CI/CD Case Studies on Linux

1. Introduction

Continuous Integration and Continuous Deployment (CI/CD) are essential practices in modern software development. This lesson focuses on case studies of CI/CD implementations on Linux platforms.

2. Key Concepts

Continuous Integration (CI): Automation of testing and integration of code changes into a shared repository.
Continuous Deployment (CD): Automatic deployment of code changes to production after passing CI.
Pipeline: A series of automated processes that code changes go through to get from development to production.
Version Control: Tools like Git that help manage changes to source code over time.

3. Case Study 1: Jenkins

Overview

Jenkins is an open-source automation server that supports building, deploying, and automating software development tasks.

Setup Steps

Install Jenkins on a Linux server:

sudo apt update
sudo apt install openjdk-11-jdk
sudo apt install jenkins

Start Jenkins:

sudo systemctl start jenkins

Access Jenkins at http://localhost:8080.
Install necessary plugins (e.g., Git, Pipeline).
Create a new job and configure the build pipeline.

Example Pipeline Script

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

4. Case Study 2: GitLab CI

Overview

GitLab CI is built into GitLab and allows CI/CD to be integrated directly into the version control system.

Setup Steps

Sign up for GitLab and create a new repository.
Create a file named .gitlab-ci.yml in the root of your repository:

stages:
  - build
  - test
  - deploy

build_job:
  stage: build
  script:
    - echo "Building..."

test_job:
  stage: test
  script:
    - echo "Testing..."

deploy_job:
  stage: deploy
  script:
    - echo "Deploying..."

Push the changes to your GitLab repository.

5. Best Practices

Automate as much as possible to reduce human error.
Run tests in a clean environment to ensure consistency.
Use containerization tools like Docker for environment consistency.
Implement proper logging and monitoring for deployments.

6. FAQ

What is the difference between CI and CD?

CI focuses on automating the integration of code changes, while CD automates the deployment of those changes to production.

Can I use CI/CD without Docker?

Yes, you can implement CI/CD without Docker, but containerization can simplify the process and ensure environment consistency.

What tools can I use for CI/CD?

Common tools include Jenkins, GitLab CI, Travis CI, CircleCI, and Azure DevOps.