Phusion Passenger Enterprise fails to connect to the licensing server behind a proxy - passenger

Question

We're trying to upgrade to Phusion Passenger Enterprise edition from the open source version but we're running into an issue. Passenger fails to connect to the licensing server with the following error message:
[ W 2018-03-27 10:20:55.2565 35498/T6 age/Cor/CloudUsageTracker.h:439 ]: Could not contact the Phusion Passenger Enterprise licensing server (HTTP error: Failed to connect to www.phusionpassenger.com port 443: Connection timed out). To ensure proper access to the licensing server, please try these:
- Ensure that your network connection to https://www.phusionpassenger.com works.
- If you can only access https://www.phusionpassenger.com via a proxy, please set the config option 'PassengerCtl licensing_proxy PROXY_URL' (Apache) or 'passenger_ctl licensing_proxy PROXY_URL' (Nginx). 'PROXY_URL' takes the format of protocol://username:password#hostname:port, where 'protocol' is either 'http' or 'socks5'.
We need to use a proxy for all outgoing HTTP connections, so I have added the recommended config option:
passenger_ctl licensing_proxy http://OURPROXY:3128;
However the issue persist with the same error message.
Using curl to hit this URL through the proxy works as expected:
$ curl -x http://OURPROXY:3128 https://www.phusionpassenger.com
We are using nginx with Passenger on Ubuntu 14.04 LTS, Passenger Enterprise is installed from the official APT repository.
What could be causing this error? Any help would be much appreciated.

Answer 1

I have received an answer to this question from the Phusion Passenger support. They had accidentally misspelled the name of the relevant config option in the error message.
The correct way to set this option is:
passenger_ctl licensing_proxy_url http://OURPROXY:3128;
Related to this question, if you want Passenger to check for security updates behind a proxy, you will also need to set that separately:
passenger_security_update_check_proxy http://OURPROXY:3128;