Gitlab::Database.read_only? works correctly for EE version (specs included)

changelogs/unreleased-ee/3876-can-push-code-to-geo-secondaries.yml

+---
+title: 'Geo: read-only safeguards was not working on Secondary node'
+merge_request: 3227
+author:
+type: fixed

ee/lib/ee/gitlab/database.rb

-module EE
-  module Gitlab
-    module Database
-      def self.read_only?
-        raise NotImplementedError unless defined?(super)
-
-        Gitlab::Geo.secondary? || super
-      end
-    end
-  end
-end

lib/gitlab/database.rb

 module Gitlab
   module Database
-    extend ::EE::Gitlab::Database
-
     # The max value of INTEGER type is the same between MySQL and PostgreSQL:
     # https://www.postgresql.org/docs/9.2/static/datatype-numeric.html
     # http://dev.mysql.com/doc/refman/5.7/en/integer-types.html
@@ -33,7 +31,7 @@ module Gitlab
 
     # Overridden in EE
     def self.read_only?
-      false
+      Gitlab::Geo.secondary?
     end
 
     def self.read_write?

lib/tasks/migrate/setup_postgresql.rake

-require Rails.root.join('ee/lib/ee/gitlab/database')
 require Rails.root.join('lib/gitlab/database')
 require Rails.root.join('lib/gitlab/database/migration_helpers')
 require Rails.root.join('db/migrate/20151007120511_namespaces_projects_path_lower_indexes')

spec/lib/gitlab/database_spec.rb

@@ -273,4 +273,35 @@ describe Gitlab::Database do
       expect(config['prepared_statements']).to eq(false)
     end
   end
+
+  describe '.read_only?' do
+    context 'with Geo enabled' do
+      before do
+        allow(Gitlab::Geo).to receive(:enabled?) { true }
+        allow(Gitlab::Geo).to receive(:current_node) { geo_node }
+      end
+
+      context 'is Geo secondary node' do
+        let(:geo_node) { create(:geo_node) }
+
+        it 'returns true' do
+          expect(described_class.read_only?).to be_truthy
+        end
+      end
+
+      context 'is Geo primary node' do
+        let(:geo_node) { create(:geo_node, :primary) }
+
+        it 'returns false when is Geo primary node' do
+          expect(described_class.read_only?).to be_falsey
+        end
+      end
+    end
+
+    context 'with Geo disabled' do
+      it 'returns false' do
+        expect(described_class.read_only?).to be_falsey
+      end
+    end
+  end
 end