Inline batched migrations only in dev env

We keep the dev env inlining for convenience for now. Otherwise,
developers would have to run the rake task whenever a data migration had
been scheduled.

For test env, we don't want this. Primarily due to executing this in the
database testing pipeline - where we don't want to inline the full
migration (it can take a long time with data from GitLab.com).

Closes https://gitlab.com/gitlab-org/gitlab/-/issues/328755

lib/gitlab/database/migration_helpers.rb

@@ -1031,7 +1031,7 @@ module Gitlab
           [column, temporary_name]
         end
 
-        batched_migration = queue_batched_background_migration(
+        queue_batched_background_migration(
           'CopyColumnUsingBackgroundMigrationJob',
           table,
           primary_key,
@@ -1040,12 +1040,6 @@ module Gitlab
           job_interval: interval,
           batch_size: batch_size,
           sub_batch_size: sub_batch_size)
-
-        if perform_background_migration_inline?
-          # To ensure the schema is up to date immediately we perform the
-          # migration inline in dev / test environments.
-          Gitlab::Database::BackgroundMigration::BatchedMigrationRunner.new.run_entire_migration(batched_migration)
-        end
       end
 
       # Performs a concurrent column rename when using PostgreSQL.

lib/tasks/gitlab/db.rake

@@ -248,5 +248,19 @@ namespace :gitlab do
       ActiveRecord::Base.clear_cache!
       ActiveRecord::Migration.verbose = verbose_was
     end
+
+    desc 'Run all pending batched migrations'
+    task execute_batched_migrations: :environment do
+      Gitlab::Database::BackgroundMigration::BatchedMigration.active.queue_order.each do |migration|
+        Gitlab::AppLogger.info("Executing batched migration #{migration.id} inline")
+        Gitlab::Database::BackgroundMigration::BatchedMigrationRunner.new.run_entire_migration(migration)
+      end
+    end
+
+    # Only for development environments,
+    # we execute pending data migrations inline for convenience.
+    Rake::Task['db:migrate'].enhance do
+      Rake::Task['gitlab:db:execute_batched_migrations'].invoke if Rails.env.development?
+    end
   end
 end

spec/lib/gitlab/database/migration_helpers_spec.rb

@@ -1902,22 +1902,6 @@ RSpec.describe Gitlab::Database::MigrationHelpers do
           )
         end
       end
-
-      context 'when the migration should be performed inline' do
-        let(:columns) { column }
-
-        it 'calls the runner to run the entire migration' do
-          expect(model).to receive(:perform_background_migration_inline?).and_return(true)
-
-          expect_next_instance_of(Gitlab::Database::BackgroundMigration::BatchedMigrationRunner) do |scheduler|
-            expect(scheduler).to receive(:run_entire_migration) do |batched_migration|
-              expect(batched_migration).to eq(migration_relation.last)
-            end
-          end
-
-          model.backfill_conversion_of_integer_to_bigint(table, column, batch_size: 2, sub_batch_size: 1)
-        end
-      end
     end
   end
 

spec/tasks/gitlab/db_rake_spec.rb

@@ -348,6 +348,26 @@ RSpec.describe 'gitlab:db namespace rake task' do
     end
   end
 
+  describe '#execute_batched_migrations' do
+    subject { run_rake_task('gitlab:db:execute_batched_migrations') }
+
+    let(:migrations) { create_list(:batched_background_migration, 2) }
+    let(:runner) { instance_double('Gitlab::Database::BackgroundMigration::BatchedMigrationRunner') }
+
+    before do
+      allow(Gitlab::Database::BackgroundMigration::BatchedMigration).to receive_message_chain(:active, :queue_order).and_return(migrations)
+      allow(Gitlab::Database::BackgroundMigration::BatchedMigrationRunner).to receive(:new).and_return(runner)
+    end
+
+    it 'executes all migrations' do
+      migrations.each do |migration|
+        expect(runner).to receive(:run_entire_migration).with(migration)
+      end
+
+      subject
+    end
+  end
+
   def run_rake_task(task_name, arguments = '')
     Rake::Task[task_name].reenable
     Rake.application.invoke_task("#{task_name}#{arguments}")