Jenkins Tutorial: Setup and CI/CD Pipeline

Introduction

As a software developer, one of the most crucial tools in your DevOps arsenal is Jenkins. Jenkins is an open-source automation server that facilitates continuous integration and continuous delivery (CI/CD) processes. In this blog, we will take you on a journey from the basics of Jenkins to setting it up and finally building your first CI/CD pipeline.

Why Jenkins?

Jenkins has become the go-to choice for automating repetitive tasks, testing, and deploying code. Its extensibility and flexibility make it a popular choice for teams of all sizes. So, let's dive right in and get started with Jenkins.

Setting up Jenkins

Step 1: Prerequisites

Before we dive into Jenkins, ensure that you have the following prerequisites in place:

A server (or virtual machine) running a Linux distribution (e.g., Ubuntu).
Java Development Kit (JDK) installed.
Administrative access to the server.

Step 2: Jenkins Installation

Ubuntu:

Update your package list:
```
 sudo apt update
```
Install Jenkins and its dependencies:
```
 sudo apt install -y jenkins
```
Start the Jenkins service:
```
 sudo systemctl start jenkins
```
Enable Jenkins to start on boot:
```
 sudo systemctl enable jenkins
```

Retrieve the Jenkins initial password:

 sudo cat /var/lib/jenkins/secrets/initialAdminPassword

Open a web browser and navigate to http://your_server_ip_or_domain:8080. Enter the initial password and follow the setup wizard.

Other Linux Distributions:

You can find installation instructions for various distributions on the official Jenkins documentation.

Step 3: Jenkins Plugins

Jenkins provides a vast ecosystem of plugins to extend its functionality. Install the necessary plugins for your project. Some commonly used ones include:

Git Plugin
Docker Plugin
AWS SDK (v3)
Node.js Plugin

Step 4: Basic Configuration

Configure Jenkins with essential settings, such as global environment variables, security options, and email notifications, according to your project's requirements.

Step 5: Create a Jenkins Job

Click on "New Item" to create a new Jenkins job.
Choose the "Freestyle project" or "Pipeline" option depending on your project's needs.
Configure the job with the necessary build steps and triggers.

Step 6: Build and Test

Execute your Jenkins job to build and test your project. Ensure that everything runs smoothly before proceeding to the next step.

Building Your First CI/CD Pipeline with Jenkins

Now that Jenkins is up and running, let's create your first CI/CD pipeline. A CI/CD pipeline automates the process of building, testing, and deploying your code, ensuring a seamless workflow.

Step 1: Define Your Pipeline

You can define your pipeline using a Jenkinsfile (for Pipeline projects) or by configuring the pipeline directly in your job configuration (for Freestyle projects).

Here's an example of a simple Jenkinsfile for a Node.js application:

pipeline {
    agent any

    stages {
        stage('Checkout') {
            steps {
                // Checkout code from version control
                checkout scm
            }
        }

        stage('Build') {
            steps {
                // Build Node.js application
                sh 'npm install'
            }
        }

        stage('Test') {
            steps {
                // Run tests
                sh 'npm test'
            }
        }

        stage('Deploy') {
            steps {
                // Deploy to production
                sh 'npm deploy'
            }
        }
    }
}

Step 2: Version Control Integration

Integrate your version control system (e.g., Git) into your pipeline. Trigger pipeline runs automatically when changes are pushed.

Step 3: Build Stage

Set up your build environment and specify the build commands. Ensure error handling and notifications are in place.

Step 4: Test Stage

Integrate testing frameworks and scripts. Handle test failures gracefully.

Step 5: Deployment Stage

Automate the deployment process to staging or production environments. Implement proper rollback mechanisms.

Step 6: Monitoring and Reporting

Integrate monitoring tools and generate reports to track the health and performance of your application.

Conclusion

Congratulations! You've just embarked on your journey to mastering Jenkins. In this blog, we introduced you to Jenkins, guided you through the setup process, and helped you build your first CI/CD pipeline. Remember that Jenkins is a powerful tool, and the possibilities are endless. Explore its features, customize your pipelines, and streamline your development workflow.

By implementing Jenkins, you'll significantly enhance your software development practices and deliver high-quality code efficiently.

References

Now, you're well-equipped to automate your development pipeline with Jenkins. Stay tuned for more in-depth tutorials on DevOps and software development.

Sarthak Jain