Merge branch 'close_database_connections_again_after_set_routes_reloader_hook' into 'master'

Better fix for PG::ObjectInUse error when dropping databases

See merge request gitlab-org/gitlab!85006

config/application.rb

@@ -517,6 +517,14 @@ module Gitlab
       end
     end
 
+    # We run the contents of active_record.clear_active_connections again
+    # because we connect to database from routes
+    # https://github.com/rails/rails/blob/fdf840f69a2e33d78a9d40b91d9b7fddb76711e9/activerecord/lib/active_record/railtie.rb#L308
+    initializer :clear_active_connections_again, after: :set_routes_reloader_hook do
+      ActiveRecord::Base.clear_active_connections!
+      ActiveRecord::Base.flush_idle_connections!
+    end
+
     # DO NOT PLACE ANY INITIALIZERS AFTER THIS.
     config.after_initialize do
       # on_master_start yields immediately in unclustered environments and runs

lib/tasks/gitlab/db.rake

@@ -233,14 +233,6 @@ namespace :gitlab do
       # :nocov:
     end
 
-    desc "Clear all connections"
-    task :clear_all_connections do
-      ActiveRecord::Base.clear_all_connections!
-    end
-
-    Rake::Task['db:test:purge'].enhance(['gitlab:db:clear_all_connections'])
-    Rake::Task['db:drop'].enhance(['gitlab:db:clear_all_connections'])
-
     # During testing, db:test:load restores the database schema from scratch
     # which does not include dynamic partitions. We cannot rely on application
     # initializers here as the application can continue to run while

lib/tasks/gitlab/db/validate_config.rake

@@ -6,7 +6,7 @@ namespace :gitlab do
   namespace :db do
     desc 'Validates `config/database.yml` to ensure a correct behavior is configured'
     task validate_config: :environment do
-      should_reconnect = ActiveRecord::Base.connection_pool.active_connection?
+      original_db_config = ActiveRecord::Base.connection_db_config
 
       # The include_replicas: is a legacy name to fetch all hidden entries (replica: true or database_tasks: false)
       # Once we upgrade to Rails 7.x this should be changed to `include_hidden: true`
@@ -97,9 +97,7 @@ namespace :gitlab do
       end
 
     ensure
-      if should_reconnect
-        ActiveRecord::Base.establish_connection(ActiveRecord::Tasks::DatabaseTasks.env.to_sym) # rubocop: disable Database/EstablishConnection
-      end
+      ActiveRecord::Base.establish_connection(original_db_config) # rubocop: disable Database/EstablishConnection
     end
 
     Rake::Task['db:migrate'].enhance(['gitlab:db:validate_config'])

spec/tasks/gitlab/db/validate_config_rake_spec.rb

@@ -46,6 +46,12 @@ RSpec.describe 'gitlab:db:validate_config', :silence_stdout do
         expect { run_rake_task('gitlab:db:validate_config') }.not_to raise_error
       end
 
+      it 'always re-establishes ActiveRecord::Base connection to main config' do
+        run_rake_task('gitlab:db:validate_config')
+
+        expect(ActiveRecord::Base.connection_db_config.configuration_hash).to include(main_database_config) # rubocop: disable Database/MultipleDatabases
+      end
+
       it 'if GITLAB_VALIDATE_DATABASE_CONFIG is set' do
         stub_env('GITLAB_VALIDATE_DATABASE_CONFIG', '1')
         allow(Gitlab).to receive(:dev_or_test_env?).and_return(false)
@@ -78,6 +84,12 @@ RSpec.describe 'gitlab:db:validate_config', :silence_stdout do
         expect { run_rake_task('gitlab:db:validate_config') }.to raise_error(match)
       end
 
+      it 'always re-establishes ActiveRecord::Base connection to main config' do
+        expect { run_rake_task('gitlab:db:validate_config') }.to raise_error(match)
+
+        expect(ActiveRecord::Base.connection_db_config.configuration_hash).to include(main_database_config) # rubocop: disable Database/MultipleDatabases
+      end
+
       it 'if GITLAB_VALIDATE_DATABASE_CONFIG=1' do
         stub_env('GITLAB_VALIDATE_DATABASE_CONFIG', '1')
 

spec/tasks/gitlab/db_rake_spec.rb

@@ -20,14 +20,6 @@ RSpec.describe 'gitlab:db namespace rake task', :silence_stdout do
     allow(Rake::Task['db:seed_fu']).to receive(:invoke).and_return(true)
   end
 
-  describe 'clear_all_connections' do
-    it 'calls clear_all_connections!' do
-      expect(ActiveRecord::Base).to receive(:clear_all_connections!)
-
-      run_rake_task('gitlab:db:clear_all_connections')
-    end
-  end
-
   describe 'mark_migration_complete' do
     context 'with a single database' do
       let(:main_model) { ActiveRecord::Base }