jenkins

# Jenkins ## What I Do I provide expertise in Jenkins - the widely-used open-source automation server that enables building, testing, deploying, and automating software delivery pipelines. I cover pipeline as code, distributed builds with agents, plugin ecosystem management, integration with cloud services, and advanced automation patterns. Jenkins provides flexible automation for any technology stack and deployment target. ## When to Use Me - Building comprehensive CI/CD pipelines for application delivery - Orchestrating complex multi-stage build and deployment workflows - Managing distributed build infrastructure with Jenkins agents - Integrating with version control, artifact repositories, and cloud platforms - Automating testing, security scanning, and code quality gates - Implementing blue-green or canary deployment strategies - Building container images and deploying to Kubernetes - Managing infrastructure as code with Terraform and Ansible - Setting up automated code reviews and merge request pipelines ## Core Concepts - **Jenkins Pipeline**: Workflow definitions as code using declarative or scripted syntax - **Jenkinsfile**: Version-controlled pipeline definitions alongside application code - **Distributed Builds**: Master-agent architecture for scaling build capacity - **Blue Ocean**: Modern UI for visualizing and managing pipelines - **Shared Libraries**: Reusable pipeline components across multiple projects - **Stages and Steps**: Pipeline structure with sequential and parallel execution - **Agent Nodes**: Build executors running on dedicated infrastructure - **Build Triggers**: Automated pipeline execution based on events or schedules - **Artifact Management**: Storing and versioning build outputs - **Plugin Ecosystem**: Extending Jenkins capabilities with community plugins - **Credentials Management**: Secure storage for API keys, passwords, and certificates - **Parameterization**: Dynamic inputs controlling pipeline execution - **Environment Variables**: Configuration and context for pipeline steps - **Declarative vs Scripted**: Two pipeline syntaxes with different use cases - **Post Actions**: Cleanup, notifications, and actions after pipeline completion ## Code Examples ### Declarative Pipeline with Stages ```groovy pipeline { agent { docker { image 'maven:3.9-eclipse-temurin-17' args '-v $HOME/.m2:/root/.m2' } } environment { APP_NAME = 'order-service' APP_VERSION = '1.0.0' DOCKER_REGISTRY = 'registry.example.com' SONAR_URL = 'sonar.example.com' ARTIFACTORY_URL = 'artifactory.example.com' } options { timeout(time: 30, unit: 'MINUTES') disableConcurrentBuilds() buildDiscarder(logRotator(numToKeepStr: '10')) timestamps() } stages { stage('Checkout') { steps { checkout scm script { currentBuild.displayName = "${APP_VERSION}-${BUILD_NUMBER}" } } } stage('Initialize') { steps { sh 'mvn clean compile -DskipTests -q' sh 'mvn dependency:tree -q' stash name: 'source', includes: '**/*.java' } } stage('Test') { parallel { stage('Unit Tests') { agent any steps { unstash 'source' sh 'mvn test -Dsurefire.failIfNoSpecifiedTests=false' junit '**/target/surefire-reports/*.xml' } post { always { coverage qualityGates: [[threshold: 50, metric: 'LINE']], sourceEncoding: 'UTF-8' } } } stage('Integration Tests') { agent { docker { image 'postgres:15-alpine' reuseNode true } } environment { DATABASE_URL = 'jdbc:postgresql://localhost:5432/testdb' DB_PASSWORD = credentials('test-db-password') } steps { sh 'mvn verify -Pintegration-test' junit '**/target/failsafe-reports/*.xml' } } } } stage('Static Analysis') { steps { withSonarQubeEnv('SonarQube') { sh 'mvn sonar:sonar \ -Dsonar.projectKey=${APP_NAME} \ -Dsonar.java.binaries=. \ -Dsonar.coverage.jacoco.xmlReportPaths=**/target/site/jacoco/jacoco.xml' } } post { always { recordIssues( tools: [java(), javaDoc(), spotBugs()], qualityGates: [[threshold: 1, type: 'NEW', defaultEncoding: 'UTF-8']] ) } } } stage('Build') { steps { sh 'mvn package -DskipTests -q' stash name: 'artifact', includes: '**/target/*.jar' } } stage('Security Scan') { agent { label 'security' } steps { unstash 'artifact' dependencyCheck additionalArguments: ''' -o ./reports/ -f HTML --suppression ./security/suppressions.xml ''', odcInstallation: 'dependency-check' dependencyCheckPublisher pattern: '**/*dependency-check-report.xml' openVASParse pattern: '**/*openvas-report.xml' } } stage('Docker Build') { steps { unstash 'artifact' script { dockerImage = docker.build("${DOCKER_REGISTRY}/${APP_NAME}:${APP_VERSION}", '.') } } } stage('Push Image') { steps { script { docker.withRegistry("https://${DOCKER_REGISTRY}", 'docker-registry-credentials') { dockerImage.push("${APP_VERSION}") dockerImage.push('latest') } } } } stage('Deploy to Staging') { when { branch 'main' } steps { kubernetesDeploy( kubeconfigId: 'kubeconfig-staging', configs: 'k8s/staging/*.yaml', enableConfigSubstitution: true ) input message: 'Deploy to Production?', ok: 'Deploy' } } stage('Deploy to Production') { when { branch 'main' } steps { script { kubernetesDeploy( kubeconfigId: 'kubeconfig-production', configs: 'k8s/production/*.yaml', enableConfigSubstitution: true ) deployAndVerify( environment: 'production', serviceName: "${APP_NAME}", imageTag: "${APP_VERSION}" ) } } } } post { success { archiveArtifacts artifacts: '**/target/*.jar', fingerprint: true emailext( subject: "Build Success: ${currentBuild.fullDisplayName}", body: "Build completed successfully", recipientProviders: [[$class: 'RequesterRecipientProvider']] ) } failure { emailext( subject: "Build Failed: ${currentBuild.fullDisplayName}", body: "Build failed. Check logs: ${BUILD_URL}", recipientProviders: [[$class: 'RequesterRecipientProvider']] ) } unstable { archiveArtifacts artifacts: '**/target/*.jar', allowEmptyArchive: true } always { cleanWs() } } } ``` ### Shared Library for Deployments ```groovy // vars/deployToKubernetes.groovy def call(Map config) { def namespace = config.namespace ?: 'default' def manifests = config.manifests ?: 'k8s/*.yaml' def timeout = config.timeout ?: 300 timeout(time: timeout, unit: 'SECONDS') { stage("Deploy to ${namespace}") { withKubeConfig([credentialsId: config.kubeconfigId]) { sh """ kubectl apply -f ${manifests} -n ${namespace} kubectl rollout status deployment/${config.app} -n ${namespace} --timeout=${timeout}s """ } } } } // vars/sonarqubeAnalysis.groovy def call(Map config = [:]) { def qualityGate = config.qualityGate ?: true stage('SonarQube Analysis') { withSonarQubeEnv(config.sonarName ?: 'SonarQube') { sh "mvn sonar:sonar \ -Dsonar.projectKey=${env.APP_NAME} \ -Dsonar.projectVersion=${env.APP_VERSION} \ -Dsonar.java.source=17 \ -Dsonar.java.binaries=target/classes" } } if (qualityGate) { stage('Quality Gate') { timeout(time: 15, unit: 'MINUTES') { def qg = waitForQualityGate() if (qg.status != 'OK') { unstable("Quality Gate failed: ${qg.status}") } } } } } // vars/notifyTeams.groovy def call(Map config) { def webhookUrl = config.webhookUrl ?: '' def status = currentBuild.currentResult def color = status == 'SUCCESS' ? '2DC76D' : 'D93F3F' if (webhookUrl) { httpRequest( url: webhookUrl, httpMode: 'POST', contentType: 'APPLICATION_JSON', requestBody: """ { "@type": "MessageCard", "@context": "http://schema.org/extensions", "themeColor": "${color}", "summary": "${config.title ?: env.JOB_NAME} - ${status}", "sections": [{ "activityTitle": "${config.title ?: env.JOB_NAME}", "activitySubtitle": "${env.JOB_NAME} #${env.BUILD_NUMBER}", "activityImage": "https://jenkins.example.com/logo.png", "facts": [ {"name": "Status", "value": "${status}"}, {"name": "Duration", "value": "${currentBuild.durationString}"} ], "markdown": true, "text": "${config.message ?: "Build ${status}"}" }], "potentialAction": [{ "@type": "OpenUri", "name": "View Build", "targets": [{"os": "default", "uri": "${env.BUILD_URL}"}] }] } """ ) } } ``` ### Scripted Pipeline with Complex Logic ```groovy node('master') { stage('Prepare') { checkout scm def props = readProperties file: 'version.properties' env.APP_VERSION = props.version env.RELEASE_BRANCH = "release/v${env.APP_VERSION}" } if (env.CHANGE_ID) { stage('Pull Request Build') { withCredentials([string(credentialsId: 'github-token', variable: 'GITHUB_TOKEN')]) { sh """ gh pr status --json state,number if [[ \$(gh pr status --json state --jq '.[] | select(.state == "MERGED")') ]]; then echo "PR already merged, skipping" fi """ } } } def shouldDeploy = false stage('Test') { parallel ( 'Unit Tests': { sh 'mvn test -Dtest=*Test' }, 'Integration Tests': { sh 'mvn verify -Pintegration -DskipUnitTests' } ) shouldDeploy = currentBuild.result == 'SUCCESS' } if (shouldDeploy && env.BRANCH_NAME == 'main') { stage('Create Release Branch') { withCredentials([string(credentialsId: 'github-token', variable: 'GITHUB_TOKEN')]) { sh """ git checkout -b ${RELEASE_BRANCH} sed -i "s/version=.*/version=${APP_VERSION}/" version.properties git add . git commit -m "Bump version to ${APP_VERSION}" git push origin ${RELEASE_BRANCH} gh pr create --title "Release ${APP_VERSION}" --body "Release branch for v${APP_VERSION}" """ } } } stage('Cleanup') { cleanWs() } } ``` ### Jenkins Configuration as Code ```yaml # jenkins.yaml jenkins: systemMessage: "Welcome to Jenkins - CI/CD Platform" numExecutors: 5 primaryView: all: name: "all" views: - all mode: NORMAL securityRealm: ldap: configurations: - server: "ldap.example.com" rootDN: "dc=example,dc=com" userSearchBase: "ou=users" userSearchFilter: "uid={0}" groupSearchBase: "ou=groups" groupSearchFilter: "" disableMailAddressResolver: false displayNameAttributeName: "displayName" mailAddressAttributeName: "mail" cache: size: 100 ttl: 10 userIdStrategy: CaseInsensitive groupIdStrategy: CaseInsensitive authorizationStrategy: globalMatrix: permissions: - "Overall/Administer:admin-group" - "Overall/Read:authenticated" - "Job/Read:authenticated" - "Job/Build:authenticated" - "Job/Discover:authenticated" - "Run/Update:authenticated" crumbIssuer: standard: enableSecurity: true