Passage - SSH tunnels on steroids 
Passage is a moderm SSH tunneling tool, build on Go.
Passage server allows you to have multiple SSH tunnels over the same SSH connection or several SSH connections, also allows to make easy connections to Docker containers without exported ports, along other features.
ok but what for is a SSH tunnel ...
A SSH tunnel forward a specified local port to a port on the remote machine with the only requirement of having a working SSH connection.
This can be done easily using a basic command on any *nix machine like ssh example.com -L 80:localhost:80 -N
Installation
wget https://github.com/mcuadros/passage/releases/download/v0.1.0/passage_v0.1.0_linux_amd64.tar.gz
tar -xvzf passage_v0.1.0_linux_amd64.tar.gz
cp passage_v0.1.0_linux_amd64/passage /usr/local/bin/
browse the releases section to see other archs and versions
License
MIT, see LICENSE