Jenkinsfile §

• The agent directive tells Jenkins where and how to execute the Pipeline

Simple Jenkinsfile §

pipeline {
  agent { docker { image 'maven:3.9.0-eclipse-temurijn-11' } }
  stages {
    stage('build') {
      sh 'mvn --version'
    }
  }
}

Timeout, Retry, Post Action §

pipeline {
    agent any
    stages {
        stage('Build') {
            steps {
                sh './gradlew build'
            }
        }
        stage('Sanity check') {
            steps {
                input "Continue with Deploy?"
            }
        }
        stage('Deploy') {
            steps {
                retry(3) {
                    sh './flakey-deploy.sh'
                }
 
                timeout(time: 3, unit: 'MINUTES') {
                    sh './health-check.sh'
                }
            }
        }
    }
    post {
      always {
          echo 'This will always run'
          archiveArtifacts artifacts: 'build/libs/**/*.jar', fingerprint: true
          junit 'build/reports/**/*.xml'
      }
      success {
          echo 'This will run only if successful'
          slackSend channel: '#ops-room',
            color: 'good',
            message: "The pipeline ${currentBuild.fullDisplayName} completed successfully."
      }
      failure {
          echo 'This will run only if failed'
          mail to: 'team@example.com',
            subject: "Failed Pipeline: ${currentBuild.fullDisplayName}",
            body: "Something is wrong with ${env.BUILD_URL}"
      }
      unstable {
          echo 'This will run only if the run was marked as unstable'
      }
      changed {
        echo 'This will run only if the state of the Pipeline has changed'
        echo 'For example, if the Pipeline was previously failing but is now successful'
    }
  }
}

String Interpolation §

• Jenkins uses the identical rules Groovy has for String interpolation
• These variables will be masked by Jenkins in the console output
• But Env vars in double quotes will be expandend by the shell, exposing it to operating system process listings
• So to avoid leaking credentials, use single quoted String interpolation

node {
  withCredentials([string(credentialsId: 'mytoken', variable: 'TOKEN')]) {
    sh '''
      set +x
      curl -H "Token: $TOKEN" https://some.api/
    '''
  }
}
 
/* LESS SECURE! */
node {
  withCredentials([string(credentialsId: 'mytoken', variable: 'TOKEN')]) {
    sh """
      set +x
      curl -H "Token: $TOKEN" https://some.api/
    """
  }
}