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

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

Adding SSH Keys

Generate an SSH key:

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

Copy the public key:
```
cat ~/.ssh/id_rsa.pub
```
Add the key in GitLab:
- Go to User Settings → SSH Keys → Paste the public key.

3. GitLab Basics

Cloning a Repository

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

Committing Changes

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

Branching

Create a branch:
```
git checkout -b feature-branch
```
Push the branch:
```
git push origin feature-branch
```

Merge Requests (MRs)

Go to your project on GitLab.
Navigate to Merge Requests → New Merge Request.
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:

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

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

Running a Pipeline

Push changes to a branch:
```
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:

Install GitLab Runner:
```
sudo apt install gitlab-runner
```
Register the Runner:
```
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:
```
script:
  - echo $MY_VARIABLE
```

Artifacts

Artifacts store job outputs.

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:

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:

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:

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:

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

DAST (Dynamic Application Security Testing)

Perform runtime vulnerability scans:

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

Secret Detection

Detect hardcoded secrets:

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:

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

Container Scanning

Scan Docker images for vulnerabilities:

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

9. GitLab Backup and Recovery

Backing Up GitLab

For self-hosted GitLab, run:
```
gitlab-backup create
```
Backup includes repositories, CI/CD logs, uploads, and settings.

Restoring GitLab

Restore a backup:

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:

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:
```
glab auth login
```
List Repositories:
```
glab repo list
```

Create an Issue:

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

FilesExpand file tree

GitLab.md

Latest commit

History