Add JSON logger in `log/api_json.log` for Grape API endpoints

Closes #36189

2 files changed, 17 insertions, 0 deletions

diff --git a/lib/api/api.rb b/lib/api/api.rb
index 1405a5d0f0e..63df22c508b 100644
--- a/lib/api/api.rb
+++ b/lib/api/api.rb
@@ -2,6 +2,15 @@ module API
   class API < Grape::API
     include APIGuard
 
+    LOG_FILENAME = Rails.root.join("log", "api_json.log")
+
+    use GrapeLogging::Middleware::RequestLogger,
+        logger: ::Gitlab::ApiLogger.new(LOG_FILENAME),
+        formatter: GrapeLogging::Formatters::Json.new,
+        include: [ GrapeLogging::Loggers::Response.new,
+                   GrapeLogging::Loggers::FilterParameters.new,
+                   GrapeLogging::Loggers::ClientEnv.new ]
+
     allow_access_with_scope :api
     prefix :api
 
diff --git a/lib/gitlab/api_logger.rb b/lib/gitlab/api_logger.rb
new file mode 100644
index 00000000000..09122b233ea
--- /dev/null
+++ b/lib/gitlab/api_logger.rb
@@ -0,0 +1,8 @@
+module Gitlab
+  class ApiLogger < ::Logger
+
+    def format_message(severity, timestamp, progname, message)
+      super + "\n"
+    end
+  end
+end