Create idea of read-only databasetc-geo-read-only-idea

In GitLab EE, a GitLab instance can be read-only (e.g. when it's a Geo
secondary node). But in GitLab CE it also might be useful to have the
"read-only" idea around. So port it back to GitLab CE.

Also having the principle of read-only in GitLab CE would hopefully
lead to less errors introduced, doing write operations when there
aren't allowed for read-only calls.

Closes gitlab-org/gitlab-ce#37534.

1 files changed, 9 insertions, 0 deletions

diff --git a/lib/gitlab/database.rb b/lib/gitlab/database.rb
index a6ec75da385..357f16936c6 100644
--- a/lib/gitlab/database.rb
+++ b/lib/gitlab/database.rb
@@ -29,6 +29,15 @@ module Gitlab
       adapter_name.casecmp('postgresql').zero?
     end
 
+    # Overridden in EE
+    def self.read_only?
+      false
+    end
+
+    def self.read_write?
+      !self.read_only?
+    end
+
     def self.version
       database_version.match(/\A(?:PostgreSQL |)([^\s]+).*\z/)[1]
     end