[FIXED] Trigger jenkins build if only a specific file is changed

Issue

I have my codebase in GIT. There are 5 files in the code base i.e.

• File1
• File2
• File3
• File4
• File5

I want to trigger a jenkins build only if File 2 is changed.Please note that, post the build is triggered it should pull the entire codebase.

I tried using poll SCM, but the problem is that the build gets triggered if any of the files in the repository are changed.I want to trigger it only if File 2 changes.

Is it possible?

Solution

Here's how I would do it.

1. Configure your Jenkins job to Trigger builds remotely.

This enables a build trigger URL in the form of JENKINS_URL/job/MYJOB/build?token=TOKEN_NAME. You have to specify the token name yourself.

2. Configure a git post-receive hook on your repo to call that trigger.

The script for the hook is usually under .git/hooks/post-receive. The post-receive hook runs after the entire process is completed and can be used to update other services or notify users.

A post-receive hook gets its arguments from stdin, in the form <oldrev> <newrev> <refname>.

You can retrieve the file list from the new HEAD commit and then only proceed to the next step if it includes File2. Something like this (not tested):

#!/bin/bash
while read oldrev newrev refname
do
    # list of changed files for a commit
    filelist=$(git diff-tree --no-commit-id --name-only -r $newrev)
    if [[ $filelist == *"File2"* ]]; then
        # call the URL according to your build trigger config
    fi
done

More details on git hooks.

Answered By - Martin