Merge branch 'with-lock-retries-v2-no-op-if-enabled-already' into 'master'

Update with_lock_retries V2 helper to not nest WithLockRetries

See merge request gitlab-org/gitlab!70474

lib/gitlab/database/migration_helpers/v2.rb

@@ -70,7 +70,9 @@ module Gitlab
         # If the lock was not acquired within the retry period, a last attempt is made without using +lock_timeout+.
         #
         # In order to retry the block, the method wraps the block into a transaction.
-        # Note it cannot be used inside an already open transaction and will raise an error in that case.
+        #
+        # When called inside an open transaction it will execute the block directly if lock retries are enabled
+        # with `enable_lock_retries!` at migration level, otherwise it will raise an error.
         #
         # ==== Examples
         #   # Invoking without parameters
@@ -101,14 +103,19 @@ module Gitlab
         # * +env+ - [Hash] custom environment hash, see the example with `DISABLE_LOCK_RETRIES`
         def with_lock_retries(*args, **kwargs, &block)
           if transaction_open?
-            raise <<~EOF
+            if enable_lock_retries?
+              Gitlab::AppLogger.warn 'Lock retries already enabled, executing the block directly'
+              yield
+            else
+              raise <<~EOF
               #{__callee__} can not be run inside an already open transaction
 
               Use migration-level lock retries instead, see https://docs.gitlab.com/ee/development/migration_style_guide.html#retry-mechanism-when-acquiring-database-locks
-            EOF
+              EOF
+            end
+          else
+            super(*args, **kwargs.merge(allow_savepoints: false), &block)
           end
-
-          super(*args, **kwargs.merge(allow_savepoints: false), &block)
         end
 
         # Renames a column without requiring downtime.

spec/lib/gitlab/database/migration_helpers/v2_spec.rb

@@ -293,5 +293,33 @@ RSpec.describe Gitlab::Database::MigrationHelpers::V2 do
 
       model.with_lock_retries(env: env, logger: in_memory_logger) { }
     end
+
+    context 'when in transaction' do
+      before do
+        allow(model).to receive(:transaction_open?).and_return(true)
+      end
+
+      context 'when lock retries are enabled' do
+        before do
+          allow(model).to receive(:enable_lock_retries?).and_return(true)
+        end
+
+        it 'does not use Gitlab::Database::WithLockRetries and executes the provided block directly' do
+          expect(Gitlab::Database::WithLockRetries).not_to receive(:new)
+
+          expect(model.with_lock_retries(env: env, logger: in_memory_logger) { :block_result }).to eq(:block_result)
+        end
+      end
+
+      context 'when lock retries are not enabled' do
+        before do
+          allow(model).to receive(:enable_lock_retries?).and_return(false)
+        end
+
+        it 'raises an error' do
+          expect { model.with_lock_retries(env: env, logger: in_memory_logger) { } }.to raise_error /can not be run inside an already open transaction/
+        end
+      end
+    end
   end
 end