Allow users to choose a branch pipeline merge strategy

Release notes

Problem to solve

In order to address a race condition mentioned in #384927 (closed) we can provide the ability to configure the strategies they can choose for branch pipelines ( #384927 (comment 1699500230))

Proposal

1. The users can choose which branch pipelines should be considered (CI_PIPELINE_SOURCE)

2. For each source

We might also need to consider up to four levels of strictness per source, i.e. all four combinations of "must be created" and "must succeed":

• must be created and must succeed
• must be created but allowed to fail
• optional but must succeed if created
• optional and allowed to fail

Intended users

Feature Usage Metrics

Does this feature require an audit event?

This page may contain information related to upcoming products, features and functionality. It is important to note that the information presented is for informational purposes only, so please do not rely on the information for purchasing or planning purposes. Just like with all projects, the items mentioned on the page are subject to change or delay, and the development, release, and timing of any products, features, or functionality remain at the sole discretion of GitLab Inc.

This page may contain information related to upcoming products, features and functionality. It is important to note that the information presented is for informational purposes only, so please do not rely on the information for purchasing or planning purposes. Just like with all projects, the items mentioned on the page are subject to change or delay, and the development, release, and timing of any products, features, or functionality remain at the sole discretion of GitLab Inc.