Rails5: Fix the check whether the database is in read-only mode

Rails 5 returns true/false instead of a string 't' or 'f'.

ee/changelogs/unreleased/8581-geo-the-geo-nodes-admin-page-display-secondary-database-state-incorrectly.yml

+---
+title: 'Rails 5: Fix the check whether the database is in read-only mode'
+merge_request: 8594
+author:
+type: fixed

lib/gitlab/database.rb

@@ -51,9 +51,11 @@ module Gitlab
     # check whether the underlying database is in read-only mode
     def self.db_read_only?
       if postgresql?
-        ActiveRecord::Base.connection.execute('SELECT pg_is_in_recovery()')
-          .first
-          .fetch('pg_is_in_recovery') == 't'
+        pg_is_in_recovery =
+          ActiveRecord::Base.connection.execute('SELECT pg_is_in_recovery()')
+            .first.fetch('pg_is_in_recovery')
+
+        Gitlab::Utils.to_boolean(pg_is_in_recovery)
       else
         false
       end

spec/lib/gitlab/database_spec.rb

@@ -495,7 +495,7 @@ describe Gitlab::Database do
     context 'when using PostgreSQL' do
       before do
         allow(ActiveRecord::Base.connection).to receive(:execute).and_call_original
-        expect(described_class).to receive(:postgresql?).and_return(true)
+        allow(described_class).to receive(:postgresql?).and_return(true)
       end
 
       it 'detects a read only database' do
@@ -504,11 +504,25 @@ describe Gitlab::Database do
         expect(described_class.db_read_only?).to be_truthy
       end
 
+      # TODO: remove rails5-only tag after removing rails4 tests
+      it 'detects a read only database', :rails5 do
+        allow(ActiveRecord::Base.connection).to receive(:execute).with('SELECT pg_is_in_recovery()').and_return([{ "pg_is_in_recovery" => true }])
+
+        expect(described_class.db_read_only?).to be_truthy
+      end
+
       it 'detects a read write database' do
         allow(ActiveRecord::Base.connection).to receive(:execute).with('SELECT pg_is_in_recovery()').and_return([{ "pg_is_in_recovery" => "f" }])
 
         expect(described_class.db_read_only?).to be_falsey
       end
+
+      # TODO: remove rails5-only tag after removing rails4 tests
+      it 'detects a read write database', :rails5 do
+        allow(ActiveRecord::Base.connection).to receive(:execute).with('SELECT pg_is_in_recovery()').and_return([{ "pg_is_in_recovery" => false }])
+
+        expect(described_class.db_read_only?).to be_falsey
+      end
     end
 
     context 'when using MySQL' do