Automatically Update Deluge Listen Port When Gluetun Vpn Updates
This post details how to create a systemd service that automatically updates Deluge’s Listen Port when the forwarded port changes on a gluetun vpn connection container.
Background
I have two relevant docker instances
- Deluge
- Gluetun connection using proton vpn, connected via openvpn credentials
Deluge uses the vpn container as its network.
When the VPN connection periodically changes to a new address, the forwarded port also changes.
Gluetun helpfully exposes the port via the file /home/MY_HOME/protonvpn/tmp/forwarded_port
We can watch this file for changes and use deluge console to update the Incoming Port setting.
Deluge Docker compose file
services:
deluge:
image: lscr.io/linuxserver/deluge:latest
container_name: deluge
environment:
- PUID=1000
- PGID=1000
- TZ=Etc/UTC
- DELUGE_LOGLEVEL=error #optional
volumes:
- /home/MY_HOME/deluge/config:/config
- /MY_TORRENTS:/torrents
network_mode: "container:gluetun"
restart: unless-stopped
# Port forwarding is configured in protonvpn / gluetun container
Gluetun docker compose file
version: "3"
services:
gluetun:
image: qmcgaw/gluetun
container_name: gluetun
cap_add:
- NET_ADMIN
devices:
- /dev/net/tun:/dev/net/tun
environment:
- VPN_SERVICE_PROVIDER=protonvpn
- VPN_PORT_FORWARDING=on
- PORT_FORWARD_ONLY=on
- VPN_PORT_FORWARDING_UP_COMMAND=/bin/sh -c "echo "
- OPENVPN_USER=MY_OPENVPN_USER
- OPENVPN_PASSWORD=MY_OPENVPN_PASSWORD
ports:
- 8112:8112 # Deluge web ui
- 58846:58846 # Deluge daemon
# Other ports for other containers here that you want to use this connection. e.g. cardigann, jackett
volumes:
- /home/MY_USER/protonvpn/tmp:/tmp/gluetun
restart: unless-stopped
Test changing deluge setting
docker exec -i deluge deluge-console -c /config "config --set listen_ports (50000, 50000)"
Problems encountered with the deluge console command
Config directory not set, permissions error
The -c /config directory setting must match the deluge docker config volume mapping. Otherwise there is a permissions error.
Could not connect to daemon: 127.0.0.1:58846
Password does not match
Opening the interactive deluge-console command lists only a localclient connection, not the full list of connections I have configured.
Listen_ports incorrect format, set to first character of port specified
Using this incorrect command:
docker exec -i deluge deluge-console -c /config "config --set listen_ports 50000 50000"
I got a message like this:
Setting "listen_ports" to: ('9', '9', '9', '9', '9', ' ', '9', '9', '9', '9', '9')
The port argument was interpreted as an array of characters. The correct format is to wrap in parentheses and comma-separate. (1234, 1234) instead of 1234 1234.
Setup
Install file watcher
sudo apt install inotify-tools
Create the deluge-port-watcher.sh script
In /home/MY_HOME/deluge-port-watcher/deluge-port-watcher.sh
#!/bin/bash
PORTFILE="/home/MY_HOME/protonvpn/tmp/forwarded_port"
PORTDIR="$(dirname "$PORTFILE")"
PORTNAME="$(basename "$PORTFILE")"
update_port() {
if [[ -f "$PORTFILE" ]]; then
port=$(cat "$PORTFILE")
logger -t deluge-port-watcher "Setting Deluge listen port to $port"
docker exec -i deluge deluge-console -c /config "config --set listen_ports ($port, $port)"
else
logger -t deluge-port-watcher "Port file missing: $PORTFILE"
fi
}
# Update Deluge on startup
update_port
# Watch parent directory for changes to our port file. This is required because docker moves
# the file instead of updating it in place. So we watch the parent directory and make
# the update only if the event is for the file we care about.
inotifywait -m -e close_write,move,create "$PORTDIR" | \
while read -r directory events filename; do
if [[ "$filename" == "$PORTNAME" ]]; then
update_port
fi
done
Make sure this file uses unix-style line endings
Make the script executable
sudo chmod +x /home/MY_HOME/deluge-port-watcher/deluge-port-watcher.sh
Create systemd service
Create this file /etc/systemd/system/deluge-port-watcher.service
[Unit]
Description=Deluge Port Watcher
After=docker.service
[Service]
Type=simple
ExecStart=/home/MY_HOME/deluge-port-watcher/deluge-port-watcher.sh
Restart=on-failure
[Install]
WantedBy=multi-user.target
Reload and start the service
sudo systemctl daemon-reload
sudo systemctl enable --now deluge-port-watcher
Watch logs
sudo journalctl -u deluge-port-watcher
Test
Manually change the forwarded port file to an arbitrary value. Confirm the change took effect in the Deluge UI, then change it back.