Add option to disable git archive caching in workhorse

GITLAB_WORKHORSE_VERSION

-3.4.0
+3.5.0

lib/gitlab/workhorse.rb

@@ -97,6 +97,9 @@ module Gitlab
           )
         end
 
+        # If present DisableCache must be a Boolean. Otherwise workhorse ignores it.
+        params['DisableCache'] = true if git_archive_cache_disabled?
+
         [
           SEND_DATA_HEADER,
           "git-archive:#{encode(params)}"
@@ -244,6 +247,10 @@ module Gitlab
           right_commit_id: diff_refs.head_sha
         }
       end
+
+      def git_archive_cache_disabled?
+        ENV['WORKHORSE_ARCHIVE_CACHE_DISABLED'].present? || Feature.enabled?(:workhorse_archive_cache_disabled)
+      end
     end
   end
 end

spec/lib/gitlab/workhorse_spec.rb

@@ -26,11 +26,16 @@ describe Gitlab::Workhorse do
         'GitalyRepository' => repository.gitaly_repository.to_h.deep_stringify_keys
       )
     end
+    let(:cache_disabled) { false }
 
     subject do
       described_class.send_git_archive(repository, ref: ref, format: format)
     end
 
+    before do
+      allow(described_class).to receive(:git_archive_cache_disabled?).and_return(cache_disabled)
+    end
+
     context 'when Gitaly workhorse_archive feature is enabled' do
       it 'sets the header correctly' do
         key, command, params = decode_workhorse_header(subject)
@@ -39,6 +44,15 @@ describe Gitlab::Workhorse do
         expect(command).to eq('git-archive')
         expect(params).to include(gitaly_params)
       end
+
+      context 'when archive caching is disabled' do
+        let(:cache_disabled) { true }
+
+        it 'tells workhorse not to use the cache' do
+          _, _, params = decode_workhorse_header(subject)
+          expect(params).to include({ 'DisableCache' => true })
+        end
+      end
     end
 
     context 'when Gitaly workhorse_archive feature is disabled', :skip_gitaly_mock do