Using SSH Key Authentication with UpSnap for Remote Shutdown

[Masked-Kunsiquat]

First off - thanks so much for this tool - it's made WoL significantly easier in my HomeLab!

My Setup

• UpSnap (binary version 5.0.4) running on macOS
• managing a Debian Linux server (kernel 6.1.0-28-amd64)
• SSH key-based authentication already configured in my personal environment (works fine in terminal/VS Code)

The Issue

I'm having trouble getting UpSnap to use SSH key-based auth for shutdown commands. I prefer not to use password-based auth for security reasons (and laziness changing all the custom configs 😅)

When i try to use a command like:

SSH_CONFIG_FILE=/Users/username/.ssh/config ssh -F /Users/username/.ssh/config apollo "shutdown -h now"

I get these errors in the logs:

[WARNING] Your command didn't finish in time. It will be killed.
[ERROR] shutdown.go:63: wait: no child processes
[ERROR] handlers.go:108: apollo not offline after 120 seconds

I also tried:

ssh -i /Users/username/.ssh/id_rsa -o "StrictHostKeyChecking=no" [email protected] "shutdown -h now"

But see similar timeout errors.

Questions

• What's the recommend approach for using SSH key auth with UpSnap?
• Does UpSnap support using the system's SSH agent (e.g. I'm leveraging 1Password's ssh agent)?
• How does UpsSnap handle passwords in the shutdown commands? Is it stored in plain-text, etc?
• If UpSnap doesn't support SSH key auth, do you think you would consider supporting it in the future?

I understand sshpass with password auth works, but I'd prefer to stick with key-based auth if possible.

Thanks for any help you can provide!

[rohkaemper]

Hey.

I think you might be on the wrong track. This seems to be an issue with your ssh approach not with upsnap.
I am using upsnap in my homelab too and it works flawlessly with ssh-keys.

How are you running your upsnap instance?

I use a docker based approach.

1. For that to work I had to login to the container docker exec -it <containername> /bin/sh (not sure about whicht shell is available), generate my key (or copy it to it, if you prefer to do so).
2. That newly added key was copied to the host using ssh-copy-id -i ~/.ssh/<keyname> <user>@<11.22.33.44> command.
3. A manual login ssh -i ~/.ssh/<keyname> <user>@<11.22.33.44> was performed to add it to the known_hosts and to check functionality.

After that the command can be used as always:
ssh <user>@<11.22.33.44> poweroff