How to Create a Basic GitLab CI Pipeline: Automating Script Execution on Push

GitLab CI/CD (Continuous Integration/Continuous Delivery) allows you to automate tasks such as running scripts, building projects, or running tests automatically whenever changes are pushed to your GitLab repository. In this blog, we’ll walk through creating a .gitlab-ci.yml file to define a simple pipeline that runs a script every time you push changes.

Table of Contents

1. What is GitLab CI/CD?
2. Step 1: Set Up a GitLab Repository
3. Step 2: Create a Basic Script
4. Step 3: Define a .gitlab-ci.yml File
5. Step 4: Push Changes and Trigger the Pipeline
6. Conclusion

What is GitLab CI/CD?

GitLab CI/CD is a built-in feature that automates the execution of scripts and workflows whenever you make changes to your GitLab repository. The pipeline can run tests, check code quality, or even deploy your application. The .gitlab-ci.yml file is where you define these jobs and pipelines.

Step 1: Set Up a GitLab Repository

If you don’t already have a GitLab repository, follow these steps to create one:

1. Log in to GitLab.
2. Click New Project on the dashboard.
3. Enter the project name and visibility level, then click Create Project.
4. Clone the repository locally using the command:

git clone https://gitlab.com/username/your-repository.git

5. Navigate into the repository directory:

cd your-repository

Now that you have a repository set up, let’s create a simple script that we will automate.

Step 2: Create a Basic Script

For this guide, we’ll create a basic script that prints “Hello, GitLab CI!” to the terminal. In your repository, create a new file called script.sh:

#!/bin/bash
echo "Hello, GitLab CI!"

Make sure the script has execute permissions by running:

chmod +x script.sh

Now we can define the pipeline that will execute this script whenever code is pushed to the repository.

Step 3: Define a .gitlab-ci.yml File

The heart of the GitLab CI/CD process is the .gitlab-ci.yml file, which contains all the instructions for running jobs and pipelines.

1. In the root of your repository, create a file named .gitlab-ci.yml:

touch .gitlab-ci.yml

2. Open the file in a text editor and add the following content:

stages:
  - test

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

Explanation:

• stages: Specifies the stages of the pipeline. In this case, we have a single stage called test.
• run-script-job: Defines the job that will run in the pipeline.
• stage: test: Specifies that this job belongs to the test stage.
• script: The commands that the job will execute. Here, we are running the script.sh file we created earlier.

Step 4: Push Changes and Trigger the Pipeline

Once you’ve defined the .gitlab-ci.yml file and the script, commit the changes and push them to the GitLab repository:

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

After pushing, GitLab will automatically trigger the pipeline based on the .gitlab-ci.yml configuration.

View the Pipeline:

1. Go to your GitLab repository.
2. On the left sidebar, click CI/CD > Pipelines.
3. You should see the pipeline running. Once it completes, you’ll see a green checkmark if the job was successful.

Click on the pipeline to view the logs. The output should display “Hello, GitLab CI!” as expected from our script.

Conclusion

In this blog, we’ve demonstrated how to create a simple GitLab CI pipeline that automatically runs a script whenever changes are pushed to the repository. By defining a .gitlab-ci.yml file, you can automate various tasks like testing, building, or deploying your applications with ease.

GitLab CI/CD is a powerful tool that enables seamless automation, enhancing the efficiency of your development workflow. Stay tuned for more advanced GitLab CI/CD tutorials, where we’ll explore multi-stage pipelines, job dependencies, and deploying applications.