Automating CI/CD with Jenkins: A Dockerized Approach

In today's fast-paced world of software development, the need for automation in building, testing, and deploying applications is more critical than ever. Continuous Integration (CI) and Continuous Deployment (CD) pipelines play a key role in streamlining these processes. In this blog post, we'll explore a Jenkins pipeline written in Groovy that leverages Docker to automate these tasks seamlessly.

Jenkins Pipeline Overview:

Our Jenkins pipeline consists of several stages, each serving a specific purpose:

1. Code Stage:

    groovyCopy codestage('code') {
        steps {
            git url: 'https://github.com/muhammadhassanb111/node-todo-cicd.git', branch: 'master'
        }
    }
   

   In this stage, we fetch the latest code from our GitHub repository, ensuring that we're always working with the most up-to-date version of our application.

2. Build and Test Stage:

    groovyCopy codestage('build and test') {
        steps {
            script {
                echo '=== Building Docker Image ==='
                sh 'docker build . -t hassanb111/node-todo-app:latest'
                echo '=== Docker Image Built ==='
   
                echo '=== Docker Images List ==='
                sh 'docker images'
                echo '=== End of Docker Images List ==='
            }
        }
    }
   

   In this stage, we build a Docker image from our application's Dockerfile. The process is accompanied by informative messages, and we list the Docker images for visibility.

3. Login and Push Images Stage:

    groovyCopy codestage('login and push images') {
        steps {
            echo 'Logging into Docker Hub'
            withCredentials([usernamePassword(credentialsId: 'dockerhub', passwordVariable: 'dockerhubpassword', usernameVariable: 'dockerhubuser')]) {
                sh "docker login -u ${env.dockerhubuser} -p ${env.dockerhubpassword}"
                sh "docker push hassanb111/node-todo-app:latest"
            }
        }
    }
   

   This stage handles the secure login to Docker Hub using Jenkins credentials and subsequently pushes the Docker image to the Docker Hub repository.

4. Deploy Stage:

    groovyCopy codestage('deploy') {
        steps {
            script {
                echo '=== Stopping and Removing Containers ==='
                sh 'docker-compose down'
                echo '=== Containers Stopped and Removed ==='
   
                echo '=== Starting Containers ==='
                sh 'docker-compose up -d'
                echo '=== Containers Started ==='
            }
        }
    }
   

   The final stage involves stopping and removing existing Docker containers and then initiating fresh containers using Docker Compose.

   

By breaking down our CI/CD process into these stages, we ensure a systematic and automated approach to software development. This Jenkins pipeline, combined with Docker, provides a powerful foundation for building, testing, and deploying applications efficiently.