monsoft/ssh-jumpbox repository overview

⁠SSH Docker jumpbox

My idea was to build small docker container which will be acting as Linux jumpbox. This project is based on already exiting one https://github.com/warden/docker-jumpbox⁠ but it has been rewritten and size of image has been reduced.

⁠Starting ssh-docker-jumpbox

This is just general guidance and you don't need to follow it step-by-step. You can user your own build image or use mine. Source code for this container can be find in GitHub repository https://github.com/monsoft/ssh-docker-jumpbox⁠ . There is more description there as well.

⁠Prepare directories

Create directory where 'authorized_keys' file will be stored. I use '/opt/jumpboxX':

$ sudo mkdir -p /opt/jumpbox1

⁠Create authorized_keys

Each user is authenticated by ssh key during login, and to be able to do it, specially 'crafted' file is required. It's like normal authorized_keys file but with username at the beginning. General file format is:

username:ssh_public_key

Created file need to be placed in previously created directory:

/opt/jumpbox1/authorized_keys

⁠Create volume

I prefer to use separated volume to store and preserver users local files.

$ docker volume create jumpbox1

⁠Starting ssh-jumpbox container on single Docker host

When all previous setups are in place, start container:

$ docker run -d --name=jumpbox1 --hostname=jumpbox1 \
    -e USERS="test1 test2" \
    -v /opt/jumpbox1/authorized-keys:/etc/authorized-keys:ro \
    -v jumpbox1:/home \
    -p 1022:22 monsoft/ssh-jumpbox

As USERS variable, we passing usernames for which we created corresponding lines in authorized_keys file.

⁠Starting ssh-jumpbox stack on Docker Swarm

For redundancy/loadbalancing purpose this ssh-jumpbox can be deployed as Docker Stack on Swarm.

⁠Create stack file

Open file 'ssh-jumpbox_compose.yml' in your favourite editor and place below lines into it

version: "3.2"

services:
  ssh-jumpbox1:
    image: monsoft/ssh-jumpbox
    environment:
      USERS: 'test1 test2"'
    ports:
      - "1022:22"
    networks:
      - jumpbox1
    volumes:
      - ssh-jumpbox1:/home
      - /opt/jumpbox1/authorized-keys:/etc/authorized-keys
    deploy:
      mode: replicated
      replicas: 2

volumes:
  ssh-jumpbox1:

networks:
  jumpbox1:
    driver: overlay
    attachable: true

⁠Deploying ssh-jumpbox stack

To deploye ssh-jumpbox stack run below command

$ docker stack deploy -c ssh-jumpbox_compose.yml ssh-jumpbox-dev1

or if you build your own image and pushed it to private Docker Hub repository

$ docker stack deploy -c ssh-jumpbox_compose.yml ssh-jumpbox-dev1 --with-registry-auth