In our application, we have an Ignition gateway setup behind an nginx reverse proxy that, for all Ignition purposes, seems to work just fine. However, we have an intermittent issue related to the Web Dev module it seems.
I have a Web Dev route set up to handle POST requests. It is a script and simply takes JSON data that gets sent with the POST request and inserts it into a database. There are multiple devices that send to this endpoint on a regular basis, and occasionally (and seemingly randomly) the request will fail. The device sees an HTTP 502 error from its end, and I notice that in the nginx error logs I see:
SSL_write() failed (10053: An established connection was aborted by the software in your host machine) while sending request to upstream
I have a logging statement in the script for the endpoint that logs whenever the script starts running, and when this error occurs, the logging never happens, indicating that the script is never being entered at all and the failure happens before the script handles the request.
I am able to find very little information about this error online, and restarting the gateway/the entire gateway server don't seem to make the issue go away or become less frequent.
Here's a pastebin of the nginx.conf
I'm using (with the real domain of our application replaced with example.com, but everything else is the same) Ubuntu Pastebin