automatically purge logs

[lanterndev]

Currently there is no way to configure an App Engine application to not log any requests. The log retention UI under Application Settings looks like:

Logs Retention
Google App Engine will store logs up to X days in the past, where X is specified below, or up to the storage limit size set below, whichever limit is reached first.
___ GBytes of logs storage or ___ days of logs. (Maximum number of days: 365)

and the minimum values it accepts appear to be 1 and 0 respectively.

Barring a way to configure zero log retention, we should somehow automate frequent purging of logs.