Jenkins

Introduction

Jenkins is the leading open-source automation server, used to build, test, and deploy software through pipelines defined as code (Jenkinsfile). With over 1,800 community-contributed plugins, it integrates with virtually any version control system, build tool, and deployment target, and supports distributed builds across heterogeneous agent fleets.

How to Install

Starting via Binary

Quick Start

# download and decompression
# https://www.jenkins.io/download/
wget https://get.jenkins.io/war-stable/2.401.1/jenkins.war

# run and init password
mkdir /opt/jenkins-config
JENKINS_HOME=/opt/jenkins-config java -jar jenkins.war
cat /opt/jenkins-config/secrets/initialAdminPassword


# On Ubuntu
# https://www.jenkins.io/doc/book/installing/linux/#debianubuntu

Starting via Docker

# create bridge network
docker network create jenkins

# run
docker run -d -v jenkins_home:/var/jenkins_home -p 8080:8080 -p 50000:50000 --restart=on-failure jenkins/jenkins:lts-jdk11 --name jenkins
# persistence storage info and init password
docker inspect jenkins_home
...
cat /var/lib/docker/volumes/jenkins_home/_data/secrets/initialAdminPassword

Starting via Kubernetes

# Add and update repo
helm repo add jenkinsci https://charts.jenkins.io
helm repo update

# Get charts package
helm pull jenkinsci/jenkins --untar
cd jenkins

# Configure and install
vim values.yaml
helm -n cicd install jenkins . --create-namespace

# Get password
kubectl -n cicd get secrets jenkins -ojsonpath='{.data.jenkins-admin-password}' |base64 -d

Pipeline Example

Jenkinsfile with Kubernetes agent:

pipeline {
    agent {
        kubernetes {
            defaultContainer 'jnlp'
        }
    }

    stages {
        stage('Build') {
            steps {
                container('maven') {
                    sh 'mvn clean package'
                }
            }
        }
        stage('Deploy') {
            steps {
                container('kubectl') {
                    sh 'kubectl apply -f deployment.yaml'
                }
            }
        }
    }
}

Reference:

1. Official Website
2. Repository