LogSeqDB/pages/Tech/NixOS/Articles/Install NixOS on Oracle Cloud over Ubuntu 18.04.sync-conflict-20250817-085627-UULL5XD.md

created, tags, source, author

created	tags	source	author
2023-12-10T12:53:42 (UTC -05:00)	nixos	https://gist.github.com/misuzu/89fb064a2cc09c6a75dc9833bb3995bf	misuzu

• Install NixOS on Oracle Cloud over Ubuntu 18.04

  Excerpt

  Install NixOS on Oracle Cloud over Ubuntu 18.04. GitHub Gist: instantly share code, notes, and snippets.

  ---

• Install NixOS on Oracle Cloud over Ubuntu 18.04 (make sure to use Ubuntu 18.04 or this may not work)

  # install useful tools
  sudo apt-get update
  sudo apt-get install --no-install-recommends -y nano mc git
  
  # prepare /boot
  sudo umount /boot/efi
  sudo mv /boot /boot.bak
  sudo mkdir /boot/
  sudo mount /dev/sda15 /boot
  sudo mv /boot/* /boot.bak/efi/
  
  # use swap file
  sudo dd if=/dev/zero of=/swapfile bs=1M count=1024 status=progress
  sudo chmod 600 /swapfile
  sudo mkswap /swapfile
  sudo swapon /swapfile
  
  # install nix
  sh <(curl -L https://nixos.org/nix/install)
  . $HOME/.nix-profile/etc/profile.d/nix.sh
  nix-channel --add https://nixos.org/channels/nixos-21.11 nixpkgs
  nix-channel --update
  
  # install nixos-generate-config and nixos-install
  nix-env -f '<nixpkgs>' -iA nixos-install-tools
  
  # generate config
  sudo `which nixos-generate-config` --root /
  
  # remove lxc mounts
  sudo nano /etc/nixos/hardware-configuration.nix
  # set hostname, add users and ssh-keys, enable openssh
  sudo nano /etc/nixos/configuration.nix
  
  # build config
  nix-env -p /nix/var/nix/profiles/system -f '<nixpkgs/nixos>' -I nixos-config=/etc/nixos/configuration.nix -iA system
  
  # prepare target
  sudo chown -R 0.0 /nix
  sudo touch /etc/NIXOS
  sudo touch /etc/NIXOS_LUSTRATE
  echo etc/nixos | sudo tee -a /etc/NIXOS_LUSTRATE
  
  # install NixOS
  sudo NIXOS_INSTALL_BOOTLOADER=1 /nix/var/nix/profiles/system/bin/switch-to-configuration boot
  
  sudo reboot
  

• Recommended configuration options

  {
    # Oracle Cloud uses EFI boot
    boot.loader.systemd-boot.enable = true;
    boot.loader.efi.canTouchEfiVariables = true;
  
    # Kernel cmdline from Ubuntu config
    boot.kernelParams = [
      "console=ttyS0"
      "console=tty1"
      "nvme.shutdown_timeout=10"
      "libiscsi.debug_libiscsi_eh=1"
    ];
  
    # Load graphics driver in stage 1
    boot.initrd.kernelModules = [ "bochs_drm" ];
  
    # swap file is recommended
    swapDevices = [
      {
        device = "/swapfile";
        priority = 0;
      }
    ];
  }
  

• Repartitioning target system from kexec image

  Create kexec.nix file with following contents (do not add any packages to environment.systemPackages or it won't boot on 1GB system):

  { config, pkgs, ... }:
  {
    imports = [
      # this will work only under qemu, uncomment next line for full image
      # <nixpkgs/nixos/modules/installer/netboot/netboot-minimal.nix>
      <nixpkgs/nixos/modules/installer/netboot/netboot.nix>
      <nixpkgs/nixos/modules/profiles/qemu-guest.nix>
    ];
  
    # stripped down version of https://github.com/cleverca22/nix-tests/tree/master/kexec
    system.build = rec {
      image = pkgs.runCommand "image" { buildInputs = [ pkgs.nukeReferences ]; } ''
        mkdir $out
        cp ${config.system.build.kernel}/${config.system.boot.loader.kernelFile} $out/kernel
        cp ${config.system.build.netbootRamdisk}/initrd $out/initrd
        nuke-refs $out/kernel
      '';
      kexec_script = pkgs.writeTextFile {
        executable = true;
        name = "kexec-nixos";
        text = ''
          #!${pkgs.stdenv.shell}
          set -e
          ${pkgs.kexectools}/bin/kexec -l ${image}/kernel --initrd=${image}/initrd --append="init=${builtins.unsafeDiscardStringContext config.system.build.toplevel}/init ${toString config.boot.kernelParams}"
          sync
          echo "executing kernel, filesystems will be improperly umounted"
          ${pkgs.kexectools}/bin/kexec -e
        '';
      };
      kexec_tarball = pkgs.callPackage <nixpkgs/nixos/lib/make-system-tarball.nix> {
        storeContents = [
          {
            object = config.system.build.kexec_script;
            symlink = "/kexec_nixos";
          }
        ];
        contents = [ ];
        compressCommand = "cat";
        compressionExtension = "";
      };
      kexec_tarball_self_extract_script = pkgs.writeTextFile {
        executable = true;
        name = "kexec-nixos";
        text = ''
          #!/bin/sh
          set -eu
          ARCHIVE=`awk '/^__ARCHIVE_BELOW__/ { print NR + 1; exit 0; }' $0`
          tail -n+$ARCHIVE $0 | tar x -C /
          /kexec_nixos $@
          exit 1
          __ARCHIVE_BELOW__
        '';
      };
      kexec_bundle = pkgs.runCommand "kexec_bundle" { } ''
        cat \
          ${kexec_tarball_self_extract_script} \
          ${kexec_tarball}/tarball/nixos-system-${kexec_tarball.system}.tar \
          > $out
        chmod +x $out
      '';
    };
  
    boot.initrd.availableKernelModules = [ "ata_piix" "uhci_hcd" ];
    boot.kernelParams = [
      "panic=30" "boot.panic_on_fail" # reboot the machine upon fatal boot issues
      "console=ttyS0" # enable serial console
      "console=tty1"
    ];
    boot.kernel.sysctl."vm.overcommit_memory" = "1";
  
    environment.systemPackages = with pkgs; [ cryptsetup ];
    environment.variables.GC_INITIAL_HEAP_SIZE = "1M";
  
    networking.hostName = "kexec";
  
    services.getty.autologinUser = "root";
    services.openssh = {
      enable = true;
      challengeResponseAuthentication = false;
      passwordAuthentication = false;
    };
  
    documentation.enable = false;
    documentation.nixos.enable = false;
    fonts.fontconfig.enable = false;
    programs.bash.enableCompletion = false;
    programs.command-not-found.enable = false;
    security.polkit.enable = false;
    security.rtkit.enable = pkgs.lib.mkForce false;
    services.udisks2.enable = false;
    i18n.supportedLocales = [ (config.i18n.defaultLocale + "/UTF-8") ];
  
    users.users.root.openssh.authorizedKeys.keys = [
      # add your ssh key here
      "ssh-ed25519 ...."
    ];
  }
  

  Build kexec image (you'll need nix/NixOS installed on your machine):

  nix-build '<nixpkgs/nixos>' -A config.system.build.kexec_bundle -I nixos-config=./kexec.nix
  

  Copy tarball to remote machine using scp and reboot into kexec image:

  scp ./result ubuntu@somehost:/tmp/kexec
  ssh ubuntu@somehost -t sudo /tmp/kexec
  # wait for machine to boot and then connect
  ssh root@somehost
  

  Repartition your drive, format, mount file systems, create swap(file) and activate it as soon as possible. Check manual for more info.