nix-config/machines/kexec.nix

72 lines
2.3 KiB
Nix

# From https://mdleom.com/blog/2021/03/09/nixos-oracle/#Build-a-kexec-tarball
# Builds a kexec img
{ config, pkgs, modulesPath, ... }:
{
imports = [
(modulesPath + "/installer/netboot/netboot.nix")
(modulesPath + "/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
if [ -f ${config.system.build.kernel}/bzImage ]; then
cp ${config.system.build.kernel}/bzImage $out/kernel
else
cp ${config.system.build.kernel}/Image $out/kernel
fi
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 (modulesPath + "/../lib/make-system-tarball.nix") {
storeContents = [
{
object = config.system.build.kexec_script;
symlink = "/kexec_nixos";
}
];
contents = [ ];
};
};
boot.initrd.availableKernelModules = [ "ata_piix" "uhci_hcd" "e1000" "e1000e" "virtio_pci" "r8169" ];
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
btrfs-progs
];
environment.variables.GC_INITIAL_HEAP_SIZE = "1M";
networking.useDHCP = true;
networking.hostName = "kexec";
services.openssh = {
enable = true;
challengeResponseAuthentication = false;
passwordAuthentication = false;
};
services.getty.autologinUser = "root";
users.users.root.openssh.authorizedKeys.keys = (import ../common/ssh.nix).users;
}