Redirects in GitLab documentation

When you move, rename, or delete a page, you must add a redirect. Redirects reduce how often users get 404s when visiting the documentation site from out-of-date links, like:

Bookmarks
Links from external sites
Links from old blog posts
Links in the documentation site global navigation

Add a redirect to ensure:

Users see the new page and can update or delete their bookmark.
External sites can update their links, especially sites that have automation that check for redirecting links.
The documentation site global navigation does not link to a missing page.

The links in the global navigation are already tested in the gitlab-docs project. If the redirect is missing, the gitlab-docs project's main branch might break.

Be sure to assign a technical writer to any merge request that moves, renames, or deletes a page. Technical Writers can help with any questions and can review your change.

There are two types of redirects:

Redirect added into the documentation files themselves, for users who view the docs in /help on self-managed instances. For example, /help on GitLab.com.
GitLab Pages redirects, for users who view the docs on docs.gitlab.com.

The Technical Writing team manages the process to regularly update and clean up the redirects. If you're a contributor, you may add a new redirect, but you don't need to delete the old ones. This process is automatic and handled by the Technical Writing team.

NOTE: If the old page you're renaming doesn't exist in a stable branch, skip the following steps and ask a Technical Writer to add the redirect in redirects.yaml. For example, if you add a new page on the 3rd of the month and then rename it before it gets added in the stable branch on the 18th, the old page will never be part of the internal /help. In that case, you can jump straight to the Pages redirect.

To add a redirect:

In the repository (gitlab, gitlab-runner, omnibus-gitlab, or charts), create a new documentation file. Don't delete the old one. The easiest way is to copy it. For example:
```
cp doc/user/search/old_file.md doc/api/new_file.md
```
Add the redirect code to the old documentation file by running the following Rake task. The first argument is the path of the old file, and the second argument is the path of the new file:
- To redirect to a page in the same project, use relative paths and the .md extension. Both old and new paths start from the same location. In the following example, both paths are relative to doc/:
```
bundle exec rake "gitlab:docs:redirect[doc/user/search/old_file.md, doc/api/new_file.md]"
```
- To redirect to a page in a different project or site, use the full URL (with https://) :
```
bundle exec rake "gitlab:docs:redirect[doc/user/search/old_file.md, https://example.com]"
```
Alternatively, you can omit the arguments and be asked to enter their values:
```
bundle exec rake gitlab:docs:redirect
```
If you don't want to use the Rake task, you can use the following template.

Replace the value of redirect_to with the new file path and YYYY-MM-DD with the date the file should be removed.

Redirect files that link to docs in internal documentation projects are removed after three months. Redirect files that link to external sites are removed after one year:
```
---
redirect_to: '../newpath/to/file/index.md'
remove_date: 'YYYY-MM-DD'
---

This document was moved to [another location](../path/to/file/index.md).



```
If the documentation page being moved has any Disqus comments, follow the steps described in Redirections for pages with Disqus comments.
Open a merge request with your changes. If a documentation page you're removing includes images that aren't used with any other documentation pages, be sure to use your merge request to delete those images from the repository.
Assign the merge request to a technical writer for review and merge.
Search for links to the old documentation file. You must find and update all links that point to the old documentation file:
- In https://gitlab.com/gitlab-com/www-gitlab-com, search for full URLs: grep -r "docs.gitlab.com/ee/path/to/file.html" .
- In https://gitlab.com/gitlab-org/gitlab-docs/-/tree/master/content/_data, search the navigation bar configuration files for the path with .html: grep -r "path/to/file.html" .
- In any of the four internal projects, search for links in the docs and codebase. Search for all variations, including full URL and just the path. For example, go to the root directory of the gitlab project and run:
```
grep -r "docs.gitlab.com/ee/path/to/file.html" .
grep -r "path/to/file.html" .
grep -r "path/to/file.md" .
grep -r "path/to/file" .
```
  You may need to try variations of relative links, such as ../path/to/file or ../file to find every case.

Redirections for pages with Disqus comments

If the documentation page being relocated already has Disqus comments, we need to preserve the Disqus thread.

Disqus uses an identifier per page, and for https://docs.gitlab.com, the page identifier is configured to be the page URL. Therefore, when we change the document location, we need to preserve the old URL as the same Disqus identifier.

To do that, add to the front matter the variable disqus_identifier, using the old URL as value. For example, let's say we moved the document available under https://docs.gitlab.com/my-old-location/README.html to a new location, https://docs.gitlab.com/my-new-location/index.html.

Into the new document front matter, we add the following information. You must include the filename in the disqus_identifier URL, even if it's index.html or README.html.

---
disqus_identifier: 'https://docs.gitlab.com/my-old-location/README.html'
---