Wiki functionality in GitLab uses Git repositories as the storage backend and is accessed from the Rails app through Gitaly RPC calls.

You can access wikis through:

• The Web UI
• The REST API
• Git itself

Involved Gems

Some notable gems that are used for wikis are:

Wiki rendering

When rendering wiki pages, we use a custom Banzai pipeline. This pipeline adds wiki-specific markup, such as the [[link]] syntax.

Model classes

The Wiki class is the main abstraction around a wiki repository. You must initialize it with a container, which can be either a Project or Group:

classDiagram
  Wiki --> ProjectWiki
  Wiki --> GroupWiki

  class Wiki {
    #container
    #repository
  }

  class ProjectWiki {
    #project → #container
  }

  class GroupWiki {
    #group → #container
  }

Some models wrap similar classes from Gitaly:

Only some data is persisted in the database:

Attachments

The web UI uploads attachments through the REST API, which stores the files as commits in the wiki repository.