SSH into any VM/LXC in Proxmox using a single SSH config block

[orwadira]

Hello everyone,

I have been following the simple formula of using the root Debian PVE system as an SSH jump server to access all of my VMs and LXC containers.

Doing so, I have been using configuration blocks that look like this (for every VM/LXC host):

Host host.proxmox
  Hostname host
  User root
  ProxyJump proxmox
  PreferredAuthentications publickey

For example, host above can be anything, like jenkins, n8n, nextcloud, etc.

In pursuit of a nicer and an easier configuration, I have been looking into ways to use a single configuration block. Initially I tried the following:

Host *.proxmox
  User root
  ProxyCommand echo %h | sed 's/\..*$//' | xargs -I _ ssh -W _:%p -l root proxmox
  PreferredAuthentications publickey

However, this would always lead to the erroneous expansion:

debug1: Executing proxy command: exec echo n8n.proxmox | sed 's/\\..*$//' | xargs -I _ ssh -W _:22 -l root proxmox

... where sed 's/\\..*$//' is not exactly the same as the intended sed 's/\..*$//', leading to a failure in connecting to the host:

debug1: Authenticating to n8n.proxmox:22 as 'root'

(note that the .proxmox suffix in n8n.proxmox was not removed by sed as intended)

I tried many things, and ended up settling on something that I am not happy with and only works in zsh:

Host *.proxmox
  User root
  ProxyCommand ssh -W ${${H:-%h}%%.proxmox}:%p -l root proxmox
  PreferredAuthentications publickey

My request is hence specific, which is, can someone help me make this generic SSH configuration work while being more portable?

Note that I am fully aware of the pct enter and the qm terminal commands...

Hence, if you can come up with an elegant way to use these two subcommands to do what I am trying to do, then please, by all means, go ahead and suggest something. However, please bear in mind that:

1. I want a unified way to SSH into VMs and LXC containers, without having to keep track of which is which.
2. I tend to memorise VMs and LXC containers better using their hostnames, rather than their vmid in Proxmox.
3. I would want a way in which I can still use X11 forwarding (-X) in order to be able to share the clipboard with the host I am SSH'ing to, which to me, is very useful.

Thanks!