Remove references of MySQL and update docs

Signed-off-by: Balasankar "Balu" C <balasankar@gitlab.com>

README.md

@@ -78,7 +78,7 @@ For using an existing Nginx, Passenger, or Apache webserver see [doc/settings/ng
 ##### Using a non-packaged PostgreSQL database management server
-To connect to an external PostgreSQL or MySQL DBMS see [doc/settings/database.md](doc/settings/database.md) (MySQL support in the Omnibus Packages is Enterprise Only).
+To connect to an external PostgreSQL DBMS see [doc/settings/database.md](doc/settings/database.md)
 ##### Using a non-packaged Redis instance
@@ -290,10 +290,6 @@ See [doc/settings/logs.md](doc/settings/logs.md#logrotate).
 See [doc/settings/logs.md](doc/settings/logs.md#udp-log-shipping-gitlab-enterprise-edition-only)
-## Using a MySQL database management server (Enterprise Edition only)
-
-See [doc/settings/database.md](doc/settings/database.md).
-
 ### Create a user and database for GitLab
 See [doc/settings/database.md](doc/settings/database.md).

config/software/gitlab-rails.rb

@@ -84,6 +84,8 @@ build do
   end
   bundle_without = %w(development test)
+  # TODO: Remove if mysql group is removed from gitlab-ce|ee bundle
+  # https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/29608
   bundle_without << 'mysql' unless EE
   bundle 'config build.rugged --no-use-system-libraries', env: env
   bundle 'config build.gpgme --use-system-libraries', env: env

doc/settings/configuration.md

@@ -641,7 +641,7 @@ For using an existing Nginx, Passenger, or Apache webserver see [doc/settings/ng
 ## Using a non-packaged PostgreSQL database management server
-To connect to an external PostgreSQL or MySQL DBMS see [doc/settings/database.md](database.md) (MySQL support in the Omnibus Packages is Enterprise Only).
+To connect to an external PostgreSQL DBMS see [doc/settings/database.md](database.md)
 ## Using a non-packaged Redis instance

doc/settings/database.md

@@ -505,19 +505,6 @@ If you need to run an older version of PostgreSQL, you must downgrade GitLab to
 ## Troubleshooting
-### Set MySQL collation to UTF-8
-
-If you are hit by an error similar as described in [this issue][ee-245]
-(_Mysql2::Error: Incorrect string value (\`st_diffs\` field)_), you
-can change the collation of the faulty table with:
-
-```bash
-ALTER TABLE merge_request_diffs default character set = utf8 collate = utf8_unicode_ci;
-ALTER TABLE merge_request_diffs convert to character set utf8 collate utf8_unicode_ci;
-```
-
-In the above example the affected table is called `merge_request_diffs`.
-
 ### Connecting to the bundled PostgreSQL database
 If you need to connect to the bundled PostgreSQL database and are
@@ -534,10 +521,7 @@ or as a Postgres superuser:
 sudo gitlab-psql -d gitlabhq_production
 ```
-[ee-245]: https://gitlab.com/gitlab-org/gitlab-ee/issues/245 "MySQL collation issue"
 [rake-backup]: https://docs.gitlab.com/ce/raketasks/backup_restore.html#create-a-backup-of-the-gitlab-system "Backup raketask documentation"
 [Reconfigure GitLab]: https://docs.gitlab.com/ce/administration/restart_gitlab.html#omnibus-gitlab-reconfigure "Reconfigure GitLab"
 [rake-restore]: https://docs.gitlab.com/ce/raketasks/backup_restore.html#restore-a-previously-created-backup "Restore raketask documentation"
-[mysql-install]: https://docs.gitlab.com/ce/install/database_mysql.html "MySQL documentation"
 [database requirements document]: https://docs.gitlab.com/ce/install/requirements.html#database
-[mysql-migrate]: https://docs.gitlab.com/ce/update/mysql_to_postgresql.html

doc/update/README.md

@@ -202,9 +202,8 @@ step to find the current GitLab version and then follow the steps in
 NOTE: **Note:**
 This is only available in GitLab 9.1.0 or newer. Skipping restarts during reconfigure with `/etc/gitlab/skip-auto-reconfigure` was added in [version 10.6](https://gitlab.com/gitlab-org/omnibus-gitlab/merge_requests/2270). If running a version prior to 10.6, you will need to create `/etc/gitlab/skip-auto-migrations`.
-It's possible to upgrade to a newer version of
-GitLab without having to take your GitLab instance offline. This can only be
-done if you are using PostgreSQL. If you are using MySQL you will still need downtime when upgrading.
+It's possible to upgrade to a newer version of GitLab without having to take
+your GitLab instance offline.
 Verify that you can upgrade with no downtime by checking the
 [Upgrading without downtime section](https://docs.gitlab.com/ee/update/README.html#upgrading-without-downtime) of the update document.

doc/update/convert_to_omnibus.md

@@ -102,17 +102,12 @@ settings in `gitlab.rb`, see the [settings docs](../settings/README.md).
 ## Upgrading from non-Omnibus MySQL to an Omnibus installation (version 6.8+)
-If your non-Omnibus installation is using MySQL, you have two options since
-the Omnibus installation is using PostgreSQL.
-**Option 1**
-
-The Omnibus packages for Enterprise Edition can be configured to use an external
-[non-packaged MySQL database](../settings/database.md#using-a-mysql-database-management-server-enterprise-edition-only).
-
-**Option 2**
-
-Convert to PostgreSQL and use the built-in server:
+Starting with GitLab 12.1, PostgreSQL is the only support database management
+system. So, if your non-Omnibus installation is running a GitLab version before
+12.1 and is using MySQL, you will have to migrate to PostgreSQL before upgrading
+to 12.1.
+To convert to PostgreSQL and use the built-in server, follow the steps:
 - [Create a backup of the non-Omnibus MySQL installation](https://docs.gitlab.com/ce/raketasks/backup_restore.html#creating-a-backup-of-the-gitlab-system)
 - [Export and convert the existing MySQL database in the GitLab backup file](https://docs.gitlab.com/ee/update/mysql_to_postgresql.html#converting-a-gitlab-backup-file-from-mysql-to-postgres)