nixos-images/nix/kexec-installer/module.nix
2023-05-07 21:06:12 +02:00

124 lines
4.1 KiB
Nix

{ config, lib, modulesPath, pkgs, ... }:
let
restore-network = pkgs.writers.writePython3 "restore-network" {
flakeIgnore = ["E501"];
} ./restore_routes.py;
# does not link with iptables enabled
iprouteStatic = pkgs.pkgsStatic.iproute2.override { iptables = null; };
in {
imports = [
(modulesPath + "/installer/netboot/netboot-minimal.nix")
];
options = {
system.kexec-installer.name = lib.mkOption {
type = lib.types.str;
default = "nixos-kexec-installer";
description = ''
The variant of the kexec installer to use.
'';
};
};
config = {
# We are stateless, so just default to latest.
system.stateVersion = config.system.nixos.version;
# This is a variant of the upstream kexecScript that also allows embedding
# a ssh key.
system.build.kexecRun = pkgs.runCommand "kexec-run" {} ''
install -D -m 0755 ${./kexec-run.sh} $out
sed -i \
-e 's|@init@|${config.system.build.toplevel}/init|' \
-e 's|@kernelParams@|${lib.escapeShellArgs config.boot.kernelParams}|' \
$out
${pkgs.shellcheck}/bin/shellcheck $out
'';
system.build.kexecTarball = pkgs.runCommand "kexec-tarball" {} ''
mkdir kexec $out
cp "${config.system.build.netbootRamdisk}/initrd" kexec/initrd
cp "${config.system.build.kernel}/${config.system.boot.loader.kernelFile}" kexec/bzImage
cp "${config.system.build.kexecRun}" kexec/run
cp "${pkgs.pkgsStatic.kexec-tools}/bin/kexec" kexec/kexec
cp "${iprouteStatic}/bin/ip" kexec/ip
tar -czvf $out/${config.system.kexec-installer.name}-${pkgs.stdenv.hostPlatform.system}.tar.gz kexec
'';
# IPMI SOL console redirection stuff
boot.kernelParams =
[ "console=tty0" ] ++
(lib.optional (pkgs.stdenv.hostPlatform.isAarch32 || pkgs.stdenv.hostPlatform.isAarch64) "console=ttyAMA0,115200") ++
(lib.optional (pkgs.stdenv.hostPlatform.isRiscV) "console=ttySIF0,115200") ++
[ "console=ttyS0,115200" ];
documentation.enable = false;
# Not really needed. Saves a few bytes and the only service we are running is sshd, which we want to be reachable.
networking.firewall.enable = false;
systemd.network.enable = true;
networking.dhcpcd.enable = false;
# for detection if we are on kexec
environment.etc.is_kexec.text = "true";
# for zapping of disko
environment.systemPackages = [
pkgs.jq
];
systemd.services.restore-network = {
before = [ "network-pre.target" ];
wants = [ "network-pre.target" ];
wantedBy = [ "multi-user.target" ];
serviceConfig = {
Type = "oneshot";
RemainAfterExit = true;
ExecStart = [
"${restore-network} /root/network/addrs.json /root/network/routes-v4.json /root/network/routes-v6.json /etc/systemd/network"
];
};
unitConfig.ConditionPathExists = [
"/root/network/addrs.json"
"/root/network/routes-v4.json"
"/root/network/routes-v6.json"
];
};
systemd.services.log-network-status = {
wantedBy = [ "multi-user.target" ];
# No point in restarting this. We just need this after boot
restartIfChanged = false;
serviceConfig = {
Type = "oneshot";
StandardOutput = "journal+console";
ExecStart = [
# Allow failures, so it still prints what interfaces we have even if we
# not get online
"-${pkgs.systemd}/lib/systemd/systemd-networkd-wait-online"
"${pkgs.iproute2}/bin/ip -c addr"
"${pkgs.iproute2}/bin/ip -c -6 route"
"${pkgs.iproute2}/bin/ip -c -4 route"
];
};
};
# Restore ssh host and user keys if they are available.
# This avoids warnings of unknown ssh keys.
boot.initrd.postMountCommands = ''
mkdir -m 700 -p /mnt-root/root/.ssh
mkdir -m 755 -p /mnt-root/etc/ssh
mkdir -m 755 -p /mnt-root/root/network
if [[ -f ssh/authorized_keys ]]; then
install -m 400 ssh/authorized_keys /mnt-root/root/.ssh
fi
install -m 400 ssh/ssh_host_* /mnt-root/etc/ssh
cp *.json /mnt-root/root/network/
'';
};
}