How to Set Up a CI/CD Pipeline with GitLab: A Beginner's Guide

Introduction to CI/CD and GitLab

In modern software development, Continuous Integration (CI) and Continuous Deployment (CD) are essential practices. CI involves automatically integrating code changes into a shared repository multiple times a day, while CD focuses on deploying the integrated code to production automatically. These practices help ensure high software quality and faster release cycles.

GitLab is a comprehensive DevOps platform that integrates source control, CI/CD, and other DevOps tools. This guide will walk you through setting up a simple CI/CD pipeline on GitLab, perfect for beginners and intermediate users.

Prerequisites and Setup

Tools Needed:

GitLab Account: Sign up at GitLab.
Git Installed: Download and install Git from Git's official site.

Basic Knowledge Required:

Basic understanding of Git commands.
Familiarity with GitLab's interface.

Creating a GitLab Repository

1. Log In to GitLab:

Go to GitLab and log in with your credentials.

2. Create a New Project:

Click on the "New Project" button.
Select "Create blank project".
Fill in the project name (e.g., MyFirstPipeline), description (optional), and set the visibility level.
Click "Create project".

3. Clone the Repository:

Copy the HTTPS clone URL from the GitLab repository page.

Open your terminal and run:

   git clone <your-repository-URL>
   cd <your-repository-name>

4. Add Initial Files:

Create a simple application or add existing files to the repository.

For example, create an index.html file for a static website:

   echo "<!DOCTYPE html>
   <html>
   <head>
       <title>Welcome to My First Project</title>
   </head>
   <body>
       <h1>Hello, World!</h1>
       <p>This is my first static website hosted using GitLab CI/CD.</p>
   </body>
   </html>" > index.html

5. Commit and Push the Changes:

Add the file to your repository:

   git add index.html
   git commit -m "Add index.html for static website"
   git push origin main

Writing a `.gitlab-ci.yml` File

The .gitlab-ci.yml file defines the stages, jobs, and scripts for your CI/CD pipeline. Here's a simple configuration:

** Create the .gitlab-ci.yml File**:

In the root directory of your project, create a file named .gitlab-ci.yml.

Open the file and add the following content:

   stages:
     - build
     - deploy

   build_job:
     stage: build
     script:
       - echo "Building the project..."
       - echo "Build complete."

   deploy_job:
     stage: deploy
     script:
       - echo "Deploying the project..."
       - echo "Deploy complete."

** Commit and Push the Changes**:

Add the file to your repository:

   git add .gitlab-ci.yml
   git commit -m "Add CI/CD pipeline configuration"
   git push origin main

Running and Monitoring the Pipeline

Trigger the Pipeline: The pipeline will automatically trigger when you push the .gitlab-ci.yml file.
Monitor the Pipeline:
- Go to your GitLab project page.
- Navigate to CI/CD > Pipelines.
- You should see a new pipeline triggered by your recent push.
- Click on the pipeline to monitor its progress and view job logs.
Check Job Logs:
- View the output logs for each job (build and deploy) to ensure they are executing correctly.

Conclusion

Congratulations! You've successfully set up a basic CI/CD pipeline using GitLab. Here’s a quick summary of what we did:

Created a GitLab repository.
Added a simple index.html file to the repository.
Configured a .gitlab-ci.yml file to define our CI/CD pipeline stages and jobs.
Triggered and monitored the pipeline.