SSH Tunnel Container on debian:stretch (ghcr.io/servercontainers/sshtunnel) [x86 + arm]

it gives you a hardened ssh configuration where you only allow tcp forwarding to specific ports.

Look at the Docker Compose file.

Can have multiple users with thier own custom configurations

It is roughly based on this informations: https://askubuntu.com/questions/48129/how-to-create-a-restricted-ssh-user-for-port-forwarding

Build & Versions

You can specify DOCKER_REGISTRY environment variable (for example my.registry.tld) and use the build script to build the main container and it's variants for x86_64, arm64 and arm

You'll find all images tagged like d11.2-s1.2.1-2.1 which means d<debian version>-s<openssh-server version (with some esacped chars)>. This way you can pin your installation/configuration to a certian version. or easily roll back if you experience any problems (don't forget to open a issue in that case ;D).

To build a latest tag run ./build.sh release

Changelogs

• 2024-07-06
  • update to debian bookworm
  • fixed build
• 2023-03-20
  • github action to build container
  • implemented ghcr.io as new registry

Environment Variables

• USER_<username>

  • takes ssh public key as argument
  • add a new user and authorize public key
  • e.g. USER_bob: 'ssh-rsa AAAAB3...your.ssh.public.key.here... bob@macbook'

• PERMIT_OPEN_<username>_<permissionname>

  • takes a sshd PermitOpen configuration option as value
  • e.g. PERMIT_OPEN_bob_bbchttp: 'www.bbc.com:80'

all values are able to use multiple values

Establish Port Forwarding using SSH Client

ssh -i ~/.ssh/id_rsa -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -N -L 8080:www.bbc.com:80 bob@127.0.0.1 -p 2222

if you want the command to recover server disconnects/downtimes etc. just encapsulate it whithin while true; do command_from_above; sleep 1; done