GitLab development guides

Get started!

• Set up GitLab's development environment with GitLab Development Kit (GDK)
• GitLab contributing guide
• Architecture of GitLab
• Rake tasks for development

Processes

• GitLab core team & GitLab Inc. contribution process
• Generate a changelog entry with bin/changelog
• Code review guidelines for reviewing code and having code reviewed.
• Automatic CE->EE merge
• Guidelines for implementing Enterprise Edition features
• Security process for developers

UX and frontend guides

• GitLab Design System for building GitLab with existing CSS styles and elements
• Frontend guidelines
• Emoji guide

Backend guides

• GitLab utilities
• Logging
• API styleguide Use this styleguide if you are contributing to the API.
• GraphQL API styleguide Use this styleguide if you are contribution to the GraphQL API
• Sidekiq guidelines for working with Sidekiq workers
• Working with Gitaly
• Manage feature flags
• View sent emails or preview mailers
• Shell commands in the GitLab codebase
• Gemfile guidelines
• Pry debugging
• Sidekiq debugging
• Gotchas to avoid
• Avoid modules with instance variables if possible
• How to dump production data to staging
• Working with the GitHub importer
• Working with Merge Request diffs
• Permissions
• Prometheus metrics
• Guidelines for reusing abstractions
• DeclarativePolicy framework
• Switching to Rails 5

Performance guides

• Instrumentation for Ruby code running in production environments
• Performance guidelines for writing code, benchmarks, and certain patterns to avoid
• Merge request performance guidelines for ensuring merge requests do not negatively impact GitLab performance
• Profiling a URL, measuring performance using Sherlock, or tracking down N+1 queries using Bullet

Database guides

Tooling

• Understanding EXPLAIN plans
• explain.depesz.com for visualising the output of EXPLAIN

Migrations

• What requires downtime?
• SQL guidelines for working with SQL queries
• Migrations style guide for creating safe SQL migrations
• Post deployment migrations
• Background migrations
• Swapping tables

Best practices

• Merge Request checklist
• Adding database indexes
• Foreign keys & associations
• Single table inheritance
• Polymorphic associations
• Serializing data
• Hash indexes
• Storing SHA1 hashes as binary
• Iterating tables in batches
• Ordering table columns
• Verifying database capabilities
• Database Debugging and Troubleshooting
• Query Count Limits
• Database helper modules

Testing guides

• Testing standards and style guidelines
• Frontend testing standards and style guidelines

Documentation guides

• Writing documentation
• Documentation styleguide
• Markdown

Internationalization (i18n) guides

• Introduction
• Externalization
• Translation

Build guides

• Building a package for testing purposes

Compliance

• Licensing for ensuring license compliance