Simple micro service returning the caller's IP over http (intended for dynamic dns use cases). An example DynDNS client can be found here: https://github.com/AwareRO/owndyndns.
go build ipecho.go
# edit backend.toml.sample
mkdir /etc/ipecho
cp backend.toml.sample /etc/ipecho/backend.toml
./ipecho [custom-config.toml]
# build
cp ipecho /usr/bin
cp ipecho.service /etc/systemd/system
systemctl daemon-reload
systemctl enable ipecho
systemctl start ipecho
journalctl -f -u ipecho