Port-forwarding for ProtonVPN

[muggajoe]

Type of change

• [ ] Bugfix (non-breaking change which fixes an issue)
• [ ] New provider (thank you!)
• [*] Updated provider (thank you!)
• [*] New feature (which adds functionality to a provider script/repo usage)
• [ ] Breaking change (fix/feature causing existing functionality to break)

Additional information

This change depends on natapmpc being installed in the transmission-openvpn container. natpmpc installation has been merged into the dev branch for haugene/docker-transmission-openvpn on 2023-11-14 - https://github.com/haugene/docker-transmission-openvpn/pull/2746

The script will fail gracefully if used with a build of haugene/docker-transmission-openvpn that does not have natpmpc installed.

Confirmed to work with the following ProtonVPN configs:

ch.protonvpn.net.udp es.protonvpn.net.tcp es.protonvpn.net.udp is.protonvpn.net.tcp is.protonvpn.net.udp ng.protonvpn.net.tcp ng.protonvpn.net.udp nl.protonvpn.net.tcp nl.protonvpn.net.udp ro.protonvpn.net.udp ro.protonvpn.net.tcp se.protonvpn.net.tcp se.protonvpn.net.udp uk.protonvpn.net.udp us.protonvpn.net.udp

Checklist

• [*] The code change is tested and works locally.
• [*] There is no commented out code in this PR.

If user exposed functionality or configuration variables are added/changed:

• [*] Documentation added/updated
  • see README.md in /openvpn/protonvpn/

[pkishino]

Nice, thanks

[ahti]

Fyi to make this work when using TRANSMISSION_RPC_AUTHENTICATION_REQUIRED=true, I had to modify update-port.sh by inserting the following block after the line with TRANSMISSION_PASSWD_FILE=... (found here, except I didn't need to hardcode my unhashed pw, as the one in transmission-credentials.txt wasn't hashed):

transmission_username=$(head -1 ${TRANSMISSION_PASSWD_FILE})
transmission_passwd=$(tail -1 ${TRANSMISSION_PASSWD_FILE})
transmission_settings_file=${TRANSMISSION_HOME}/settings.json

Without those, $transmission_settings_file wasn't set, so the script would always assume auth wasn't required.

[muggajoe]

The ProtonVPN update-port.sh has been updated with that change. Thanks!