How to use ProxyJump with SSH

Originally posted on blog.ruanbekker.com

I have a dedicated server with LXD installed where I have a bunch of system containers running to host a lot of my playground services, and to access the operating system of those lxc containers, I need to SSH to the LXD host, then exec or ssh into that LXC container.

This became tedious and wanted a way to directly ssh to them, as they don't have public ip addresses, it's not possible but found its possible to access them using proxyjump.

[you] -> [hypervisor] -> [vm on hypervisor]

First step is to create our ssh key:

$ ssh-keygen -t rsa

Add the created public key (~/.ssh/id_rsa.pub) on the hypervisor and the target vm's ~/.ssh/authorized_key files.

Then create the SSH Config on your local workstation (~/.ssh/config):

Host *
  StrictHostKeyChecking no
  UserKnownHostsFile=/dev/null

Host hypervisor
  Hostname hv.domain.com
  User myuser
  IdentityFile ~/.ssh/id_rsa

Host ctr1
  Hostname 10.37.117.132
  User root
  IdentityFile ~/.ssh/id_rsa
  ProxyJump hypervisor

Now accessing our lxc container ctr1, is possible by doing:

$ ssh ctr1
Warning: Permanently added 'x,x' (ECDSA) to the list of known hosts.
Warning: Permanently added '10.37.117.132' (ECDSA) to the list of known hosts.
root@ctr1~ $

Thank you for reading