Complete CI/CD Pipeline Setup in GitLab

🚀 Complete CI/CD Pipeline Setup in GitLab (Step-by-Step Guide)

In modern software development, Continuous Integration and Continuous Deployment (CI/CD) are essential for faster and reliable releases. GitLab provides a powerful built-in CI/CD system that enables automated build, test, and deployment workflows.

In this guide, we’ll walk through setting up a complete CI/CD pipeline in GitLab.

📌 What is GitLab CI/CD?

GitLab CI/CD is a built-in DevOps tool that automates:

• Code building
• Testing
• Security scanning
• Deployment

It uses a configuration file called:

.gitlab-ci.yml

This file defines stages, jobs, and scripts.

🏗 Step 1: Create a GitLab Repository

1. Login to GitLab
2. Create a new project
3. Push your code to the repository

⚙ Step 2: Create .gitlab-ci.yml File

Add this file to the root of your project:

stages: - build - test - deploy variables: IMAGE_NAME: my-app build_job: stage: build script: - echo "Building the application" - docker build -t $IMAGE_NAME . test_job: stage: test script: - echo "Running tests" - npm install - npm test deploy_job: stage: deploy script: - echo "Deploying application" only: - main

🏃 Step 3: Setup GitLab Runner

GitLab Runner executes pipeline jobs.

Install Runner:

sudo apt install gitlab-runner

Register Runner:

sudo gitlab-runner register

Provide:

• GitLab URL
• Registration token
• Executor type (docker/shell)

🐳 Step 4: Using Docker in Pipeline

To enable Docker builds:

image: docker:latest services: - docker:dind

This allows containerized builds.

🔐 Step 5: Add CI/CD Variables

Go to:

Settings → CI/CD → Variables

Add:

• DOCKER_USERNAME
• DOCKER_PASSWORD
• API_KEYS
• SERVER_IP

Never hardcode secrets in YAML.

🚀 Step 6: Deployment Strategy

You can deploy to:

• VPS server (via SSH)
• Kubernetes cluster
• AWS EC2
• Azure VM
• DigitalOcean

Example SSH Deployment:

deploy_job: stage: deploy script: - ssh user@server "docker pull $IMAGE_NAME && docker restart app"

📊 Pipeline Flow

1. Developer pushes code
2. GitLab triggers pipeline
3. Build stage runs
4. Test stage validates
5. Deploy stage releases to production

🎯 Best Practices

• Use separate environments (dev, staging, prod)
• Enable branch protection
• Use merge request pipelines
• Enable security scanning
• Cache dependencies for faster builds
• Use Docker for consistency