Handle specific ref name during api calls for mr pipelines from project with merge results/trains enabled

[tidalf]

This fixes this issue #280 for our setup.

Not sure it's fine as is, or if it'd be better to try to retrieve the settings of the project.

[Art3mK]

@mvisonneau any chance for this to be merged? 🙏 I have the same problem, latest gcpe image can't find MR pipeline for the repo with merge trains enabled. Works fine for repos without merge trains.

[kalw]

Yes ! Would be lovely if @mvisonneau can have a look :)

[mj3c]

I've just been battling with this issue for quite a while and stumbled into this PR. So this proposal would work for all MRs that have at least 1 regular MR pipeline and 1 MR results pipeline. There's a regex which filters the discovered refs before execution ever reaches the changes in this proposal. Here it is:

gitlab-ci-pipelines-exporter/pkg/schemas/ref.go

Line 13 in 0687efd

mergeRequestRegexp string = `^((\d+)|refs/merge-requests/(\d+)/head)$`

This means that only MR refs with /head (regular MR pipelines) are considered. Meaning that if you have enabled MR result pipelines, all the refs will be /merge (with the exception of when there are conflicts, as stated in gitlab docs, search for "conflict").

Here's a git patch in another thread that works for us. This one ensures that both the regular MR pipelines and MR results pipelines are gathered and exported: #534 (comment)

[sebglon]

We have the same issue and want to use this Fix.
have you plan to merge it?

[tolikkostin]

Any updates? I would like to collect metrics for train MRs too