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, 12 insertions, 0 deletions

diff --git a/spec/services/users/activity_service_spec.rb b/spec/services/users/activity_service_spec.rb
index fef4da0c76e..17eabad73be 100644
--- a/spec/services/users/activity_service_spec.rb
+++ b/spec/services/users/activity_service_spec.rb
@@ -38,6 +38,18 @@ describe Users::ActivityService do
         end
       end
     end
+
+    context 'when in GitLab read-only instance' do
+      before do
+        allow(Gitlab::Database).to receive(:read_only?).and_return(true)
+      end
+
+      it 'does not update last_activity_at' do
+        service.execute
+
+        expect(last_hour_user_ids).to eq([])
+      end
+    end
   end
 
   def last_hour_user_ids