Add deprecation guard to prevent further usage of NamespaceService

Namespace service is in process of being deprecated since it is not
compatible with Gitaly HA. Hence, we want to prevent future usage of it
by forcing callers to wrap Namespace Service calls in an allow block

app/models/concerns/storage/legacy_namespace.rb

@@ -57,6 +57,7 @@ module Storage
       # Move the namespace directory in all storages used by member projects
       repository_storages(legacy_only: true).each do |repository_storage|
         # Ensure old directory exists before moving it
+        Gitlab::GitalyClient::NamespaceService.allow do
           gitlab_shell.add_namespace(repository_storage, full_path_before_last_save)
 
           # Ensure new directory exists before moving it (if there's a parent)
@@ -72,6 +73,7 @@ module Storage
           end
         end
       end
+    end
 
     def old_repository_storages
       @old_repository_storage_paths ||= repository_storages
@@ -95,6 +97,7 @@ module Storage
         # We will remove it later async
         new_path = "#{full_path}+#{id}+deleted"
 
+        Gitlab::GitalyClient::NamespaceService.allow do
           if gitlab_shell.mv_namespace(repository_storage, full_path, new_path)
             Gitlab::AppLogger.info %Q(Namespace directory "#{full_path}" moved to "#{new_path}")
 
@@ -107,4 +110,5 @@ module Storage
         end
       end
     end
+  end
 end

app/workers/gitlab_shell_worker.rb

@@ -8,6 +8,8 @@ class GitlabShellWorker
   latency_sensitive_worker!
 
   def perform(action, *arg)
+    Gitlab::GitalyClient::NamespaceService.allow do
       gitlab_shell.__send__(action, *arg) # rubocop:disable GitlabSecurity/PublicSend
     end
+  end
 end

lib/gitlab/database/rename_reserved_paths_migration/v1/rename_namespaces.rb

@@ -66,6 +66,7 @@ module Gitlab
           def move_repositories(namespace, old_full_path, new_full_path)
             repo_shards_for_namespace(namespace).each do |repository_storage|
               # Ensure old directory exists before moving it
+              Gitlab::GitalyClient::NamespaceService.allow do
                 gitlab_shell.add_namespace(repository_storage, old_full_path)
 
                 unless gitlab_shell.mv_namespace(repository_storage, old_full_path, new_full_path)
@@ -74,6 +75,7 @@ module Gitlab
                 end
               end
             end
+          end
 
           def repo_shards_for_namespace(namespace)
             projects_for_namespace(namespace).distinct.select(:repository_storage)

lib/gitlab/gitaly_client/namespace_service.rb

@@ -3,7 +3,22 @@
 module Gitlab
   module GitalyClient
     class NamespaceService
+      extend Gitlab::TemporarilyAllow
+
+      NamespaceServiceAccessError = Class.new(StandardError)
+      ALLOW_KEY = :allow_namespace
+
+      def self.allow
+        temporarily_allow(ALLOW_KEY) { yield }
+      end
+
+      def self.denied?
+        !temporarily_allowed?(ALLOW_KEY)
+      end
+
       def initialize(storage)
+        raise NamespaceServiceAccessError if self.class.denied?
+
         @storage = storage
       end
 

spec/lib/gitlab/shell_spec.rb

@@ -401,7 +401,7 @@ describe Gitlab::Shell do
 
     describe '#add_namespace' do
       it 'creates a namespace' do
-        subject.add_namespace(storage, "mepmep")
+        Gitlab::GitalyClient::NamespaceService.allow { subject.add_namespace(storage, "mepmep") }
 
         expect(TestEnv.storage_dir_exists?(storage, "mepmep")).to be(true)
       end
@@ -425,8 +425,10 @@ describe Gitlab::Shell do
 
     describe '#remove' do
       it 'removes the namespace' do
+        Gitlab::GitalyClient::NamespaceService.allow do
           subject.add_namespace(storage, "mepmep")
           subject.rm_namespace(storage, "mepmep")
+        end
 
         expect(TestEnv.storage_dir_exists?(storage, "mepmep")).to be(false)
       end
@@ -434,8 +436,10 @@ describe Gitlab::Shell do
 
     describe '#mv_namespace' do
       it 'renames the namespace' do
+        Gitlab::GitalyClient::NamespaceService.allow do
           subject.add_namespace(storage, "mepmep")
           subject.mv_namespace(storage, "mepmep", "2mep")
+        end
 
         expect(TestEnv.storage_dir_exists?(storage, "mepmep")).to be(false)
         expect(TestEnv.storage_dir_exists?(storage, "2mep")).to be(true)