Geo: Deprecate source installations instructions?

doc/administration/geo/replication/configuration_source.md

 # Geo configuration (source)
 
 NOTE: **Note:**
-This is the documentation for installations from source. For installations
+This documentation applies to GitLab source installations. In GitLab 11.5, this documentation was deprecated and will be removed in a future release.
+Please consider [migrating to GitLab Omnibus install](https://docs.gitlab.com/omnibus/update/convert_to_omnibus.html). For installations
 using the Omnibus GitLab packages, follow the
 [**Omnibus Geo nodes configuration**][configuration] guide.
 
@@ -122,7 +123,7 @@ replicating missing data from the primary in a process known as backfill.
 Meanwhile, the primary node will start to notify the secondary of any changes, so
 that the secondary can act on those notifications immediately.
 
-Make sure the secondary instance is running and accessible. 
+Make sure the secondary instance is running and accessible.
 You can login to the secondary node with the same credentials as used in the primary.
 
 ### Step 4. (Optional) Enabling hashed storage (from GitLab 10.0)

doc/administration/geo/replication/database_source.md

 # Geo database replication (source)
 
 NOTE: **Note:**
-This is the documentation for installations from source. For installations
+This documentation applies to GitLab source installations. In GitLab 11.5, this documentation was deprecated and will be removed in a future release.
+Please consider [migrating to GitLab Omnibus install](https://docs.gitlab.com/omnibus/update/convert_to_omnibus.html). For installations
 using the Omnibus GitLab packages, follow the
 [**database replication for Omnibus GitLab**][database] guide.
 

doc/administration/geo/replication/index.md

@@ -163,7 +163,10 @@ If you installed GitLab using the Omnibus packages (highly recommended):
 1. Optional: [Configure a secondary LDAP server](../../auth/ldap.md) for the secondary node. See [notes on LDAP](#ldap).
 1. [Follow the "Using a Geo Server" guide](using_a_geo_server.md).
 
-### Using GitLab installed from source
+### Using GitLab installed from source (Deprecated)
+
+NOTE: **Note:**
+In GitLab 11.5, support for using Geo in GitLab source installations was deprecated and will be removed in a future release. Please consider [migrating to GitLab Omnibus install](https://docs.gitlab.com/omnibus/update/convert_to_omnibus.html).
 
 If you installed GitLab from source:
 
@@ -183,7 +186,7 @@ After installing GitLab on the secondary nodes and performing the initial config
 For information on configuring Geo, see:
 
 - [Geo configuration (GitLab Omnibus)](configuration.md).
-- [Geo configuration (source)](configuration_source.md).
+- [Geo configuration (source)](configuration_source.md). Configuring Geo in GitLab source installations was **deprecated** in GitLab 11.5.
 
 ### Updating Geo
 

ee/changelogs/unreleased/5736-geo-deprecate-source-installations-instructions.yml

+---
+title: 'Geo: Deprecate source installations instructions'
+merge_request: 8134
+author:
+type: changed