Add gc debugging flag to help debug prod thumbnails leak (#3354)

* Add gc debugging flag to help debug prod thumbnails leak

* Add documentation to the new environment variable

* Simplify setting aggregation

api/conf/asgi.py

@@ -20,3 +20,13 @@ def get_asgi_application():
 
 if settings.ENVIRONMENT == "local":
     static_files_application = ASGIStaticFilesHandler(application)
+
+
+if settings.GC_DEBUG_LOGGING:
+    import gc
+
+    setting = 0
+    for flag in settings.GC_DEBUG_LOGGING:
+        setting |= getattr(gc, flag)
+
+    gc.set_debug(setting)

api/conf/settings/logging.py

@@ -14,6 +14,12 @@ def health_check_filter(record: LogRecord) -> bool:
 LOG_LEVEL = config("LOG_LEVEL", default="INFO").upper()
 DJANGO_DB_LOGGING = config("DJANGO_DB_LOGGING", cast=bool, default=False)
 
+# Set to a pipe-delimited string of gc debugging flags
+# https://docs.python.org/3/library/gc.html#gc.DEBUG_STATS
+GC_DEBUG_LOGGING = config(
+    "GC_DEBUG_LOGGING", cast=lambda x: x.split("|") if x else [], default=""
+)
+
 # https://github.com/dabapps/django-log-request-id#logging-all-requests
 LOG_REQUESTS = True