Merge Train Development Documentation
Everyone can contribute. Help move this issue forward while earning points, leveling up and collecting rewards.
Problem to Solve
Merge trains has a high level of complexity and requires cross functional collaboration as it builds on the components of the Pipeline Execution and Source Code and Code Review and Gitaly groups. It was also historically built by 1 developer and not changed much since leading to historic lack of domain knowledge in the maintaining team.
We have development documentation for the Category:Continuous Integration feature category but not the Category:Merge Trains feature category.
There is a technical handoff google doc from the original developer that may not be easy for folks to find and is not fully representative of the merge train flow.
Proposal
Add documentation including an architectural diagram to the official development docs as we have for the CI category.
WIP diagram: https://app.diagrams.net/#G1LuHHddiVUXk-1Skp0Bh5dqWaO-tEa845 (better as mermaid since it is more likely to be updated as the code changes)