Geo: Implement a download to a temporary repo

app/models/geo/project_registry.rb

@@ -19,7 +19,7 @@ class Geo::ProjectRegistry < Geo::BaseRegistry
     where(
       arel_table[:repository_retry_at].lt(Time.now)
         .or(arel_table[:wiki_retry_at].lt(Time.now))
-        .or(arel_table[:wiki_retry_at].eq(nil))
+        .or(arel_table[:repository_retry_at].eq(nil))
         .or(arel_table[:wiki_retry_at].eq(nil))
     )
   end

app/services/geo/base_sync_service.rb

@@ -170,5 +170,24 @@ module Geo
     def last_synced_at
       registry.public_send("last_#{type}_synced_at") # rubocop:disable GitlabSecurity/PublicSend
     end
+
+    def disk_path_temp
+      "#{repository.disk_path}_temp"
+    end
+
+    def build_temporary_repository
+      gitlab_shell.add_repository(project.repository_storage, disk_path_temp)
+      repository.clone.tap{|repo| repo.disk_path = disk_path_temp}
+    end
+
+    def clean_up_temporary_repository
+      gitlab_shell.remove_repository(project.repository_storage_path, disk_path_temp)
+    end
+
+    def set_temp_repository_as_main
+      log_info("Setting newly downloaded #{type} as a main one")
+      gitlab_shell.remove_repository(project.repository_storage_path, repository.disk_path)
+      gitlab_shell.mv_repository(project.repository_storage_path, disk_path_temp, repository.disk_path)
+    end
   end
 end

app/services/geo/repository_sync_service.rb

-require 'tmpdir'
-
 module Geo
   class RepositorySyncService < BaseSyncService
+    include Gitlab::ShellAdapter
+
     self.type = :repository
 
     private
 
-    def sync_repository(with_backup = false)
-      fetch_project_repository(with_backup)
+    def sync_repository(redownload = false)
+      fetch_project_repository(redownload)
       expire_repository_caches
     end
 
-    def fetch_project_repository(with_backup)
+    def fetch_project_repository(redownload)
       log_info('Trying to fetch project repository')
       update_registry(started_at: DateTime.now)
 
-      if with_backup
-        log_info('Backup enabled')
-        actual_path = project.repository.path_to_repo
-        backup_path = File.join(Dir.mktmpdir, project.path)
-
-        # Creating a backup copy and removing the main repo
-        FileUtils.mv(actual_path, backup_path)
-      end
-
-      project.ensure_repository
-      fetch_geo_mirror(project.repository)
-
-      if with_backup
-        log_info('Removing backup copy as the repository was redownloaded successfully')
-        FileUtils.rm_rf(backup_path)
+      if redownload
+        log_info('Redownloading repository')
+        clean_up_temporary_repository
+        fetch_geo_mirror(build_temporary_repository)
+        set_temp_repository_as_main
+      else
+        project.ensure_repository
+        fetch_geo_mirror(project.repository)
       end
 
       update_registry(finished_at: DateTime.now)
@@ -44,12 +37,6 @@ module Geo
       log_error('Invalid repository', e)
       registry.update(force_to_redownload_repository: true)
       expire_repository_caches
-    ensure
-      # Backup can only exist if redownload was unsuccessful
-      if with_backup && File.exist?(backup_path)
-        FileUtils.rm_rf(actual_path)
-        FileUtils.mv(backup_path, actual_path)
-      end
     end
 
     def expire_repository_caches
@@ -60,5 +47,9 @@ module Geo
     def ssh_url_to_repo
       "#{primary_ssh_path_prefix}#{project.full_path}.git"
     end
+
+    def repository
+      project.repository
+    end
   end
 end

app/services/geo/wiki_sync_service.rb

 module Geo
   class WikiSyncService < BaseSyncService
+    include Gitlab::ShellAdapter
+
     self.type = :wiki
 
     private
 
-    def sync_repository(with_backup = false)
-      fetch_wiki_repository(with_backup)
+    def sync_repository(redownload = false)
+      fetch_wiki_repository(redownload)
     end
 
-    def fetch_wiki_repository(with_backup)
+    def fetch_wiki_repository(redownload)
       log_info('Fetching wiki repository')
       update_registry(started_at: DateTime.now)
 
-      if with_backup
-        log_info('Backup enabled')
-        actual_path = project.wiki.path_to_repo
-        backup_path = File.join(Dir.mktmpdir, 'wiki')
-
-        # Creating a backup copy and removing the main wiki
-        FileUtils.mv(actual_path, backup_path)
-      end
-
-      project.wiki.ensure_repository
-      fetch_geo_mirror(project.wiki.repository)
-
-      if with_backup
-        log_info('Removing backup copy as the repository was redownloaded successfully')
-        FileUtils.rm_r(backup_path)
+      if redownload
+        log_info('Redownloading wiki')
+        clean_up_temporary_repository
+        fetch_geo_mirror(build_temporary_repository)
+        set_temp_repository_as_main
+      else
+        project.wiki.ensure_repository
+        fetch_geo_mirror(project.wiki.repository)
       end
 
       update_registry(finished_at: DateTime.now)
@@ -42,15 +37,14 @@ module Geo
     rescue Gitlab::Git::Repository::NoRepository => e
       log_error('Invalid wiki', e)
       registry.update(force_to_redownload_wiki: true)
-    ensure
-      # Backup can only exist if redownload was unsuccessful
-      if with_backup && File.exist?(backup_path)
-        FileUtils.mv(backup_path, actual_path)
-      end
     end
 
     def ssh_url_to_wiki
       "#{primary_ssh_path_prefix}#{project.full_path}.wiki.git"
     end
+
+    def repository
+      project.wiki.repository
+    end
   end
 end