Automate Docker builds using Jenkins Pipelines | Dockerize Python App | Upload Docker Images into AWS ECR

We will learn how to automate Docker builds using Jenkins. We will use Python based application. I have already created a repo with source code + Dockerfile. We will see how to create Docker image and upload into AWS ECR successfully. We will not be using AWS access keys to upload image into ECR, we will be using IAM role and attach to Jenkins instance to access ECR.

- Automating builds
- Automating Docker image builds
- Automating Docker image upload into AWS ECR
- Automating Docker container provisioning

 

Watch here for YouTube channel:
 

Pre-requisites:

1. Jenkins is up and running
2. Docker installed on Jenkins instance. Click here to for integrating Docker and Jenkins
3. Docker and Docker pipelines plug-in are installed
4. Repo created in ECR, Click here to know how to do that.
5. Make sure port 8096 is opened up in firewall rules. 

6. Create an IAM role with AmazonEC2ContainerRegistryFullAccess policy, attach role to Jenkins EC2 instance

7. Make sure AWS cli is installed in Jenkins instance.

Code for this video is here:

Make sure you fork my repo https://github.com/akannan1087/myPythonDockerRepo

and make changes in the pipeline accordingly.

Step # 1 - Create a pipeline in Jenkins, name can be anything

Step # 2 - Copy the pipeline code from below
Make sure you change red highlighted values below:
Your account_d should be updated and repo should be updated.

pipeline {
    agent any
    environment {
        registry = "acct_id.dkr.ecr.us-east-1.amazonaws.com/your_ecr_repo"
    }
   
    stages {
        stage('Cloning Git') {
            steps {
                checkout([$class: 'GitSCM', branches: [[name: '*/master']], doGenerateSubmoduleConfigurations: false, extensions: [], submoduleCfg: [], userRemoteConfigs: [[credentialsId: '', url: 'https://github.com/akannan1087/myPythonDockerRepo']]])     
            }
        }
  
    // Building Docker images
    stage('Building image') {
      steps{
        script {
          dockerImage = docker.build registry
        }
      }
    }
   
    // Uploading Docker images into AWS ECR

    stage('Pushing to ECR') {
     steps{  
         script {
                sh 'aws ecr get-login-password --region us-east-1 | docker login --username AWS --password-stdin acct_id.dkr.ecr.us-east-1.amazonaws.com'
                sh 'docker push acct_id.dkr.ecr.us-east-1.amazonaws.com/your_ecr_repo:latest'
         }
        }
      }
   
         // Stopping Docker containers for cleaner Docker run
     stage('stop previous containers') {
         steps {
            sh 'docker ps -f name=mypythonContainer -q | xargs --no-run-if-empty docker container stop'
            sh 'docker container ls -a -fname=mypythonContainer -q | xargs -r docker container rm'
         }
       }
      
    stage('Docker Run') {
     steps{
         script {
                sh 'docker run -d -p 8096:5000 --rm --name mypythonContainer acct_id.dkr.ecr.us-east-1.amazonaws.com/your_ecr_repo:latest'
            }
      }
    }
    }
}

Step # 3 - Click on Build - Build the pipeline

Once you create the pipeline and changes values per your ECR account ID, click on Build now.

Steps # 4 - Check Docker images are uploaded into ECR

Login to ECR, click on your repo, now you should see the image got uploaded.

Steps # 5 - Access PythonApp in the browser which is running inside docker container

Once build is successful, go to browser and enter http://public_dns_name:8096

You should see page like below:

How to create an Elastic IP Address in AWS and assign to your EC2 instance | Associate Elastic IP address to EC2 instance

Elastic IP address is static IP address provided by AWS, you should avoid using public ip address as it changes every stop/start of EC2 instance.
How to create Elastic IP address:

Go to AWS console, Click on EC2, Elastic IPs.

Click on Allocate Elastic IP address

Now it should create Elastic IP address.

Click on Actions, Associate Elastic IP address and choose your instance from Instances textbox and pick up the Private ip address automatically.

That's it! Elastic IP(static) address have been assigned to your EC2 instance.

How to clean workspace after Jenkins Build - Clean up workspace after every build

You can clean workspace using Workspace cleanup plugin in Jenkins after builds executions.

Install workspace clean up Plug-in

Free Style Job Workspace - cleanup

Go to your existing freestyle job, click on Post-Build actions --> Select Delete workspace when build is done option.

Now run the job. You should be able to see workspace is cleaned up after build is done inside Jenkins node. You will not see any folder with job name, in Ubuntu usually under /var/lib/jenkins/workspace/

Pipeline Job Workspace - cleanup code

Go to your existing pipeline job, you can code something like this below:
pipeline {
    agent any
     tools {
        maven 'Maven3'
    }
    stages {
        stage ("checkout")  {
            steps {
            checkout logic here
            }
        }
    stage ('build')  {
        steps {
            sh "mvn clean install -f MyWebApp/pom.xml"
        }
     }
    }

/*** workspace clean up*/
    post {
        always {
            cleanWs()
        }
    }   
 }

Watch this on YouTube video: