I have set $conf['reverse_proxy'] = TRUE;
in settings.php, but the IP address logged in the flood table is 127.0.0.1, not the one passed through the X-Forwarded-For header. Nginx is configured to send the X-Forwarded-For header to Apache, but it seems Drupal isn't recognizing it.
This is pretty bad because a few failed logins can lockout for everyone.
How can I make Drupal use the IP passed within the X-Forwarded-For header?