Trigger a jenkins job by a github pull request
Clone this repo and follow the steps

Run the Jenkins server: 
    1 - docker-compose up
    2 - get the password from the console to login
    3 - install recommanded plugins and create an admin user account

Configure Jenkins and create a job:
    1 - Install the plugin: "GitHub Pull Request Builder" & "Docker pipelines"
    2 - Create a new pipeline job
    3 - Check and configure: General\Github with the HTTPS URL
    4 - Build Triggers\GitHub Pull Request Builder  -  Use "Personal access tokens" from github as credentials (https://github.com/settings/tokens). Check "Use github hooks for build triggering" 
    5 - Pipeline\Pipeline script from SCM 
    6 - Refspec: +refs/pull/*:refs/remotes/origin/pr/*
    7 - Branches to build\Branch specifier - ${sha1}
    8 - Uncheck "lightweight checkout" 

Configure Github webhook:
    1 - https://github.com/AndreiBrandes/jenkins/settings/hooks 
    2 - URL: http://ip:8080/ghprbhook/
    3 - Content type: Json
    4 - Select events: "Pull requests" 
    5 - Check the active box and watch the icon turn green after applying