Geo migrations settings are included by default

Changelog: changed
EE: true

config/application.rb

@@ -69,18 +69,19 @@ module Gitlab
     require_dependency Rails.root.join('lib/gitlab/middleware/handle_malformed_strings')
     require_dependency Rails.root.join('lib/gitlab/middleware/rack_multipart_tempfile_factory')
     require_dependency Rails.root.join('lib/gitlab/runtime')
-    require_dependency Rails.root.join('lib/gitlab/patch/legacy_database_config')
+    require_dependency Rails.root.join('lib/gitlab/patch/database_config')
     require_dependency Rails.root.join('lib/gitlab/exceptions_app')
 
     config.exceptions_app = Gitlab::ExceptionsApp.new(Rails.public_path)
 
-    # To be removed in 15.0
-    # This preload is needed to convert legacy `database.yml`
-    # from `production: adapter: postgresql`
-    # into a `production: main: adapter: postgresql`
-    unless Gitlab::Utils.to_boolean(ENV['SKIP_DATABASE_CONFIG_VALIDATION'], default: false)
-      config.class.prepend(::Gitlab::Patch::LegacyDatabaseConfig)
-    end
+    # This preload is required to:
+    #
+    # 1. Convert legacy `database.yml`;
+    # 2. Include Geo post-deployment migrations settings;
+    #
+    # TODO: In 15.0, this preload can be wrapped in a Gitlab.ee block
+    #       since we don't need to convert legacy `database.yml` anymore.
+    config.class.prepend(::Gitlab::Patch::DatabaseConfig)
 
     # Settings in config/environments/* take precedence over those specified here.
     # Application configuration should go into files in config/initializers

lib/gitlab/patch/legacy_database_config.rb → lib/gitlab/patch/database_config.rb

@@ -28,7 +28,7 @@
 
 module Gitlab
   module Patch
-    module LegacyDatabaseConfig
+    module DatabaseConfig
       extend ActiveSupport::Concern
 
       prepended do
@@ -73,23 +73,34 @@ module Gitlab
         @uses_legacy_database_config = false # rubocop:disable Gitlab/ModuleWithInstanceVariables
 
         super.to_h do |env, configs|
-          # This check is taken from Rails where the transformation
-          # of a flat database.yml is done into `primary:`
-          # https://github.com/rails/rails/blob/v6.1.4/activerecord/lib/active_record/database_configurations.rb#L169
-          if configs.is_a?(Hash) && !configs.all? { |_, v| v.is_a?(Hash) }
-            configs = { "main" => configs }
-
-            @uses_legacy_database_config = true # rubocop:disable Gitlab/ModuleWithInstanceVariables
+          # TODO: To be removed in 15.0. See https://gitlab.com/gitlab-org/gitlab/-/issues/338182
+          # This preload is needed to convert legacy `database.yml`
+          # from `production: adapter: postgresql`
+          # into a `production: main: adapter: postgresql`
+          unless Gitlab::Utils.to_boolean(ENV['SKIP_DATABASE_CONFIG_VALIDATION'], default: false)
+            # This check is taken from Rails where the transformation
+            # of a flat database.yml is done into `primary:`
+            # https://github.com/rails/rails/blob/v6.1.4/activerecord/lib/active_record/database_configurations.rb#L169
+            if configs.is_a?(Hash) && !configs.all? { |_, v| v.is_a?(Hash) }
+              configs = { "main" => configs }
+
+              @uses_legacy_database_config = true # rubocop:disable Gitlab/ModuleWithInstanceVariables
+            end
           end
 
-          if Gitlab.ee? && File.exist?(Rails.root.join("config/database_geo.yml"))
-            migrations_paths = ["ee/db/geo/migrate"]
-            migrations_paths << "ee/db/geo/post_migrate" unless ENV['SKIP_POST_DEPLOYMENT_MIGRATIONS']
+          if Gitlab.ee?
+            if !configs.key?("geo") && File.exist?(Rails.root.join("config/database_geo.yml"))
+              configs["geo"] = Rails.application.config_for(:database_geo).stringify_keys
+            end
+
+            if configs.key?("geo")
+              migrations_paths = Array(configs["geo"]["migrations_paths"])
+              migrations_paths << "ee/db/geo/migrate" if migrations_paths.empty?
+              migrations_paths << "ee/db/geo/post_migrate" unless ENV['SKIP_POST_DEPLOYMENT_MIGRATIONS']
 
-            configs["geo"] =
-              Rails.application.config_for(:database_geo)
-                .merge(migrations_paths: migrations_paths, schema_migrations_path: "ee/db/geo/schema_migrations")
-                .stringify_keys
+              configs["geo"]["migrations_paths"] = migrations_paths.uniq
+              configs["geo"]["schema_migrations_path"] = "ee/db/geo/schema_migrations" if configs["geo"]["schema_migrations_path"].blank?
+            end
           end
 
           [env, configs]

spec/lib/gitlab/patch/legacy_database_config_spec.rb → spec/lib/gitlab/patch/database_config_spec.rb

@@ -2,7 +2,7 @@
 
 require 'spec_helper'
 
-RSpec.describe Gitlab::Patch::LegacyDatabaseConfig do
+RSpec.describe Gitlab::Patch::DatabaseConfig do
   it 'module is included' do
     expect(Rails::Application::Configuration).to include(described_class)
   end