Make pipeline source available in UI and API
Description
The reason why a pipeline was created is available inside CI jobs as CI_PIPELINE_SOURCE
, but it does not seem to be possible to get it from the web interface or from API queries. This would be useful, for instance, to avoid triggering a pipeline if one has already been triggered (as opposed to a push pipeline).
When a pipeline is created through a trigger, the jobs have a "triggered" label in the build page (see https://gitlab.com/Jellby/test/pipelines/22436836/builds), but I can't find any other way to get this information.
Proposal
Expose the pipeline source in the API response, and also in the web interface. It would be nice if, in the case of triggers, the information of which trigger was used (its description) were available too.