I have a use case where a webpage and read only file listing is available on port 80 for the resin-vpn interface which is provided on the balena public url on 443/80.
I uses HSTS to ensure HTTPS connection on the balena url which has been advised for in Public url via http to ensure ‘secure’ connection eventhough RFC6797( https://www.rfc-editor.org/rfc/rfc6797.txt ) guides against HSTS in HTTP, see section 7.2.
The webpage and file listing is working as expected.
Additionally I try to provide WebDAV via the balena public url. I can use the unsecure port 80 for webdav access. If I try to connect to the Webdav on port 443, then the initial handshakes are performed on port 443 and then downgraded to port 80 for all remaining data transfers. This is no good.
In this case apache should redirect port 80 to port 443, but 443 is not accessible from the public url.