GitLab Master Guide¶

GitLab is a web-based Git repository manager with wiki and issue tracking features. It provides a comprehensive platform for version control, continuous integration, and continuous deployment (CI/CD). This guide will walk you through the installation process and various scenarios for using GitLab, tailored for beginners, intermediate users, and advanced users.

Installation Guide¶

Using Docker (Recommended)¶

Install Docker: Follow the installation instructions for your operating system from Docker's official website.

Run GitLab via Docker:

docker run --detach \
  --hostname gitlab.example.com \
  --publish 443:443 --publish 80:80 --publish 22:22 \
  --name gitlab \
  --restart always \
  --volume /srv/gitlab/config:/etc/gitlab \
  --volume /srv/gitlab/logs:/var/log/gitlab \
  --volume /srv/gitlab/data:/var/opt/gitlab \
  gitlab/gitlab-ce:latest

Access GitLab: Open your web browser and navigate to http://gitlab.example.com. Follow the initial setup instructions.

On Ubuntu¶

Add GitLab Repository:

sudo apt-get update
sudo apt-get install -y curl
curl https://packages.gitlab.com/install/repositories/gitlab/gitlab-ce/script.deb.sh | sudo bash

Install GitLab:
```
sudo apt-get install -y gitlab-ce
```
Configure GitLab: Edit the /etc/gitlab/gitlab.rb file to configure GitLab settings.
Reconfigure GitLab:
```
sudo gitlab-ctl reconfigure
```
Access GitLab: Open your web browser and navigate to http://your-server-ip.

BEGINNER LEVEL: First Steps with GitLab¶

Scenario 1: Setting Up GitLab for the First Time¶

Unlocking GitLab and installing essential plugins.

sequenceDiagram
    participant Developer
    participant GitLab Server
    Developer->>GitLab Server: Access GitLab URL
    GitLab Server->>Developer: Show initial setup page
    Developer->>GitLab Server: Set root password
    GitLab Server->>Developer: Redirect to login page
    Developer->>GitLab Server: Login with root credentials
    GitLab Server->>Developer: Show dashboard

# Access GitLab URL in your browser
# Set root password when prompted
# Login with root user and the set password

Scenario 2: Creating Your First Project¶

Creating a new project and adding a file.

sequenceDiagram
    participant Developer
    participant GitLab Server
    Developer->>GitLab Server: Click "New Project"
    GitLab Server->>Developer: Show project creation form
    Developer->>GitLab Server: Fill project details
    GitLab Server->>Developer: Create project
    Developer->>GitLab Server: Add README.md
    GitLab Server->>Developer: Commit file

# Create a new project via GitLab UI
# Add a README.md file via GitLab UI
# Commit the file

Scenario 3: Cloning a Project¶

Cloning a project to your local machine.

sequenceDiagram
    participant Developer
    participant GitLab Server
    Developer->>GitLab Server: Get project URL
    Developer->>GitLab Server: Clone project
    GitLab Server->>Developer: Download project files

# Get the project URL from GitLab
git clone http://gitlab.example.com/your-project.git
cd your-project

INTERMEDIATE LEVEL: Working with GitLab CI/CD¶

Scenario 4: Setting Up CI/CD Pipeline¶

Creating a .gitlab-ci.yml file for CI/CD.

sequenceDiagram
    participant Developer
    participant GitLab Server
    Developer->>GitLab Server: Create .gitlab-ci.yml
    GitLab Server->>Developer: Detect CI/CD configuration
    Developer->>GitLab Server: Push changes
    GitLab Server->>Developer: Trigger pipeline
    GitLab Server->>Developer: Run jobs

# .gitlab-ci.yml
stages:
  - build
  - test
  - deploy

build_job:
  stage: build
  script:
    - echo "Building the project"

test_job:
  stage: test
  script:
    - echo "Running tests"

deploy_job:
  stage: deploy
  script:
    - echo "Deploying the project"

Scenario 5: Using GitLab Runner¶

Setting up GitLab Runner for CI/CD.

sequenceDiagram
    participant Developer
    participant GitLab Server
    Developer->>GitLab Server: Install GitLab Runner
    Developer->>GitLab Server: Register Runner
    GitLab Server->>Developer: Runner ready

# Install GitLab Runner
sudo apt-get install -y gitlab-runner

# Register Runner
sudo gitlab-runner register

ADVANCED LEVEL: Advanced GitLab Features¶

Scenario 6: Using GitLab Merge Requests¶

Creating and managing merge requests.

sequenceDiagram
    participant Developer
    participant GitLab Server
    Developer->>GitLab Server: Create new branch
    Developer->>GitLab Server: Push changes
    Developer->>GitLab Server: Create merge request
    GitLab Server->>Developer: Review and merge

# Create a new branch
git checkout -b feature/new-feature

# Push changes
git push origin feature/new-feature

# Create a merge request via GitLab UI

Scenario 7: GitLab Security Scanning¶

Setting up security scanning for your project.

sequenceDiagram
    participant Developer
    participant GitLab Server
    Developer->>GitLab Server: Add security scan job
    Developer->>GitLab Server: Push changes
    GitLab Server->>Developer: Run security scan
    GitLab Server->>Developer: Report vulnerabilities

# .gitlab-ci.yml
stages:
  - build
  - test
  - security

build_job:
  stage: build
  script:
    - echo "Building the project"

test_job:
  stage: test
  script:
    - echo "Running tests"

security_scan:
  stage: security
  script:
    - echo "Running security scan"
    - gitlab-sast

Quick Reference: Essential Commands¶

Command	Description	Level
`git clone`	Clone a repository	Beginner
`git push`	Push changes to remote	Beginner
`git pull`	Pull changes from remote	Beginner
`git checkout`	Switch branches	Intermediate
`git merge`	Merge branches	Intermediate
`git rebase`	Rebase branch	Advanced
`git stash`	Stash changes	Intermediate
`git bisect`	Find bad commit	Advanced

Pro Tips for All Levels¶

Use descriptive commit messages: "Fix login bug" > "Update stuff".
Commit early, commit often: Small commits are easier to manage.
Never git reset --hard on shared branches: It rewrites history.
Use branches for every feature: Keep the main branch clean.
Review before committing: git diff --staged shows what you're about to commit.
Configure helpful aliases: git config --global alias.co checkout.