OpenSSH based localtunnel.
Get the server image and deploy it on your own server:
# m31271n/channel is the prebuild image's name
docker run -d --network host m31271n/channel -e PASSWORD=<YOUR OWN PASSWORD>
Get the client:
curl https://raw.githubusercontent.com/rekcod/channel/master/channel -o channel && chmod +x channel
Run the client:
# Remote port forward <remote address>:<remote port> to <local port>
channel -a <remote address> -r <remote port> -l <local port>
Inspired by Rodny Rehm.