Don't instrument 405 Grape calls

Fixes #26051.

Signed-off-by: Rémy Coutable <remy@rymai.me>

1 files changed, 6 insertions, 2 deletions

diff --git a/lib/gitlab/metrics/rack_middleware.rb b/lib/gitlab/metrics/rack_middleware.rb
index 91fb0bb317a..d01d47a6a7a 100644
--- a/lib/gitlab/metrics/rack_middleware.rb
+++ b/lib/gitlab/metrics/rack_middleware.rb
@@ -70,8 +70,12 @@ module Gitlab
 
       def tag_endpoint(trans, env)
         endpoint = env[ENDPOINT_KEY]
-        path = endpoint_paths_cache[endpoint.route.request_method][endpoint.route.path]
-        trans.action = "Grape##{endpoint.route.request_method} #{path}"
+
+        # endpoint.route is nil in the case of a 405 response
+        if endpoint.route
+          path = endpoint_paths_cache[endpoint.route.request_method][endpoint.route.path]
+          trans.action = "Grape##{endpoint.route.request_method} #{path}"
+        end
       end
 
       private