The goal of this tutorial is to help beginners understand the basic principles of Continuous Integration (CI) and Continuous Deployment (CD) pipelines, collectively known as CI/CD pipelines.
By the end of this tutorial, you will be able to:
Prior knowledge of version control systems like Git and basic knowledge of software development is required.
CI is a development practice where developers integrate their code into a shared repository frequently, usually multiple times per day. Each integration can then be verified by an automated build and tests.
# Code is pushed to a shared repository
git push origin master
# An automated build runs to verify the integration
# Output is either success (build passes) or failure (build fails)
CD is a development practice where software is automatically deployed to production after passing through stages of testing, staging, and production in the CI/CD pipeline.
# After successful tests, code is automatically deployed
# Code is now live in production environment
Jenkins is a popular open-source tool used for implementing CI/CD pipelines.
# Install Jenkins
apt-get install Jenkins
# Start Jenkins service
service jenkins start
After Jenkins is installed and started, you can access Jenkins on your local machine at http://localhost:8080
.
// Jenkinsfile (Declarative Pipeline)
pipeline {
agent any
stages {
stage('Build') {
steps {
// Build your project here
echo 'Building..'
}
}
stage('Test') {
steps {
// Test your project here
echo 'Testing..'
}
}
stage('Deploy') {
steps {
// Deploy your project here
echo 'Deploying....'
}
}
}
}
This Jenkinsfile defines a simple pipeline with three stages: Build, Test, and Deploy.
In this tutorial, we have learned:
For further learning, you can explore more advanced features of Jenkins and other CI/CD tools like Travis CI, Circle CI, etc.
Set up a basic CI/CD pipeline for a simple Hello World application in any language of your choice. The pipeline should have at least two stages: Build and Test.
Expand the pipeline you created in Exercise 1 by adding a Deploy stage. This stage should simulate a deployment process by simply printing a message, e.g. "Deploying...".
Explore the Jenkins dashboard. Create a new pipeline, and familiarize yourself with the different options and configurations.
Solutions will vary based on the language and application. The key is to understand the principles of CI/CD and how to implement them using tools like Jenkins. For further practice, try expanding the pipeline with more stages or integrating with other tools like Docker or Kubernetes.