How to get the Generic Webhook Trigger Plugin to work with multibranch pipelines in Jenkins?

Question

I'm trying to set up a scenario where a pull request is created on github that triggers a Jenkins multibranch pipeline, and where that multibranch pipeline uses the Generic Webhook Plugin to extract values from the POST request sent from github to jenkins to be used in the script.

Unfortunately, as described on the Generic Webhook Trigger Plugin wiki:

Note: When configuring from pipeline, that pipeline needs to run once, to apply the plugin trigger config, and after that this plugin will be able to trigger the job. This is how Jenkins works, not something implemented in this plugin. You can avoid this by using Job DSL and have Job DSL create pipeline jobs with the plugin configured in that DSL.

This would be OK using a normal pipeline since it would just be a one off on creation of the Jenkins job. The problem however is that a multibranch pipeline will create a new job whenever a new branch/PR is created, and that means that for each pull request I create on github (which triggers my multibranch pipeline script), I have to then run it twice to get the generic webhook functionality working. Having to resubmit for each PR would be tedious for long-run projects.

It seems to me like there are two possible approaches to solving/improving on this problem. One is to try and play around with DSL Jobs (as suggested by the wiki); but I tried this and couldn't get it to work (it was adding a huge amount of complexity to the set up, so I've abandoned it for now).

The second possible solution is as follows: when a PR is created in github, the Generic Webhook will cause a new job to be created in the multibranch pipeline corresponding to that PR; the first time the multibranch pipeline runs the first build of this newly created job will fail for the reason given in the quote above; but then a solution might involve testing that the first job failed and somehow telling Jenkins to try rebuilding for that job again.

So my question relates to this second approach: how can I most neatly run a rebuild for this multibranch pipeline upon the creation of a PR on github?

Any advice/suggestions would be appreciated!

Answer 1

For triggering multibranch pipline by webhook you can use this plugin:
"Multibranch Scan Webhook Trigger" https://plugins.jenkins.io/multibranch-scan-webhook-trigger/

Answer 2

Actually that is not true for multibranch pipelines . Just ordinary pipelines needs to run twice.

I updated the docs like:

When configuring from pipeline (not multibranch pipeline)...