Database work to support inherited templates on service desk

Allows to save template project id on database to user
inherited templates on service desk.

Changelog: added

db/migrate/20210818193008_add_file_template_project_to_service_desk_settings.rb

+# frozen_string_literal: true
+
+class AddFileTemplateProjectToServiceDeskSettings < ActiveRecord::Migration[6.1]
+  include Gitlab::Database::MigrationHelpers
+
+  def change
+    add_column :service_desk_settings, :file_template_project_id, :bigint, null: true
+  end
+end

db/migrate/20210818200455_add_file_template_project_foreign_key_to_service_desk_settings.rb

+# frozen_string_literal: true
+
+class AddFileTemplateProjectForeignKeyToServiceDeskSettings < ActiveRecord::Migration[6.1]
+  include Gitlab::Database::MigrationHelpers
+
+  disable_ddl_transaction!
+
+  INDEX_NAME = 'index_service_desk_settings_on_file_template_project_id'
+
+  def up
+    add_concurrent_index :service_desk_settings, :file_template_project_id, name: INDEX_NAME
+    add_concurrent_foreign_key :service_desk_settings, :projects, column: :file_template_project_id, on_delete: :nullify
+  end
+
+  def down
+    with_lock_retries do
+      remove_foreign_key_if_exists :service_desk_settings, column: :file_template_project_id
+    end
+
+    remove_concurrent_index_by_name :service_desk_settings, name: INDEX_NAME
+  end
+end

db/schema_migrations/20210818193008

+d24d10134d661728dbe688da2b90da55c584627ca764a6cc4604631f8a5fa334
\ No newline at end of file

db/schema_migrations/20210818200455

+25eb43de74e7eb158718b19d8cea5da2540507e96fcbe47d4829fa806e773308
\ No newline at end of file

db/structure.sql

@@ -18267,7 +18267,8 @@ CREATE TABLE service_desk_settings (
     project_id bigint NOT NULL,
     issue_template_key character varying(255),
     outgoing_name character varying(255),
-    project_key character varying(255)
+    project_key character varying(255),
+    file_template_project_id bigint
 );
 
 CREATE TABLE shards (
@@ -25277,6 +25278,8 @@ CREATE INDEX index_serverless_domain_cluster_on_pages_domain_id ON serverless_do
 
 CREATE INDEX index_service_desk_enabled_projects_on_id_creator_id_created_at ON projects USING btree (id, creator_id, created_at) WHERE (service_desk_enabled = true);
 
+CREATE INDEX index_service_desk_settings_on_file_template_project_id ON service_desk_settings USING btree (file_template_project_id);
+
 CREATE UNIQUE INDEX index_shards_on_name ON shards USING btree (name);
 
 CREATE UNIQUE INDEX index_site_profile_secret_variables_on_site_profile_id_and_key ON dast_site_profile_secret_variables USING btree (dast_site_profile_id, key);
@@ -26134,6 +26137,9 @@ ALTER TABLE ONLY clusters_applications_runners
 ALTER TABLE ONLY incident_management_escalation_rules
     ADD CONSTRAINT fk_0314ee86eb FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE;
 
+ALTER TABLE ONLY service_desk_settings
+    ADD CONSTRAINT fk_03afb71f06 FOREIGN KEY (file_template_project_id) REFERENCES projects(id) ON DELETE SET NULL;
+
 ALTER TABLE ONLY design_management_designs_versions
     ADD CONSTRAINT fk_03c671965c FOREIGN KEY (design_id) REFERENCES design_management_designs(id) ON DELETE CASCADE;
 

lib/gitlab/import_export/project/import_export.yml

@@ -297,6 +297,7 @@ excluded_attributes:
     - :integrated
   service_desk_setting:
     - :outgoing_name
+    - :file_template_project_id
   priorities:
     - :label_id
   events:

spec/requests/api/project_attributes.yml

@@ -149,6 +149,7 @@ build_service_desk_setting: # service_desk_setting
   unexposed_attributes:
     - project_id
     - issue_template_key
+    - file_template_project_id
     - outgoing_name
   remapped_attributes:
     project_key: service_desk_address