Handle tag delete 404

When deleting registry tags using dummy images,
the intermediate dummy might be deleted by another
thread and get a 404 when trying to delete it.
The tags go aways regardless so take it as a success

app/models/container_repository.rb

@@ -67,7 +67,7 @@ class ContainerRepository < ApplicationRecord
   def delete_tags!
     return unless has_tags?
 
-    digests = tags.map { |tag| tag.digest }.to_set
+    digests = tags.map { |tag| tag.digest }.compact.to_set
 
     digests.all? do |digest|
       delete_tag_by_digest(digest)

app/services/projects/container_repository/delete_tags_service.rb

@@ -48,10 +48,10 @@ module Projects
         # rubocop: disable CodeReuse/ActiveRecord
         Gitlab::Sentry.track_exception(ArgumentError.new('multiple tag digests')) if tag_digests.many?
 
-        # deletes the dummy image
-        # all created tag digests are the same since they all have the same dummy image.
+        # Deletes the dummy image
+        # All created tag digests are the same since they all have the same dummy image.
         # a single delete is sufficient to remove all tags with it
-        if container_repository.client.delete_repository_tag(container_repository.path, tag_digests.first)
+        if container_repository.delete_tag_by_digest(tag_digests.first)
           success(deleted: tag_names)
         else
           error('could not delete tags')

lib/container_registry/client.rb

@@ -36,7 +36,9 @@ module ContainerRegistry
     end
 
     def delete_repository_tag(name, reference)
-      faraday.delete("/v2/#{name}/manifests/#{reference}").success?
+      result = faraday.delete("/v2/#{name}/manifests/#{reference}")
+
+      result.success? || result.status == 404
     end
 
     def upload_raw_blob(path, blob)
@@ -84,7 +86,9 @@ module ContainerRegistry
     end
 
     def delete_blob(name, digest)
-      faraday.delete("/v2/#{name}/blobs/#{digest}").success?
+      result = faraday.delete("/v2/#{name}/blobs/#{digest}")
+
+      result.success? || result.status == 404
     end
 
     def put_tag(name, reference, manifest)

spec/services/projects/container_repository/cleanup_tags_service_spec.rb

@@ -157,6 +157,6 @@ describe Projects::ContainerRepository::CleanupTagsService do
   def expect_delete(digest)
     expect_any_instance_of(ContainerRegistry::Client)
       .to receive(:delete_repository_tag)
-      .with(repository.path, digest)
+      .with(repository.path, digest) { true }
   end
 end

spec/services/projects/container_repository/delete_tags_service_spec.rb

@@ -87,6 +87,21 @@ describe Projects::ContainerRepository::DeleteTagsService do
 
           is_expected.to include(status: :success)
         end
+
+        it 'succedes when tag delete returns 404' do
+          stub_upload("{\n  \"config\": {\n  }\n}", 'sha256:4435000728ee66e6a80e55637fc22725c256b61de344a2ecdeaac6bdb36e8bc3')
+
+          stub_request(:put, "http://registry.gitlab/v2/#{repository.path}/manifests/A")
+            .to_return(status: 200, body: "", headers: { 'docker-content-digest' => 'sha256:dummy' })
+
+          stub_request(:put, "http://registry.gitlab/v2/#{repository.path}/manifests/Ba")
+            .to_return(status: 200, body: "", headers: { 'docker-content-digest' => 'sha256:dummy' })
+
+          stub_request(:delete, "http://registry.gitlab/v2/#{repository.path}/manifests/sha256:dummy")
+            .to_return(status: 404, body: "", headers: {})
+
+          is_expected.to include(status: :success)
+        end
       end
     end
   end