GitLab CI/CD Pipeline Setup Guide

Introduction

This guide demonstrates how to set up a GitLab CI/CD pipeline that automatically executes a script every time you push changes to a GitLab repository. By the end of this setup, you will have a basic automated pipeline that runs a simple script using GitLab’s .gitlab-ci.yml file.

Prerequisites

A GitLab account.
Git installed locally.
Basic knowledge of shell scripting.

Step 1: Set Up a GitLab Repository

Create a New Project in GitLab:
- Log into your GitLab account and click New Project on the dashboard.
- Enter the project name and select your preferred visibility level (e.g., Public, Private).
- Click Create Project to initialize the repository.
Clone the Repository Locally:
- Once the repository is created, clone it to your local machine:
```
  git clone https://gitlab.com/username/your-repository.git
```
- Replace username and your-repository with your GitLab username and repository name, respectively.
- Move into the repository’s directory:
```
  cd your-repository
```

Step 2: Create a Basic Script

Add a Script File (script.sh):
- In the repository, create a file called script.sh:
```
  touch script.sh
```
- Open the file in your preferred editor and add the following code:
```
  #!/bin/bash
  echo "Hello, GitLab CI!"
```
Grant Execute Permissions:
- Make the script executable by running:
```
  chmod +x script.sh
```

Step 3: Define the `.gitlab-ci.yml` File

The .gitlab-ci.yml file is the configuration file for defining your CI/CD pipeline stages and jobs.

Create the .gitlab-ci.yml File:

At the root of your repository, create a new file:
```
  touch .gitlab-ci.yml
```

Open the file and add the following configuration:

  stages:
    - test

  run-script-job:
    stage: test
    script:
      - ./script.sh

Explanation of Configuration:

stages: Defines the stages in the pipeline, with a single stage called test.
run-script-job: The name of the job that will run during the test stage.
script: Commands to execute within this job, where we’re running the script script.sh.

Step 4: Push Changes and Trigger the Pipeline

Commit and Push Changes:

Add, commit, and push your files to the GitLab repository:

  git add .
  git commit -m "Add basic GitLab CI pipeline"
  git push origin main

View the Pipeline Execution:
- In GitLab, go to CI/CD > Pipelines in your repository.
- You should see a pipeline running based on the .gitlab-ci.yml configuration. Once the pipeline completes, you’ll see a green checkmark if the job was successful.
- Click the pipeline to view logs and check if the output shows Hello, GitLab CI! from the script.

Summary

In this guide, you set up a GitLab CI/CD pipeline that automates the execution of a script upon every code push. This setup serves as a foundation for adding more stages, jobs, and tasks to your pipeline, such as testing, building, or deploying applications.

GitLab CI/CD is a powerful tool for automating workflows and improving development efficiency.