O que é Jenkins | Guia prático para começar com Jenkins

Introduction

This tutorial provides a comprehensive guide to getting started with Jenkins, a leading tool for Continuous Integration and Continuous Deployment (CI/CD). Jenkins automates the development process, making it easier to manage software builds and deployments. Whether you're new to DevOps or looking to enhance your skills, this guide will walk you through the essentials of Jenkins, from installation to creating effective pipelines.

Step 1: Understanding Jenkins

• Jenkins is an open-source automation server that supports building, deploying, and automating projects.
• It enables developers to integrate changes into the project more frequently, leading to faster development cycles.
• Key features include:
  • Extensible with a wide range of plugins.
  • Supports distributed builds across multiple machines.
  • Provides real-time feedback on the integration process.

Step 2: Installing Jenkins

Installation on Different Platforms

• Windows

  1. Download the Jenkins installer from the Jenkins website.
  2. Run the installer and follow the setup wizard.
  3. Once installed, Jenkins will start automatically. Access it at http://localhost:8080.

• macOS

  1. Use Homebrew to install Jenkins by running:

     brew install jenkins-lts
     

  2. Start Jenkins with:

     brew services start jenkins-lts
     

  3. Access Jenkins at http://localhost:8080.

• Linux

  1. Import the repository key:

     wget -q -O - https://pkg.jenkins.io/debian/jenkins.io.key | sudo apt-key add -
     

  2. Add the Jenkins repository:

     sudo sh -c 'echo deb http://pkg.jenkins.io/debian-stable binary/ > /etc/apt/sources.list.d/jenkins.list'
     

  3. Update the package index and install Jenkins:

     sudo apt-get update
     sudo apt-get install jenkins
     

  4. Start Jenkins with:

     sudo systemctl start jenkins
     

  5. Access at http://localhost:8080.

Step 3: Setting Up Jenkins

• Upon first access, you will be prompted to unlock Jenkins using an initial admin password found in:
  • Windows: C:\Program Files\Jenkins\secrets\initialAdminPassword
  • macOS/Linux: /var/lib/jenkins/secrets/initialAdminPassword
• Follow the setup wizard to install suggested plugins and create your first admin user.

Step 4: Creating CI/CD Pipelines

Basic Pipeline Creation

1. From the Jenkins dashboard, click on "New Item."
2. Enter a name for your pipeline and select "Pipeline" as the item type.
3. Scroll to the "Pipeline" section and define your pipeline script. A simple example:

   pipeline {
       agent any
       stages {
           stage('Build') {
               steps {
                   echo 'Building...'
               }
           }
           stage('Test') {
               steps {
                   echo 'Testing...'
               }
           }
           stage('Deploy') {
               steps {
                   echo 'Deploying...'
               }
           }
       }
   }
   

4. Save and build your pipeline to see it in action.

Step 5: Integrating Jenkins with Docker and Kubernetes

• Docker Integration

  1. Install the Docker plugin in Jenkins.
  2. Create a Dockerfile in your project repository.
  3. Use the docker commands in your pipeline to build and push images.

• Kubernetes Integration

  1. Install the Kubernetes plugin in Jenkins.
  2. Configure the Kubernetes cloud in Jenkins under Manage Jenkins > Configure System.
  3. Use the Kubernetes plugin in your pipeline to deploy applications to your Kubernetes cluster.

Conclusion

Jenkins is a powerful tool for automating your CI/CD processes. You have learned how to install Jenkins on various platforms, set it up, create basic pipelines, and integrate it with Docker and Kubernetes. As a next step, explore more complex pipelines and Jenkins plugins to enhance your automation capabilities even further. Consider joining Jenkins communities or forums to share experiences and learn from others.