Build Docker images using Jenkins | Dockerize Java App | Automate Docker builds using Jenkins

We will learn how to automate Docker builds using Jenkins. We will use Java based application. I have already created a repo with source code + Dockerfile. The repo also have Jenkinsfile for automating the following:

- Automating builds
- Automating Docker image creation
- Automating Docker image upload
- Automating Docker container provisioning

Pre-requisites:
1. Jenkins is up and running
2. Docker installed on Jenkins instance. Click to here to know how to integrate Jenkins and Docker.
3. Docker plug-in installed in Jenkins
4. user account setup in https://cloud.docker.com

5. Port 8085 open in security firewall rules

Step #1 - Create Credentials for Docker Hub
Go to your Jenkins where you have installed Docker as well. Go to credentials -->

Click on Global credentials

Click on Add Credentials

Now Create an entry for Docker Hub credentials

Make sure you take note of the ID as circled below:

Step # 2 - Create a scripted pipeline in Jenkins, name can be anything

Step # 3 - Copy the pipeline code from below
Make sure you change red highlighted values below:
Your docker user id should be updated.
your registry credentials ID from Jenkins from step # 1 should be copied

node {
  def image
  def mvnHome = tool 'Maven3'
     stage ('checkout') {
        checkout([$class: 'GitSCM', branches: [[name: '*/master']], doGenerateSubmoduleConfigurations: false, extensions: [], submoduleCfg: [], userRemoteConfigs: [[credentialsId: '', url: 'https://bitbucket.org/ananthkannan/myawesomeangularapprepo/']]])      
        }
   
    stage ('Build') {
            sh 'mvn -f MyAwesomeApp/pom.xml clean install'           
        }
       
    stage ('archive') {
            archiveArtifacts '**/*.jar'
        }
       
    stage ('Docker Build') {
         // Build and push image with Jenkins' docker-plugin
            withDockerRegistry([credentialsId: "fa32f95a-2d3e-4c7b-8f34-11bcc0191d70", url: "https://index.docker.io/v1/"]) {
            image = docker.build("your_docker_user_id/mywebapp", "MyAwesomeApp")
            image.push()    
            }
        }

       stage('docker stop container') {
            sh 'docker ps -f name=myContainer -q | xargs --no-run-if-empty docker container stop'
            sh 'docker container ls -a -fname=myContainer -q | xargs -r docker container rm'
       }

    stage ('Docker run') {
        image.run("-p 8085:8085 --rm --name myContainer")
    }
}

Step # 4 - Click on Build to build the pipeline

Once you create the pipeline and changes values per your Docker user id and credentials ID, click on Build Now

Once build is successful, you should see stage view like below:

Steps # 5 - Access Java App which is running inside Docker container

go to browser and enter http://public_dns_name:8085

You should see page like below: