I'm also unable to use "localhost" in Sonarr/Radarr/etc. Setting them to the app IP of 172.17.x.x works. I'm also still having DNS leaks with a Firefox proxy pointing at DelugeVPN as detailed here. Everything, including DelugeVPN, is set to Network type = Bridge in the container settings. Sonarr, Radarr, NZBHydra2, Jackett, etc., are all using HTTP proxy with 172.17.x.x:8118 and "bypass local network" turned on. This may be the wrong way to use DelugeVPN with other containers, I'm not sure.
I'm also now getting this in my log over and over, even though everything seems to be working if you ignore the DNS leak.
2021-02-25 17:25:10,431 DEBG 'watchdog-script' stdout output:
[info] Starting Deluge Web UI...
2021-02-25 17:25:10,432 DEBG 'watchdog-script' stdout output:
[info] Deluge Web UI started
2021-02-25 17:25:10,433 DEBG 'watchdog-script' stdout output:
[info] Attempting to start Privoxy...
2021-02-25 17:25:11,444 DEBG 'watchdog-script' stdout output:
[info] Privoxy process started
[info] Waiting for Privoxy process to start listening on port 8118...
2021-02-25 17:25:11,449 DEBG 'watchdog-script' stdout output:
[info] Privoxy process listening on port 8118
2021-02-25 17:25:11,449 DEBG 'watchdog-script' stdout output:
[debug] VPN IP is XXXXXX
[debug] Deluge IP is XXXXXX
2021-02-25 17:25:41,451 DEBG 'watchdog-script' stdout output:
[debug] Checking we can resolve name 'www.google.com' to address...
2021-02-25 17:25:41,481 DEBG 'watchdog-script' stdout output:
[debug] DNS operational, we can resolve name 'www.google.com' to address '172.217.1.4'
2021-02-25 17:25:41,482 DEBG 'watchdog-script' stdout output:
[debug] Waiting for iptables chain policies to be in place...
2021-02-25 17:25:41,490 DEBG 'watchdog-script' stdout output:
[debug] iptables chain policies are in place
2021-02-25 17:25:41,502 DEBG 'watchdog-script' stdout output:
[info] Privoxy not running
2021-02-25 17:25:41,503 DEBG 'watchdog-script' stdout output:
[info] Attempting to start Privoxy...
<repeat forever>