Jenkins: A Declarative Pipeline

Jenkins remains widely used for self-hosted CI/CD. Put the pipeline in a Jenkinsfile in the repository so it is versioned and reviewed like code.

pipeline {
  agent any
  options { timeout(time: 20, unit: 'MINUTES') }
  stages {
    stage('Build') {
      steps { sh 'npm ci' }
    }
    stage('Test') {
      steps { sh 'npm test' }
    }
    stage('Package') {
      when { branch 'main' }
      steps { sh 'docker build -t registry.example.com/app:${BUILD_NUMBER} .' }
    }
  }
  post { failure { echo 'Build failed' } }
}

Tips:

• Run Jenkins on Java 11 (Java 17 is supported from the 2.346 LTS line).
• Use Credentials for secrets, never plain text in the file.
• Use agents or containers for builds instead of running work on the controller.
• Keep plugins few and updated, and back up JENKINS_HOME.