[Arnavion]

The API for creating Azure VMs doesn't support specifying an ED25519 key.

https://docs.microsoft.com/en-us/azure/virtual-machines/linu...

But once you've created the VM you can log in and replace that RSA key with an ED25519 one just like any standard Linux install, via ssh-copy-id or manually updating authorized_keys or whatever you want. So you just need a throwaway RSA key for the initial deployment.

[milliams]

Thanks for the information. That's pretty embarrassing that it's still not supported.

[pritambaral]

If Azure supports cloud-init, you can forego that throwaway RSA key.