fruitbasket/modules/core/initrd-ssh.nix

# Find the required kernel module for the network adapter using `lspci -v` and add it to `boot.initrd.availableKernelModules`.
# Enable `networking.useDHCP` or set a static ip using the `ip=` kernel parameter.
# Generate another SSH host key for the machine:
# $ ssh-keygen -t ed25519 -N "" -f /etc/ssh/ssh_host_ed25519_key_initrd -C HOSTNAME-initrd
# Add the public key to your known_hosts and create an ssh config entry.
{ config, ... }:
{
  boot.initrd = {
    systemd = {
      enable = true;
      network = {
        enable = true;
        networks."10-wired-default" = config.systemd.network.networks."10-wired-default";
      };
      users.root.shell = "/bin/zfs load-key rpool/nixos";
    };
    network = {
      enable = true;
      ssh = {
        enable = true;
        port = 222;
        hostKeys = [ "/etc/ssh/ssh_host_ed25519_key_initrd" ];
        # authorizedKeys option inherits root's authorizedKeys.keys, but not keyFiles
      };
    };
  };
}