Issue

How to make GitHub trigger Freestyle jobs or Pipelines in Jenkins.

In the Job configuration, one of the following Build Triggers needs to be selected :

For Freestyle jobs
- For PUSH events: GitHub hook trigger for GITScm polling (in the past named as Build when a change is pushed to GitHub) by GitHub plugin
- For PULL REQUEST events: Build pull requests to the repository by CloudBees GitHub Pull Request Builder plugin
For Pipeline jobs
- Just PUSH events: GitHub hook trigger for GITScm polling (in the past named as Build when a change is pushed to GitHub) by GitHub plugin
- JENKINS-35132
  - The job has to be executed manually one time in order for the push trigger and the git repo to be registered
  - Example of Jenkinsfile (Note that it includes GitHub hook trigger for GITScm polling enabled)
```
properties([pipelineTriggers([githubPush()])])

node {
    stage ('Checkout'){
        git branch: 'exampleBranch', url: 'https://github.com/example-org/example-repo.git'
    }
    stage ('Build'){
        // steps
    }
    stage ('Test'){
        // steps
    }
}    
```

Notes:
1. CloudBees GitHub Pull Request Builder plugin plugin requires Enable Git validated merge support enabled.
2. Both triggers can be selected together if it was needed in a Freestyle project. However Build pull requests to the repository trigger option is not available for Pipeline jobs. As a workaround, use Multibranch Pipeline and restrict the branch to build in Advanced options > Include branches to just the master (a Jenkinsfile in the master branch of the repo is needed).

IMPORTANT: If Manage hooks is enabled (Automatic mode) webhooks are generated after you Save the configuration of the job with the right triggers.