Fix api_json.log not always reporting the right HTTP status code

As described in https://github.com/aserafin/grape_logging/issues/45, if
a Grape error is caught by the handlers and a different return code
is returned, then the api_json.log would have a 500 error code
instead of the right value. Inserting the GrapeLogging middleware
after the Grape middleware fixes this problem.

Seen in https://gitlab.com/gitlab-com/infrastructure/issues/4249

changelogs/unreleased/sh-fix-grape-logging-status-code.yml

+---
+title: Fix api_json.log not always reporting the right HTTP status code
+merge_request:
+author:
+type: fixed

lib/api/api.rb

@@ -8,14 +8,15 @@ module API
     PROJECT_ENDPOINT_REQUIREMENTS = { id: NO_SLASH_URL_PART_REGEX }.freeze
     COMMIT_ENDPOINT_REQUIREMENTS = PROJECT_ENDPOINT_REQUIREMENTS.merge(sha: NO_SLASH_URL_PART_REGEX).freeze
 
-    use GrapeLogging::Middleware::RequestLogger,
-        logger: Logger.new(LOG_FILENAME),
-        formatter: Gitlab::GrapeLogging::Formatters::LogrageWithTimestamp.new,
-        include: [
-          GrapeLogging::Loggers::FilterParameters.new,
-          GrapeLogging::Loggers::ClientEnv.new,
-          Gitlab::GrapeLogging::Loggers::UserLogger.new
-        ]
+    insert_before Grape::Middleware::Error,
+                  GrapeLogging::Middleware::RequestLogger,
+                  logger: Logger.new(LOG_FILENAME),
+                  formatter: Gitlab::GrapeLogging::Formatters::LogrageWithTimestamp.new,
+                  include: [
+                    GrapeLogging::Loggers::FilterParameters.new,
+                    GrapeLogging::Loggers::ClientEnv.new,
+                    Gitlab::GrapeLogging::Loggers::UserLogger.new
+                  ]
 
     allow_access_with_scope :api
     prefix :api