How to identify path/s to file/s that was/were modified in the most recent git merge in Bash or Groovy or maybe there is any other way to do that in Jenkinsfile?
A Jenkins job is triggered on every merge event.
There is a stage that should be only triggered if the most recent merge includes a new file with an arbitrary name for example: new-file.yaml in folder:
foo/env/<name-of-environment>/
or if an already existing file in that folder was modified.
To get a list of files that changed between any two commits, you could use:
git diff <commit1> <commit2> --name-only
For a merge commit, the merge commit's ID would be <commit2> and one of it's parent's commit ID would be <commit1>. Most of the time it will be the first parent of the merge commit. So for example, if the merge commit is commit X, the diff would be:
git diff X~1 X --name-only
For a trigger on a specific branch when new commits appear, you could use HEAD or @ (in most shells, including bash), so the general syntax is:
git diff @~1 @ --name-only
You could then parse the output for your desired file:
git diff @~1 @ --name-only | grep foo/env/test/
Notes:
@~1 @ will only show you changes in the top most commit, rather than all 3. If this is a possibility, you may need to save the last commit ID you ran your check on, and use that as commit1. If you always use --no-ff when merging into the target branch, it will always force a merge commit and you won't have this issue.