options-directive.md

The options Directive

The options directive allows configuring Pipeline-specific options from within the Pipeline itself. We are going to add the buildDiscarder option to limit the number of logs and artifacts retained, and the skipDefaultCheckout option to skip checking out code by default in every stage. We will add both to one global options directive after the agent directive in the Jenkinsfile file in the development branch of your forked helloworld-nodejs repository.

1. Use the GitHub file editor to update the Jenkinsfile file in the development branch of your forked helloworld-nodejs repository - adding the following options directive below the agent section:

pipeline {
  agent { label 'nodejs-app' }
  options { 
    buildDiscarder(logRotator(numToKeepStr: '2'))
    skipDefaultCheckout true
  }

2. Next, we need to add an explicit checkout step - checkout scm to the Test stage, we don't want to do a checkout in any of the other stages but we do need a checkout in this stage:

    stage('Test') {
      agent { label 'nodejs-app' }
      steps {
        checkout scm
        container('nodejs') {
          echo 'Hello World!'   
          sh 'node --version'
        }
      }
    }

NOTE: The checkout scm step is outside of the container block as there is no guarantee that the nodejs container has git installed.

3. Commit Changes and then navigate to the development branch of your helloworld-nodejs job in the classic UI on your Team Master and once the job has run at least once, the job configuation will be updated to reflect what was added to the Pipeline script.

   

NOTE: A Pipeline job must run in Jenkins before any type of Pipeline directive that modifies the job configuration can take effect because there is no way for the Jenkins Master to know about it until it runs on the Jenkins Master. Also, note that for Multibranch Pipeline projects - the only way to modify much of the configuration of the managed branch specific Pipeline jobs is by doing it in the Pipeline Jenkinsfile/script as those jobs are not directly configurable from the Jenkins UI.

Finished Jenkinsfile for The options Directive

pipeline {
  agent { label 'nodejs-app' }
  options { 
    buildDiscarder(logRotator(numToKeepStr: '2'))
    skipDefaultCheckout true
  }
  stages {
    stage('Test') {
      steps {
        checkout scm
        container('nodejs') {
          echo 'Hello World!'   
          sh 'node --version'
        }
      }
    }
  }
}

You may head back to the related lab Lab 2. Stage specific agents or proceed to the main list of the labs if you like.