Merge branch 'feature/gb/internal-pages-domain-no-content' into 'master'

Respond with 204 no content when pages domain does not exist

See merge request gitlab-org/gitlab!21059

lib/api/internal/pages.rb

@@ -25,7 +25,7 @@ module API
           end
           get "/" do
             host = Namespace.find_by_pages_host(params[:host]) || PagesDomain.find_by_domain(params[:host])
-            not_found! unless host
+            no_content! unless host
 
             virtual_domain = host.pages_virtual_domain
             no_content! unless virtual_domain

spec/requests/api/internal/pages_spec.rb

@@ -47,11 +47,12 @@ describe API::Internal::Pages do
           project.mark_pages_as_deployed
         end
 
-        context 'not existing host' do
-          it 'responds with 404 Not Found' do
+        context 'domain does not exist' do
+          it 'responds with 204 no content' do
             query_host('pages.gitlab.io')
 
-            expect(response).to have_gitlab_http_status(404)
+            expect(response).to have_gitlab_http_status(204)
+            expect(response.body).to be_empty
           end
         end