nixpkgs/nixos/modules/virtualisation/oci-image.nix

{ config, lib, pkgs, ... }:

{
  imports = [ ./oci-common.nix ];

  config = {
    system.build.OCIImage = import ../../lib/make-disk-image.nix {
      inherit config lib pkgs;
      name = "oci-image";
      configFile = ./oci-config-user.nix;
      format = "qcow2";
      diskSize = 8192;
    };

    systemd.services.fetch-ssh-keys = {
      description = "Fetch authorized_keys for root user";

      wantedBy = [ "sshd.service" ];
      before = [ "sshd.service" ];

      after = [ "network-online.target" ];
      wants = [ "network-online.target" ];

      path  = [ pkgs.coreutils pkgs.curl ];
      script = ''
        mkdir -m 0700 -p /root/.ssh
        if [ -f /root/.ssh/authorized_keys ]; then
          echo "Authorized keys have already been downloaded"
        else
          echo "Downloading authorized keys from Instance Metadata Service v2"
          curl -s -S -L \
            -H "Authorization: Bearer Oracle" \
            -o /root/.ssh/authorized_keys \
            http://169.254.169.254/opc/v2/instance/metadata/ssh_authorized_keys
          chmod 600 /root/.ssh/authorized_keys
        fi
      '';
      serviceConfig = {
        Type = "oneshot";
        RemainAfterExit = true;
        StandardError = "journal+console";
        StandardOutput = "journal+console";
      };
    };
  };
}