I built a webapplication (php/java) for a museum in the Netherlands. The webaplication runs on an ArchArm Raspberry 3. I installed a local webserver (lighttpd) to avoid dependency of the application on an internetconnection.
The Raspberry is able to talk to the internet, but I can't (ssh) reach the device remotely, because ports on the router cannot be changed.
The challenge for me is now to remotely update the webapplication's source code, without direct access to the source code.
I was thinking to use a cron script on the device, that would invoke 'rsync' to check if there were file differences, and if 'Yes' update them on the Raspberry.
My question is: Which workaround/method would you chose in this situation?