This Docker image provides a simple way to establish (and maintain) ssh tunnels. It uses autossh to manage the SSH connection.
docker run --rm -it -p 3000:3000 -v /path/to/id_rsa:/ssh_identity jeroenj/ssh-tunnel 0.0.0.0:3000:localhost:3000 user@example.comThis will establish an SSH connection to example.com as the user user. The port 3000 on localhost (on example.com) will be tunneled to port 3000. Port 3000 is then mapped to port 3000 on the Docker host.
An SSH key can be used in order for authentication which can be mounted as a volume at /ssh_identity. Make sure it's mode is set to 0600.