gitlab-org / gitlab

This documentation provides a detailed guide on setting up and understanding the CI/CD workflow within the gitlab-org/gitlab project.

Overview of CI/CD in gitlab-org/gitlab

The Continuous Integration (CI) and Continuous Deployment (CD) workflows in the gitlab-org/gitlab project are critical for automating testing and deployment processes. The following steps guide expert developers through the effective usage of CI/CD in this project, including configurations and examples.

Step 1: Verify CI/CD Setup

Before setting up the CI/CD pipeline, check if it has been configured in your project. If not, a setup will be necessary.

CI/CD Not Yet Setup

If you find that CI/CD is not yet established for your project, consider taking the following next steps:

  1. Create a .gitlab-ci.yml file at the root of your project repository.
  2. Define jobs and stages that suit your build, test, and deployment needs.
  3. Ensure that runners are correctly configured to execute the jobs.

Step 2: Creating the .gitlab-ci.yml File

For projects with CI/CD already set up, the next step is to edit the .gitlab-ci.yml file. This file defines the CI/CD pipeline.

Example of a Basic CI/CD Configuration

stages:
  - build
  - test
  - deploy

build_job:
  stage: build
  script:
    - echo "Building the application..."
    - docker-compose build

test_job:
  stage: test
  script:
    - echo "Running tests..."
    - docker-compose run app bundle exec rspec

deploy_job:
  stage: deploy
  script:
    - echo "Deploying application..."
    - docker-compose up -d

In this example:

  • Build Stage: Utilizes docker-compose build to build the application.
  • Test Stage: Runs tests with RSpec inside the Docker container.
  • Deploy Stage: Deploys the application using docker-compose up.

Step 3: Setting Up Docker Container

The project utilizes a Docker environment to streamline the CI process. Ensure that your CI environment is set to utilize Docker runners, which can be defined in the configuration file.

Example Docker Configuration

image: gitlab/gitlab-ce:latest

services:
  - docker:dind

before_script:
  - docker info
  - docker login -u gitlab-ci-token -p $CI_JOB_TOKEN $CI_REGISTRY

In this configuration:

  • The image attribute specifies the Docker image for GitLab CE.
  • The services define Docker-in-Docker, allowing the jobs to use Docker commands.
  • The before_script section executes commands that prepare the Docker environment.

Step 4: Running Jobs

Once the .gitlab-ci.yml file is configured, you can commit changes. The CI/CD pipeline will automatically trigger based on your configuration. Monitor the CI/CD tab in the GitLab interface for job statuses, logs, and outputs.

Debugging Issues in CI/CD

When the pipeline fails, it’s essential to check the job logs for error messages. You can include debugging information in the scripts to help pinpoint issues.

Example of Enhanced Script with Debug Logging

test_job:
  stage: test
  script:
    - echo "Running tests..."
    - set -x  # Enable debugging
    - docker-compose run app bundle exec rspec
    - set +x  # Disable debugging

The set -x command allows you to trace the commands being executed, which is beneficial for debugging.

Conclusion

This documentation covers the essential components of setting up and managing the CI/CD workflow within the gitlab-org/gitlab project. For those whose projects are not yet set up for CI/CD, initiating the process with a proper configuration in the .gitlab-ci.yml file offers a structured approach to building, testing, and deploying applications efficiently.

By following these guidelines, expert developers can harness the power of CI/CD to streamline their development processes and enhance quality.

Source: gitlab-org/gitlab CI/CD documentation