Merge remote-tracking branch 'upstream/master' into 27377-preload-pipeline-entity27377-preload-pipeline-entity

* upstream/master: (2534 commits)
  Update VERSION to 9.3.0-pre
  Update CHANGELOG.md for 9.2.0
  removes unnecessary redundacy in usage ping doc
  Respect the typo as rubocop said
  Add a test to ensure this works on MySQL
  Change pipelines schedules help page path
  change domain to hostname in usage ping doc
  Fixes broken MySQL migration for retried
  Show password field mask while editing service settings
  Add notes for supported schedulers and cloud providers
  Move environment monitoring to environments doc
  Add docs for change of Cache/Artifact restore order"
  Avoid resource intensive login checks if password is not provided
  Change translation for 'coding' by 'desarrollo' for Spanish
  Add to docs: issues multiple assignees
  rename "Add emoji" and "Award emoji" to "Add reaction" where appropriate
  Add project and group notification settings info
  32570 Fix border-bottom for project activity tab
  Add users endpoint to frontend API class
  Rename users on mysql
  ...

1 files changed, 22 insertions, 18 deletions

diff --git a/lib/gitlab/etag_caching/middleware.rb b/lib/gitlab/etag_caching/middleware.rb
index ffbc6e17dc5..270d67dd50c 100644
--- a/lib/gitlab/etag_caching/middleware.rb
+++ b/lib/gitlab/etag_caching/middleware.rb
@@ -1,27 +1,23 @@
 module Gitlab
   module EtagCaching
     class Middleware
-      RESERVED_WORDS = ProjectPathValidator::RESERVED.map { |word| "/#{word}/" }.join('|')
-      ROUTE_REGEXP = Regexp.union(
-        %r(^(?!.*(#{RESERVED_WORDS})).*/noteable/issue/\d+/notes\z)
-      )
-
       def initialize(app)
         @app = app
       end
 
       def call(env)
-        return @app.call(env) unless enabled_for_current_route?(env)
-        Gitlab::Metrics.add_event(:etag_caching_middleware_used)
+        route = Gitlab::EtagCaching::Router.match(env)
+        return @app.call(env) unless route
+
+        track_event(:etag_caching_middleware_used, route)
 
         etag, cached_value_present = get_etag(env)
         if_none_match = env['HTTP_IF_NONE_MATCH']
 
         if if_none_match == etag
-          Gitlab::Metrics.add_event(:etag_caching_cache_hit)
-          [304, { 'ETag' => etag }, ['']]
+          handle_cache_hit(etag, route)
         else
-          track_cache_miss(if_none_match, cached_value_present)
+          track_cache_miss(if_none_match, cached_value_present, route)
 
           status, headers, body = @app.call(env)
           headers['ETag'] = etag
@@ -31,10 +27,6 @@ module Gitlab
 
       private
 
-      def enabled_for_current_route?(env)
-        ROUTE_REGEXP.match(env['PATH_INFO'])
-      end
-
       def get_etag(env)
         cache_key = env['PATH_INFO']
         store = Gitlab::EtagCaching::Store.new
@@ -52,15 +44,27 @@ module Gitlab
         %Q{W/"#{value}"}
       end
 
-      def track_cache_miss(if_none_match, cached_value_present)
+      def handle_cache_hit(etag, route)
+        track_event(:etag_caching_cache_hit, route)
+
+        status_code = Gitlab::PollingInterval.polling_enabled? ? 304 : 429
+
+        [status_code, { 'ETag' => etag }, []]
+      end
+
+      def track_cache_miss(if_none_match, cached_value_present, route)
         if if_none_match.blank?
-          Gitlab::Metrics.add_event(:etag_caching_header_missing)
+          track_event(:etag_caching_header_missing, route)
         elsif !cached_value_present
-          Gitlab::Metrics.add_event(:etag_caching_key_not_found)
+          track_event(:etag_caching_key_not_found, route)
         else
-          Gitlab::Metrics.add_event(:etag_caching_resource_changed)
+          track_event(:etag_caching_resource_changed, route)
         end
       end
+
+      def track_event(name, route)
+        Gitlab::Metrics.add_event(name, endpoint: route.name)
+      end
     end
   end
 end