Syncthing Relay Docker Image
Syncthing Relay to help Syncthing clients relay data when they can't communicate directly due to things like NAT routers and firewalls blocking inbound TCP connections.
More detailed description on my blog.
Extensively tested on Digital Ocean $5/mo node
docker run --rm -p 22067:22067 -p 22070:22070 kylemanna/syncthing-relay
Verify your server shows up at http://relays.syncthing.net/
Using Systemd to Auto Start the Docker Container
Here's the quick start guide for setting up a systemd service that will listen on the defualt ports and start at boot time. It will also attempt to pull down image updates each time the service starts and automatically restart after 10 seconds if the process exits. This Docker container preserves no state across starts.
cd /etc/systemd/system sudo curl -O https://raw.githubusercontent.com/kylemanna/docker-syncthing-relay/master/init/docker-syncthing-relay.service sudo systemctl daemon-reload sudo systemctl enable --now docker-syncthing-relay.service sudo systemctl status docker-syncthing-relay.service