Enable caching of git blobs even when signed in

We should skip the `no-store` cache control header that we append by
default in these controller actions where we want to cache. We already
do this for some controllers like uploads but this was missing for a
very long time now.

app/controllers/projects/avatars_controller.rb

@@ -3,6 +3,8 @@
 class Projects::AvatarsController < Projects::ApplicationController
   include SendsBlob
 
+  skip_before_action :default_cache_headers, only: :show
+
   before_action :authorize_admin_project!, only: [:destroy]
 
   feature_category :projects

app/controllers/projects/raw_controller.rb

@@ -6,6 +6,8 @@ class Projects::RawController < Projects::ApplicationController
   include SendsBlob
   include StaticObjectExternalStorage
 
+  skip_before_action :default_cache_headers, only: :show
+
   prepend_before_action(only: [:show]) { authenticate_sessionless_user!(:blob) }
 
   before_action :require_non_empty_project

app/controllers/projects/repositories_controller.rb

@@ -8,6 +8,8 @@ class Projects::RepositoriesController < Projects::ApplicationController
 
   prepend_before_action(only: [:archive]) { authenticate_sessionless_user!(:archive) }
 
+  skip_before_action :default_cache_headers, only: :archive
+
   # Authorize
   before_action :require_non_empty_project, except: :create
   before_action :archive_rate_limit!, only: :archive

changelogs/unreleased/cache-raw-endpoints-for-logged-in-users.yml

+---
+title: Enable HTTP caching of repository raw, archive, and avatar endpoints
+merge_request: 47430
+author:
+type: performance

spec/controllers/projects/avatars_controller_spec.rb

@@ -3,14 +3,14 @@
 require 'spec_helper'
 
 RSpec.describe Projects::AvatarsController do
-  let_it_be(:project) { create(:project, :repository) }
+  describe 'GET #show' do
+    let_it_be(:project) { create(:project, :public, :repository) }
 
     before do
       controller.instance_variable_set(:@project, project)
     end
 
-  describe 'GET #show' do
-    subject { get :show, params: { namespace_id: project.namespace, project_id: project } }
+    subject { get :show, params: { namespace_id: project.namespace, project_id: project.path } }
 
     context 'when repository has no avatar' do
       it 'shows 404' do
@@ -37,6 +37,15 @@ RSpec.describe Projects::AvatarsController do
           expect(response.header[Gitlab::Workhorse::DETECT_HEADER]).to eq 'true'
         end
 
+        it 'sets appropriate caching headers' do
+          sign_in(project.owner)
+          subject
+
+          expect(response.cache_control[:public]).to eq(true)
+          expect(response.cache_control[:max_age]).to eq(60)
+          expect(response.cache_control[:no_store]).to be_nil
+        end
+
         it_behaves_like 'project cache control headers'
       end
 
@@ -51,9 +60,16 @@ RSpec.describe Projects::AvatarsController do
   end
 
   describe 'DELETE #destroy' do
+    let(:project) { create(:project, :repository, avatar: fixture_file_upload("spec/fixtures/dk.png", "image/png")) }
+
+    before do
+      sign_in(project.owner)
+    end
+
     it 'removes avatar from DB by calling destroy' do
-      delete :destroy, params: { namespace_id: project.namespace.id, project_id: project.id }
+      delete :destroy, params: { namespace_id: project.namespace.path, project_id: project.path }
 
+      expect(response).to redirect_to(edit_project_path(project, anchor: 'js-general-project-settings'))
       expect(project.avatar.present?).to be_falsey
       expect(project).to be_valid
     end

spec/controllers/projects/raw_controller_spec.rb

@@ -226,6 +226,15 @@ RSpec.describe Projects::RawController do
         get(:show, params: { namespace_id: project.namespace, project_id: project, id: 'master/README.md' })
       end
 
+      it 'sets appropriate caching headers' do
+        sign_in create(:user)
+        request_file
+
+        expect(response.cache_control[:public]).to eq(true)
+        expect(response.cache_control[:max_age]).to eq(60)
+        expect(response.cache_control[:no_store]).to be_nil
+      end
+
       context 'when If-None-Match header is set' do
         it 'returns a 304 status' do
           request_file

spec/controllers/projects/repositories_controller_spec.rb

@@ -122,7 +122,9 @@ RSpec.describe Projects::RepositoriesController do
 
           expect(response).to have_gitlab_http_status(:ok)
           expect(response.header['ETag']).to be_present
-          expect(response.header['Cache-Control']).to include('max-age=60, private')
+          expect(response.cache_control[:public]).to eq(false)
+          expect(response.cache_control[:max_age]).to eq(60)
+          expect(response.cache_control[:no_store]).to be_nil
         end
 
         context 'when project is public' do