Create staging weblate repository and update hook.

Create a weblate staging repository by cloning from the weblate main
repository. A git post update hook is added to the main repository so
the staging repository always merges changes made to the main
repository.

Part of #12311.

manifests/weblate.pp

@@ -134,6 +134,35 @@ class tails::weblate (
     user     => root,
   }
 
+  # Staging repository
+
+  #file { "${mutable_data_dir}/repositories/vcs/tails/index":
+  #  ensure => directory,
+  #  owner  => weblate,
+  #  group  => weblate,
+  #  mode   => '2770',
+  #}
+
+  vcsrepo { "${mutable_data_dir}/staging":
+    # TODO: the creation of this repository depends on the existence of the
+    # main weblate git repository, which is currently not managed by puppet.
+    provider => git,
+    source   => "${mutable_data_dir}/repositories/vcs/tails/index",
+    revision => $code_git_revision,
+    user     => weblate,
+    #require => File["$mutable_data_dir/repositories/vcs/tails/index"],
+  }
+
+  file { "${mutable_data_dir}/repositories/vcs/tails/index/.git/hooks/post-update"
+    owner   => weblate,
+    group   => weblate_admin,
+    mode    => '0770',
+    content  => template('weblate/hooks/main/post-update.sh.erb'),
+    require => Vcsrepo["$${mutable_data_dir}/staging"],
+    # TODO: this should also require existence of the .git/hooks directory,
+    # which is currently not managed by puppet.
+  }
+
   # Service
 
   service { 'apache2':

templates/weblate/hooks/main/post-update.sh.erb

+#!/bin/sh
+
+STAGING_PATH=<%= mutable_data_dir %>/staging
+
+# import all changes from main weblate repo into staging repo
+git -C ${STAGING_PATH} merge -S recursive -X theirs origin master