Introduction To CI/CD

CI/CD stands for Continuous Integration & Continuous Delivery. It refers to the process of automating the building, testing, releasing, and deploying of software. This methodology integrates new code from development to production seamlessly.

In Agile teams adopting DevOps culture, automating these processes is essential to enhance agility. CI/CD has gained prominence with the rise of DevOps practices.

How Does the CI/CD Pipeline Work?

As deployment needs become more frequent, it’s crucial to ensure that security checks, code tests, health checks, and functionality validations are automated. These processes should be efficient, minimizing downtime and ensuring that end-users remain unaffected during deployments.

Terminology

• CI (Continuous Integration): Focuses on merging developers’ work into a shared repository frequently, facilitating early detection of integration issues and promoting collaborative development.

• CD (Continuous Delivery): Aims to expedite the deployment process by automating each step, ensuring safe and rapid releases.

• Pipeline: A series of automated steps that build, test, and deploy applications, forming the backbone of the deployment process.

Setting Up a CI/CD Pipeline with Jenkins

In this example, we’ll use Jenkins, an open-source automation server that enables developers to reliably build, test, and deploy their software.

Installation

To install Jenkins, follow the official installation guide: Jenkins Installation

Pipeline Configuration

You can specify an agent where the pipeline will run, such as a Kubernetes pod, Docker container, or the server hosting Jenkins. For more information, refer to the Jenkins Agents Documentation.

Additionally, you can define pipeline-specific configurations using options and set up post actions for notifications or triggering other jobs. Detailed information is available in the Jenkins Pipeline Syntax.

Here’s an example of a basic Jenkins pipeline:

pipeline {
    agent {
        docker {
            image 'maven:3-alpine'
            args '-v /root/.m2:/root/.m2'
        }
    }
    options {
        skipStagesAfterUnstable()
    }
    stages {
        stage('Build') {
            steps {
                sh 'mvn -B -DskipTests clean package'
            }
        }
        stage('Test') {
            steps {
                sh 'mvn test'
            }
            post {
                always {
                    junit 'target/surefire-reports/*.xml'
                }
            }
        }
        stage('Deliver') {
            steps {
                sh './jenkins/scripts/deliver.sh'
            }
        }
    }
}

In this pipeline:

• Agent: Specifies a Docker container with Maven for building the project.

• Stages: Defines three stages—Build, Test, and Deliver.

  • Build Stage: Compiles the project and packages it, skipping tests.

  • Test Stage: Runs the tests and publishes the results.

  • Deliver Stage: Executes a delivery script.

This setup provides a foundational CI/CD pipeline. You can extend it with additional steps and configurations as needed.

For more detailed information on CI/CD, refer to the Wikipedia article on CI/CD.

If you have any questions or need further assistance, feel free to leave a comment.