GitLab Cheatsheet

GitLab Cheatsheet

GitLab is a web-based DevOps platform that provides a robust set of tools for source code management, CI/CD, project management, and deployment automation. This cheatsheet covers everything from basic usage to advanced GitLab features.

1. Introduction to GitLab

What is GitLab?

GitLab is an open-source DevOps platform offering integrated tools for:

• Source control (Git)
• Continuous Integration/Continuous Deployment (CI/CD)
• Issue tracking and project management
• Container registry and DevSecOps

Key Features

• Git Repository Management: Handles distributed version control and code review.
• CI/CD Pipelines: Automates testing, integration, and deployment.
• DevSecOps: Built-in security scanning for dependencies, container images, and code.
• Container Registry: Docker container management.

2. Basic GitLab Setup

Signing Up and Creating a Project

1. Sign up: Visit GitLab and create an account.
2. Create a Project:
   • Go to Projects → New Project.
   • Choose Blank Project, Import, or Template.
   • Configure visibility (Private, Internal, or Public).

Adding SSH Keys

1. Generate an SSH key:

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   ssh-keygen -t rsa -b 4096 -C "your_email@example.com"

2. Copy the public key:

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   cat ~/.ssh/id_rsa.pub

3. Add the key in GitLab:

   • Go to User Settings → SSH Keys → Paste the public key.

3. GitLab Basics

Cloning a Repository

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git clone git@gitlab.com:username/projectname.git

Committing Changes

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# Stage files
git add .
# Commit files
git commit -m "Initial commit"
# Push changes
git push origin main

Branching

• Create a branch:

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  git checkout -b feature-branch

• Push the branch:

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  git push origin feature-branch

Merge Requests (MRs)

1. Go to your project on GitLab.
2. Navigate to Merge Requests → New Merge Request.
3. Select source and target branches and create an MR.

4. Working with GitLab CI/CD

Basics of .gitlab-ci.yml

The .gitlab-ci.yml file defines the CI/CD pipeline.

Example File:

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stages:
  - build
  - test
  - deploy
 
build_job:
  stage: build
  script:
    - echo "Building the project"
    - ./build-script.sh
 
test_job:
  stage: test
  script:
    - echo "Running tests"
    - ./test-script.sh
 
deploy_job:
  stage: deploy
  script:
    - echo "Deploying to production"
    - ./deploy-script.sh

Pipeline Lifecycle

1. Stages: Define steps (e.g., build, test, deploy).
2. Jobs: Define tasks in each stage.
3. Runners: Execute pipeline jobs (shared or custom).

Running a Pipeline

• Push changes to a branch:

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  git push origin branch-name

• Check pipelines:

  • Navigate to CI/CD → Pipelines in GitLab.

5. Intermediate GitLab Features

GitLab Runners

• Runners execute CI/CD jobs.
• Shared Runners: Provided by GitLab.
• Custom Runners: Self-hosted.

Register a Custom Runner:

1. Install GitLab Runner:

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   sudo apt install gitlab-runner

2. Register the Runner:

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   gitlab-runner register

   • Enter GitLab URL, registration token, executor (e.g., shell, docker), and tags.

Managing Variables

• Set Environment Variables:

  1. Go to Settings → CI/CD → Variables.
  2. Add variables (e.g., AWS_ACCESS_KEY, DOCKER_PASSWORD).

• Use in .gitlab-ci.yml:

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  script:
    - echo $MY_VARIABLE

Artifacts

Artifacts store job outputs.

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test_job:
  stage: test
  script:
    - ./run-tests
  artifacts:
    paths:
      - test-results/

6. Advanced GitLab Features

GitLab Pages

Host static websites directly on GitLab.

Example .gitlab-ci.yml for Pages:

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pages:
  stage: deploy
  script:
    - mkdir .public
    - cp -r * .public
  artifacts:
    paths:
      - public

Container Registry

• GitLab provides a built-in Docker registry for container storage.

• Push an Image:

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  docker build -t registry.gitlab.com/username/projectname:tag .
  docker login registry.gitlab.com
  docker push registry.gitlab.com/username/projectname:tag

GitLab Kubernetes Integration

• Integrate Kubernetes clusters with GitLab for deployments.
• Navigate to Operations → Kubernetes to connect your cluster.

Deploy Using Helm:

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deploy:
  stage: deploy
  script:
    - helm install my-app ./helm-chart

7. Security in GitLab

SAST (Static Application Security Testing)

• Enable SAST to scan for vulnerabilities:

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  include:
    - template: Security/SAST.gitlab-ci.yml

DAST (Dynamic Application Security Testing)

• Perform runtime vulnerability scans:

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  include:
    - template: Security/DAST.gitlab-ci.yml

Secret Detection

• Detect hardcoded secrets:

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  include:
    - template: Security/Secret-Detection.gitlab-ci.yml

8. GitLab Monitoring and Analytics

Pipeline Analytics

• Navigate to Analytics → CI/CD → Pipelines to review pipeline efficiency.

Code Coverage

• Enable coverage reports in .gitlab-ci.yml:

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  test_job:
    stage: test
    script:
      - ./run-tests
    coverage: '/Code Coverage: \d+%/'

Container Scanning

• Scan Docker images for vulnerabilities:

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  include:
    - template: Security/Container-Scanning.gitlab-ci.yml

9. GitLab Backup and Recovery

Backing Up GitLab

• For self-hosted GitLab, run:

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  gitlab-backup create

• Backup includes repositories, CI/CD logs, uploads, and settings.

Restoring GitLab

• Restore a backup:

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  gitlab-restore restore BACKUP_FILE=backup_filename

10. Troubleshooting GitLab

Common Errors

• Pipeline Failures:
  • Check pipeline logs in CI/CD → Jobs.
• Runner Issues:
  • Ensure the runner is active: gitlab-runner status.
• Permission Errors:
  • Verify SSH key and repository access.

Debugging CI/CD Pipelines

• Add verbose logging:

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  script:
    - echo "Debugging info"
    - set -x
    - ./my-script.sh

11. GitLab Best Practices

• Use Branching Strategies:
  • Implement GitLab Flow or GitFlow for streamlined collaboration.
• Secure CI/CD Pipelines:
  • Use environment variables to manage sensitive data.
• Automate Reviews:
  • Use merge request templates and code owners.
• Leverage GitLab Templates:
  • Use pre-built .gitlab-ci.yml templates to save time.
• Monitor Usage:
  • Regularly check project and pipeline analytics.

12. Useful GitLab CLI Commands

Basic Commands

• Login to GitLab CLI:

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  glab auth login

• List Repositories:

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  glab repo list

• Create an Issue:

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  glab issue create --title "Bug report" --description "Details here"

References and Resources

1. GitLab Documentation
2. GitLab CI/CD Examples
3. GitLab CLI

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