anchor.diff:  
         # Let's install our client private key
         $machine->succeed("mkdir -p ~/.ssh");
  -      ${concatMapStrings (s: "$machine->succeed('echo ${s} >> ~/.ssh/id_ecdsa');") snakeOilPrivateKey}
  -      $machine->succeed("chmod 600 ~/.ssh/id_ecdsa");
  +
  +      $machine->succeed("echo '${snakeOilPrivateKey}' > ~/.ssh/id_ed25519");
  +      $machine->succeed("chmod 600 ~/.ssh/id_ed25519");
   
         # We haven't configured the host key yet, so this should still fail
         $machine->fail("ssh -o BatchMode=yes localhost exit");
  
positive.code:       nodes = {};
        testScript =
          ''
            use File::Temp qw/ tempfile /;
            my ($fh, $filename) = tempfile();
  
            `qemu-img create -f qcow2 -o backing_file=${image}/nixos.img $filename`;
  
            my $startCommand = "qemu-kvm -m 768 -net nic -net 'user,net=169.254.0.0/16,guestfwd=tcp:169.254.169.254:80-cmd:${pkgs.micro-httpd}/bin/micro_httpd ${metaData}'";
            $startCommand .= " -drive file=" . Cwd::abs_path($filename) . ",if=virtio,werror=report";
            $startCommand .= " \$QEMU_OPTS";
  
            my $machine = createMachine({ startCommand => $startCommand });
            ${script}
          '';
      };
  
    snakeOilPrivateKey = [
      "-----BEGIN EC PRIVATE KEY-----"
      "MHcCAQEEIHQf/khLvYrQ8IOika5yqtWvI0oquHlpRLTZiJy5dRJmoAoGCCqGSM49"
      "AwEHoUQDQgAEKF0DYGbBwbj06tA3fd/+yP44cvmwmHBWXZCKbS+RQlAKvLXMWkpN"
      "r1lwMyJZoSGgBHoUahoYjTh9/sJL7XLJtA=="
      "-----END EC PRIVATE KEY-----"
    ];
  
    snakeOilPublicKey = pkgs.lib.concatStrings [
      "ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHA"
      "yNTYAAABBBChdA2BmwcG49OrQN33f/sj+OHL5sJhwVl2Qim0vkUJQCry1zFpKTa"
      "9ZcDMiWaEhoAR6FGoaGI04ff7CS+1yybQ= snakeoil"
    ];
  in {
    boot-ec2-nixops = makeEc2Test {
      name         = "nixops-userdata";
      sshPublicKey = snakeOilPublicKey; # That's right folks! My user's key is also the host key!
  
      userData = ''
        SSH_HOST_DSA_KEY_PUB:${snakeOilPublicKey}
        SSH_HOST_DSA_KEY:${pkgs.lib.concatStringsSep "|" snakeOilPrivateKey}
      '';
      script = ''
        $machine->start;
  
negative.code:     (import ../lib/eval-config.nix {
        inherit system;
        modules = [
          ../maintainers/scripts/ec2/amazon-image.nix
          ../../nixos/modules/testing/test-instrumentation.nix
          { boot.initrd.kernelModules = [ "virtio" "virtio_blk" "virtio_pci" "virtio_ring" ];
            ec2.hvm = true;
          }
        ];
      }).config.system.build.amazonImage;
  
  