Add relative links check

Also fix instances new rule breaks.

doc/.linting/vale/styles/gitlab/RelativeLinks.yml

+---
+# Checks for the presence of absolute hyperlinks that should be relative.
+#
+# Requires --ignore-syntax CLI flag to find matches.
+#
+# For a list of all options, see https://errata-ai.github.io/vale/styles/
+extends: existence
+message: URL '%s' must be relative.
+link: https://docs.gitlab.com/ee/development/documentation/styleguide.html#links-to-internal-documentation
+level: error
+raw:
+  - '\[.+\]\(https?:\/\/docs\.gitlab\.com\/ee.*\)'

doc/administration/geo/replication/location_aware_git_url.md

@@ -37,7 +37,7 @@ In any case, you require:
 - A Route53 Hosted Zone managing your domain.
 
 If you have not yet setup a Geo **primary** node and **secondary** node, please consult
-[the Geo setup instructions](https://docs.gitlab.com/ee/administration/geo/replication/#setup-instructions).
+[the Geo setup instructions](index.md#setup-instructions).
 
 ## Create a traffic policy
 

doc/administration/geo/replication/troubleshooting.md

@@ -244,8 +244,8 @@ sudo gitlab-rake gitlab:geo:check
 
     When performing a Postgres major version (9 > 10) update this is expected. Follow:
 
-    - [initiate-the-replication-process](https://docs.gitlab.com/ee/administration/geo/replication/database.html#step-3-initiate-the-replication-process)
-    - [Geo database has an outdated FDW remote schema](https://docs.gitlab.com/ee/administration/geo/replication/troubleshooting.html#geo-database-has-an-outdated-fdw-remote-schema-error)
+    - [initiate-the-replication-process](database.md#step-3-initiate-the-replication-process)
+    - [Geo database has an outdated FDW remote schema](troubleshooting.md#geo-database-has-an-outdated-fdw-remote-schema-error)
 
 ## Fixing replication errors
 
@@ -494,7 +494,7 @@ If you encounter this message when running `gitlab-rake geo:set_secondary_as_pri
 or `gitlab-ctl promote-to-primary-node`, either:
 
 - Enter a Rails console and run:
-  
+
   ```ruby
   Rails.application.load_tasks; nil
   Gitlab::Geo.expire_cache_keys!([:primary_node, :current_node])

doc/administration/uploads.md

@@ -63,7 +63,7 @@ For source installations the following settings are nested under `uploads:` and
 |---------|-------------|---------|
 | `enabled` | Enable/disable object storage | `false` |
 | `remote_directory` | The bucket name where Uploads will be stored| |
-| `direct_upload` | Set to true to remove Unicorn from the Upload path. Workhorse handles the actual Artifact Upload to Object Storage while Unicorn does minimal processing to keep track of the upload. There is no need for local shared storage. The option may be removed if support for a single storage type for all files is introduced. Read more on [what the direct_upload setting means](https://docs.gitlab.com/ee/development/uploads.html#what-does-the-direct_upload-setting-mean). | `false` |
+| `direct_upload` | Set to true to remove Unicorn from the Upload path. Workhorse handles the actual Artifact Upload to Object Storage while Unicorn does minimal processing to keep track of the upload. There is no need for local shared storage. The option may be removed if support for a single storage type for all files is introduced. Read more on [direct upload](../development/uploads.md#direct-upload). | `false` |
 | `background_upload` | Set to false to disable automatic upload. Option may be removed once upload is direct to S3 (if `direct_upload` is set to `true` it will override `background_upload`) | `true` |
 | `proxy_download` | Set to true to enable proxying all files served. Option allows to reduce egress traffic as this allows clients to download directly from remote storage instead of proxying all data | `false` |
 | `connection` | Various connection options described below | |

doc/development/documentation/styleguide.md

@@ -580,21 +580,15 @@ do not use this option until further notice.
 
 ### Links to internal documentation
 
-- To link to internal documentation, use relative links, not full URLs.
+- To link to internal documentation, use relative links, not absolute URLs.
   Use `../` to navigate to high-level directories. Links should not refer to root.
 
   Don't:
 
-  ```md
-  [Geo Troubleshooting](https://docs.gitlab.com/ee/administration/geo/replication/troubleshooting.html)
-  [Geo Troubleshooting](/ee/administration/geo/replication/troubleshooting.md)
-  ```
-
-  Do:
+  - `https://docs.gitlab.com/ee/administration/geo/replication/troubleshooting.html`
+  - `/ee/administration/geo/replication/troubleshooting.md`
 
-  ```md
-  [Geo Troubleshooting](../../geo/replication/troubleshooting.md)
-  ```
+  Do: `../../geo/replication/troubleshooting.md`
 
 - Always add the file name `file.md` at the end of the link with the `.md` extension, not `.html`.
 

doc/development/issuable-like-models.md

 # Issuable-like Rails models utilities
 
 GitLab Rails codebase contains several models that hold common functionality and behave similarly to
-[Issues](https://docs.gitlab.com/ee/user/project/issues/). Other examples of "issuables"
-are [Merge Requests](https://docs.gitlab.com/ee/user/project/merge_requests/) and
-[Epics](https://docs.gitlab.com/ee/user/group/epics/).
+[Issues](../user/project/issues/index.md). Other examples of "issuables"
+are [Merge Requests](../user/project/merge_requests/index.md) and
+[Epics](../user/group/epics/index.md).
 
 This guide accumulates guidelines on working with such Rails models.
 

doc/development/merge_request_performance_guidelines.md

@@ -115,7 +115,7 @@ data migration. Migrating millions of rows will always be troublesome and
 can have a negative impact on the application.
 
 To better understand how to get help with the query plan reviews
-read this section on [how to prepare the merge request for a database review](https://docs.gitlab.com/ee/development/database_review.html#how-to-prepare-the-merge-request-for-a-database-review).
+read this section on [how to prepare the merge request for a database review](database_review.md#how-to-prepare-the-merge-request-for-a-database-review).
 
 ## Query Counts
 
@@ -199,7 +199,7 @@ This could result in Puma/Unicorn timeout and should be avoided at all cost.
 You should set a reasonable timeout, gracefully handle exceptions and surface the
 errors in UI or logging internally.
 
-Using [`ReactiveCaching`](https://docs.gitlab.com/ee/development/utilities.html#reactivecaching) is one of the best solutions to fetch external data.
+Using [`ReactiveCaching`](utilities.md#reactivecaching) is one of the best solutions to fetch external data.
 
 ## Keep database transaction minimal
 
@@ -396,4 +396,4 @@ Performance deficiencies should be addressed right away after we merge initial
 changes.
 
 Read more about when and how feature flags should be used in
-[Feature flags in GitLab development](https://docs.gitlab.com/ee/development/feature_flags/process.html#feature-flags-in-gitlab-development).
+[Feature flags in GitLab development](feature_flags/process.md#feature-flags-in-gitlab-development).

doc/development/testing_guide/testing_migrations_guide.md

@@ -49,7 +49,7 @@ require Rails.root.join('db', 'post_migrate', '20170526185842_migrate_pipeline_s
 #### `table`
 
 Use the `table` helper to create a temporary `ActiveRecord::Base`-derived model
-for a table. [FactoryBot](https://docs.gitlab.com/ee/development/testing_guide/best_practices.html#factories)
+for a table. [FactoryBot](best_practices.md#factories)
 **should not** be used to create data for migration specs. For example, to
 create a record in the `projects` table:
 

doc/integration/elasticsearch.md

@@ -511,7 +511,7 @@ Here are some common pitfalls and how to overcome them:
   If you see `Elasticsearch::Model::Response::Records`, you are using Elasticsearch.
 
   NOTE: **Note**:
-  The above instructions are used to verify that GitLab is using Elasticsearch only when indexing all namespaces. This is not to be used for scenarios that only index a [subset of namespaces](https://docs.gitlab.com/ee/integration/elasticsearch.html#limiting-namespaces-and-projects).
+  The above instructions are used to verify that GitLab is using Elasticsearch only when indexing all namespaces. This is not to be used for scenarios that only index a [subset of namespaces](#limiting-namespaces-and-projects).
 
 - **I updated GitLab and now I can't find anything**
 
@@ -534,7 +534,7 @@ Here are some common pitfalls and how to overcome them:
   ```
 
   NOTE: **Note**:
-  The above instructions are not to be used for scenarios that only index a [subset of namespaces](https://docs.gitlab.com/ee/integration/elasticsearch.html#limiting-namespaces-and-projects).
+  The above instructions are not to be used for scenarios that only index a [subset of namespaces](#limiting-namespaces-and-projects).
 
   See [Elasticsearch Index Scopes](#elasticsearch-index-scopes) for more information on searching for specific types of data.
 
@@ -597,7 +597,7 @@ Here are some common pitfalls and how to overcome them:
   AWS has [fixed limits](https://docs.aws.amazon.com/elasticsearch-service/latest/developerguide/aes-limits.html)
   for this setting ("Maximum Size of HTTP Request Payloads"), based on the size of
   the underlying instance.
-  
+
 - **My single node Elasticsearch cluster status never goes from `yellow` to `green` even though everything seems to be running properly**
 
   **For a single node Elasticsearch cluster the functional cluster health status will be yellow** (will never be green) because the primary shard is allocated but replicas can not be as there is no other node to which Elasticsearch can assign a replica. This also applies if you are using using the
@@ -614,7 +614,7 @@ Here are some common pitfalls and how to overcome them:
     }
   }'
   ```
-  
+
 - **I'm getting a `health check timeout: no Elasticsearch node available` error in Sidekiq during the indexing process**
 
    ```

doc/subscriptions/index.md

@@ -243,7 +243,7 @@ If you reach your limit, you can [purchase additional CI minutes](#extra-shared-
 
 ##### How pipeline quota usage is calculated
 
-Pipeline quota usage is calculated as the sum of the duration of each individual job. This is slightly different to how pipeline _duration_ is [calculated](https://docs.gitlab.com/ee/ci/pipelines.html#how-pipeline-duration-is-calculated). Pipeline quota usage doesn't consider the intersection of jobs.
+Pipeline quota usage is calculated as the sum of the duration of each individual job. This is slightly different to how pipeline _duration_ is [calculated](../ci/pipelines.md#how-pipeline-duration-is-calculated). Pipeline quota usage doesn't consider the intersection of jobs.
 
 A simple example is:
 

doc/user/project/clusters/serverless/aws.md

@@ -16,7 +16,7 @@ like:
 - Working with secrets.
 - Setting up CORS.
 
-Alternatively, you can quickly [create a new project with a template](https://docs.gitlab.com/ee/gitlab-basics/create-project.html#project-templates). The [`Serverless Framework/JS` template](https://gitlab.com/gitlab-org/project-templates/serverless-framework/) already includes all parts described below.
+Alternatively, you can quickly [create a new project with a template](../../../../gitlab-basics/create-project.md#project-templates). The [`Serverless Framework/JS` template](https://gitlab.com/gitlab-org/project-templates/serverless-framework/) already includes all parts described below.
 
 ## Example
 
@@ -282,6 +282,6 @@ The example code is available:
 - As a [cloneable repository](https://gitlab.com/gitlab-org/serverless/examples/serverless-framework-js).
 - In a version with [tests and secret variables](https://gitlab.com/gitlab-org/project-templates/serverless-framework/).
 
-You can also use a [template](https://docs.gitlab.com/ee/gitlab-basics/create-project.html#project-templates)
+You can also use a [template](../../../../gitlab-basics/create-project.md#project-templates)
 (based on the version with tests and secret variables) from within the GitLab UI (see
 the `Serverless Framework/JS` template).

doc/user/project/push_options.md

@@ -7,7 +7,7 @@ type: reference
 > [Introduced](https://gitlab.com/gitlab-org/gitlab-foss/-/merge_requests/15643) in GitLab 11.7.
 
 GitLab supports using client-side [Git push options](https://git-scm.com/docs/git-push#Documentation/git-push.txt--oltoptiongt)
-to perform various actions at the same time as pushing changes. Additionally, [Push Rules](https://docs.gitlab.com/ee/push_rules/push_rules.html) offer server-side control and enforcement options.
+to perform various actions at the same time as pushing changes. Additionally, [Push Rules](../../push_rules/push_rules.md) offer server-side control and enforcement options.
 
 Currently, there are push options available for: