GitLab Architecture

Overview

The GitLab application consists of several components, including a web application, a database, and a background processing system. These components are designed to work together to provide a comprehensive Git repository management, issue tracking, and continuous integration and continuous delivery (CI/CD) platform.

Components:

  • Web Application: The GitLab web application is a Ruby on Rails application responsible for providing the user interface and handling user interactions. It communicates with the database and the background processing system to provide functionality.
  • Database: The GitLab database stores all of the application data, including projects, users, issues, and code. GitLab supports several database systems, including PostgreSQL and MySQL.
  • Background Processing System: The background processing system, powered by Sidekiq, handles asynchronous tasks such as repository updates, CI/CD pipelines, and email notifications.

Architecture Diagram:

Architecture Diagram

Interaction Flow:

  1. A user interacts with the GitLab web application through a web browser.
  2. The web application handles user requests and interacts with the database to retrieve or update data.
  3. If necessary, the web application enqueues tasks in the background processing system, such as code updates or CI/CD pipeline execution.
  4. The background processing system processes the tasks asynchronously, updating the database and potentially interacting with other services like GitLab Runner.
  5. The web application updates its state and provides feedback to the user.

Deployment:

GitLab can be deployed in several ways, including:

  • On-premise: GitLab can be installed and configured on your own servers.
  • Cloud: GitLab can be deployed on various cloud providers, including AWS, Google Cloud, and Azure.

Scalability:

GitLab is designed to scale horizontally by adding more servers or instances. The background processing system can be scaled independently to handle increased workload.

Security:

GitLab includes features to enhance security, such as:

  • Two-factor authentication: Adds an extra layer of security to user accounts.
  • Role-based access control (RBAC): Allows administrators to control user permissions and access to resources.
  • Security scanning: Provides vulnerability scanning for projects and code.

Reference Materials: