backed up.  There's a mode that will form merge trains,
> but I don't understand that mode enough yet to trust it. I think for
> Mesa at this point this is going to be fine, as we should still be
> able to push tens of MRs through per day.

Yeah, I think we're a pretty long way from that becoming an issue.
Looking at https://gitlab.freedesktop.org/mesa/mesa/pipelines/charts ,
we've had a pretty constant rate of ~10-15 MRs being merged on average
per day this year, and currently the pipeline takes ~20 minutes on
average, allowing up to ~70 MRs to be merged per day.


-- 
Earthling Michel Dänzer               |               https://redhat.com
Libre software enthusiast             |             Mesa and X developer