This fixes a performance problem where we were previously starting up
a full Django process (~0.7s even on a fast machine) every time a new
email came in, potentially allowing users to accidentally DoS a Zulip
server. Now, we just post over HTTPS, allowing the existing thread
pool support to do its job.
- Add script wrapper to communicate postfix pipe with django web server
over HTTP(S). It uses shared_secret authentication mode.
- Add django view to process messages from email mirror server.
- Clean management command `email-mirror`. Left just functional
for cron email processing.
- Add routes for new tornado view.
- Change pipe script in master process postfix config template
based on updated script.
- Add tests.
Tweaked by tabbott to adjust the directory and set better defaults.
Fixes#2421.
Tim Abbott
K.Kanakhin