Introduce ci_live_trace_use_fog_attributes feature flag

This commit reverts some of the previous commit to be more amenable for
adding a feature feature flag to avoid introducing a bug in the CI live
trace functionality.

app/models/ci/build_trace_chunks/fog.rb

@@ -4,7 +4,7 @@ module Ci
   module BuildTraceChunks
     class Fog
       def available?
-        object_store_config.enabled?
+        object_store.enabled
       end
 
       def data(model)
@@ -14,7 +14,15 @@ module Ci
       end
 
       def set_data(model, new_data)
-        files.create(create_attributes(model, new_data))
+        if Feature.enabled?(:ci_live_trace_use_fog_attributes)
+          files.create(create_attributes(model, new_data))
+        else
+          # TODO: Support AWS S3 server side encryption
+          files.create({
+            key: key(model),
+            body: new_data
+          })
+        end
       end
 
       def append_data(model, new_data, offset)
@@ -67,13 +75,13 @@ module Ci
       def bucket_name
         return unless available?
 
-        object_store_config.bucket
+        object_store.remote_directory
       end
 
       def connection
         return unless available?
 
-        @connection ||= ::Fog::Storage.new(object_store_config.credentials)
+        @connection ||= ::Fog::Storage.new(object_store.connection.to_hash.deep_symbolize_keys)
       end
 
       def fog_directory
@@ -84,10 +92,14 @@ module Ci
         @files ||= fog_directory.files
       end
 
-      def object_store_raw_config
+      def object_store
         Gitlab.config.artifacts.object_store
       end
 
+      def object_store_raw_config
+        object_store
+      end
+
       def object_store_config
         @object_store_config ||= ::ObjectStorage::Config.new(object_store_raw_config)
       end

config/feature_flags/development/ci_live_trace_use_fog_attributes.yml

+---
+name: ci_live_trace_use_fog_attributes
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/47536
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/285079
+milestone: '13.6'
+type: development
+group: group::testing
+default_enabled: false

spec/models/ci/build_trace_chunks/fog_spec.rb

@@ -98,6 +98,27 @@ RSpec.describe Ci::BuildTraceChunks::Fog do
 
           expect(data_store.data(model)).to eq new_data
         end
+
+        context 'when ci_live_trace_use_fog_attributes flag is disabled' do
+          before do
+            stub_feature_flags(ci_live_trace_use_fog_attributes: false)
+          end
+
+          it 'does not pass along Fog attributes' do
+            expect_next_instance_of(Fog::AWS::Storage::Files) do |files|
+              expect(files).to receive(:create).with(
+                key: anything,
+                body: new_data
+              ).and_call_original
+            end
+
+            expect(data_store.data(model)).to be_nil
+
+            data_store.set_data(model, new_data)
+
+            expect(data_store.data(model)).to eq new_data
+          end
+        end
       end
     end
   end