Is there anywhere that I can see a list of requests that pub/sub has made to a particular push endpoint? I don't need much info -- something like "this endpoint was called at this time" would be perfect.
I have searched through stackdriver logs but I can't find any log lines like this from pubsub.
I have tried stackdriver metrics but I can't really see the individual events. That API seems more suited to monitoring aggregate metrics but I'm trying to debug something where I really need to know "this endpoint was called at this time".
Pub/Sub does not log the individual requests made to push endpoints, no. As you discovered, you can find aggregate rate data such as push_request_count to determine if there were any requests during the time you are interested in, but you won't be able to determine which specific messages were sent during that time.