Build only the Git branch that has been pushed to

Question

I have a Jenkins job to build the master branch of my GitHub repo. It triggers nicely when I push a commit to master, and I\'m very happy about it.

Answer 1

Found there's an whitelist config listed in Build Trigger section:

There you can specify to build/test which branch the PR will be merged into.

Answer 2

I was having the same issue so I set up a dummy project to experiment and found the solution. And found that yes, you can build only the branch that's been pushed into.

The short answer is to use a "Branch Specifier". For instance origin/feature**.

If you're using the GitFlow and all your feature branches are named with a feature/ prefix, then this is the solution.

And if you're curious here's how I figured it out.

From the repository's settings I set the service “Github plugin” with the Jenkins hook https://<jenkin server>/github-webhook/. Note that, at least for me what happened was that for some reason after pressing "test", the message of the payload being sent never changed to confirm it was received/acknowledged or anything. Maybe there’s no reply. It's confusing, but anyway...

I created a new Jenkins job and set the branch specifier to blank -which Jenkins then automatically sets to **.

I created a feature branch feature/foo and pushed into it.

• Build 1 was fired, but on the master branch.
• Build 2 was also fired on the feature/foo branch.

So it seems with the ** or blank specifier the plugin will fire builds on all branches of a repo whenever there’s a push to any of them.

Then I tried with pattern refs/heads/feature/foo and pushed another change to the feature/foo branch.

• Build 3 was fired on the feature/foo branch.
• No other builds were fired.

Sort of ok, but this is too rigid. It would force us to have one build job for each feature branch. I wanted one build job for all feature branches.

Then I tried a wildcard with pattern refs/heads/feature\*\* and pushed changes to feature/foo.

• No build was fired.

Then I tried branch specifier refs/heads/feature/\*\* and pushed.

• No build was fired

Then I saw the help of the "Branch Specifier" field reads this under the "Wildcards" section:

The syntax is of the form: REPOSITORYNAME/BRANCH. In addition, BRANCH is recognized as a shorthand of */BRANCH, * is recognized as a wildcard, and ** is recognized as wildcard that includes the separator /. Therefore, origin/branches* would match origin/branches-foo but not origin/branches/foo, while origin/branches** would match both origin/branches-foo and origin/branches/foo.

So I tried origin/feature**

• Build 4 was fired on origin/feature/foo.

Eureka! Seems you can’t use wildcards with the references (starting with refs/), but you can with the names of the actual branches (starting with origin/).

Then I created branch feature/bar and pushed to it. To verify that only this one would be built and not other branches also starting with feature/.

• Build 5 was fired on origin/feature/bar.

Looked almost there. Just needed a few more tests.

Then I pushed another change to origin/master

• No build fired. Great!

Then I pushed another change to feature/bar, to test that only this branch would be built. Despite the fact that origin/master had also been pushed into.

• Build 6 was fired on feature/bar.
• No other builds fired.

Looks good to me.

Answer 3

You can see there plugin of multiple branch configuring with Jenkins. Getting feedback for any branch from Jenkins is possible with that method.

https://wiki.jenkins-ci.org/display/JENKINS/Multi-Branch+Project+Plugin

I hope it may help.

Answer 4

you can easily specify branch in job configuration:

in section Source Code Management where you have already specified your git repository URL you have also an option to specify branches to build. Simply please a name of your branch instead of master (which is default value).

Answer 5

Actually, there seems to be an answer to precisely this question on the Jenkins GitHub plugin page :

Trigger a build when a change is pushed to GitHub

Answer 6

As @thatway_3 mentioned, this is possible with a plugin. The Multi-Branch Project Plugin that they linked to is deprecated, but you can use the Pipeline Multibranch Plugin instead.

If you install that plugin and then create a new job of type "Pipeline Multibranch", you can configure that to track a particular repository. It will then (correctly!) build all branches from there.

See also: https://jenkins.io/blog/2015/12/03/pipeline-as-code-with-multibranch-workflows-in-jenkins/

Hope this helps.