This mod adds ssh tunnelling to openssh-server, by enabling tcp forwarding during container start.

In openssh-server docker arguments, set an environment variable DOCKER_MODS=linuxserver/mods:openssh-server-ssh-tunnel

If adding multiple mods, enter them in an array separated by |, such as DOCKER_MODS=linuxserver/mods:openssh-server-ssh-tunnel|linuxserver/mods:openssh-server-mod2

Note: GatewayPorts is set to clientspecified, this moves the responsibility to define the gateway host of the port to the client that opens the tunnel, e.g. *:8080 to forward 8080 to all connection, default is localhost only. In addition it is still necessary to expose the same port on the container level, using either the --expose (only to other containers) or the --port (expose on host level/internet) run options (or the counterparts in docker-compose).

Example:

When creating the container with the following setup:

services:
  openssh-server:
    image: lscr.io/linuxserver/openssh-server
    environment:
      - DOCKER_MODS=linuxserver/mods:openssh-server-ssh-tunnel
      - SHELL_NOLOGIN=false
    volumes:
      - /path/to/appdata/config:/config
    expose:
      - 30000
    ports:
      - 2222:2222

It's possible to expose the client's port 8080 through the container's port 30000 like this:

ssh -R *:30000:localhost:8080 example.com -p 2222

Port 30000 will then only be available to other containers (e.g. a web server acting as a reverse proxy). When using ports instead of expose the port would be accessible from the host (and the network it resides in, e.g. the internet). The client command can be automated using autossh.