Automating Deployments with Jenkins

July 21, 2025

In DevOps, Continuous Integration and Continuous Deployment (CI/CD) are vital for delivering software today. Jenkins is a popular open-source automation server that helps automate the building, testing, and deployment of your code.

This guide explains how Jenkins works and shows you how to set up CI/CD pipelines with Jenkins to improve your delivery workflow.

Why Jenkins?

Plugin-rich: Over 1,800 plugins are available for Git, Docker, Kubernetes, AWS, and more.
Extensible: It easily supports custom scripts and configurations.
Automates everything: It builds, tests, and deploys; you can manage everything hands-off after the setup.
Flexible pipelines: It supports both freestyle and scripted pipelines.

Installing Jenkins

On Ubuntu:

sudo apt update
sudo apt install openjdk-11-jdk
wget -q -O – https://pkg.jenkins.io/debian/jenkins.io.key | sudo apt-key add –
sudo sh -c ‘echo deb https://pkg.jenkins.io/debian-stable binary/ > /etc/apt/sources.list.d/jenkins.list’
sudo apt update
sudo apt install jenkins
sudo systemctl start jenkins

Visit http://localhost:8080 and follow the setup wizard.

Key Jenkins Concepts

Job: A unit of work (build + test + deploy).
Build Trigger: What starts the job (for example, a Git push, CRON, or webhook).
Pipeline: Defines the steps of the software delivery process.
Agent: The machine where builds run.
Stage: A block inside the pipeline for each step (for example, Build or Test).

Example Jenkins Pipeline

Create a Jenkinsfile in your repo:

pipeline {
agent any
stages {
    stage(‘Build’) {
      steps {
        sh ‘npm install’
      }
    }
    stage(‘Test’) {
      steps {
        sh ‘npm test’
      }
    }
    stage(‘Deploy’) {
      steps {
        sh ‘./deploy.sh’
      }
    }
}
}

Push to GitHub, and Jenkins will run the pipeline on changes.

Popular Jenkins Plugins

Git Plugin: Clone from GitHub or Bitbucket.
Blue Ocean: Offers a visually appealing pipeline UI.
Slack Notifications: Sends pipeline updates to Slack.
Docker Plugin: Builds and deploys Docker containers.
Kubernetes Plugin: Runs agents inside a Kubernetes cluster.

Security Best Practices

Use credentials bindings to store API keys securely.
Avoid hardcoding secrets in your Jenkinsfile.
Enable role-based access control (RBAC) for team permissions.
Keep Jenkins and its plugins updated.

Integration Examples

Automatically deploy React apps to Netlify.
Build and push Docker images to Docker Hub or AWS ECR.
Run tests in CI using Jest, Mocha, PyTest, or JUnit.
Deploy to Kubernetes or DigitalOcean using kubectl.

With Jenkins, you can move from manual deployments to a fully automated CI/CD pipeline quickly. Whether you are a solo developer or managing large-scale systems, Jenkins speeds up delivery while minimizing errors. It is the backbone of modern DevOps.

Posted in Frameworks, UncategorizedTagged #deploymentwithjenkins, #jenkins

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