There are several places in the code where comma-ok map retrieval was
being used poorly. Some were benign, like checking existence before
issuing an unconditional delete with no cleanup. Others were potentially
far more serious: assuming that if 'ok' was true, then the resulting
pointer retrieved from the map would be non-nil. `nil` is a perfectly
valid value to store in a map of pointers, and the comma-ok syntax is
meant for when membership is distinct from having a non-zero value.
There was only one or two cases that I saw that being used correctly for
maps of pointers.
After using `/debug/requests`, the client will wait for 30 seconds
(configurable by specifying `seconds=` in the query parameters) and the
HTTP handler will track every incoming query and write to the system.
After that time period has passed, it will output a JSON blob that looks
very similar to `/debug/vars` that shows every IP address and user
account (if authentication is used) that connected to the host during
that time.
In the future, we can add more metrics to track. This is an initial
start to aid with debugging machines that connect too often by looking
at a sample of time (like `/debug/pprof`).
Joe LeGasse
Jonathan A. Sternberg