89 lines
3 KiB
Nix
89 lines
3 KiB
Nix
{ config, lib, modulesPath, pkgs, ... }:
|
|
{
|
|
imports = [
|
|
(modulesPath + "/installer/netboot/netboot-minimal.nix")
|
|
];
|
|
|
|
# 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 = lib.mkForce (pkgs.writeScript "kexec-run" ''
|
|
#!/usr/bin/env bash
|
|
set -ex
|
|
shopt -s nullglob
|
|
SCRIPT_DIR=$( cd -- "$( dirname -- "''${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
|
|
INITRD_TMP=$(mktemp -d)
|
|
cd "$INITRD_TMP"
|
|
pwd
|
|
mkdir -p initrd/ssh
|
|
pushd initrd
|
|
if [ -e /root/.ssh/authorized_keys ]; then
|
|
cat /root/.ssh/authorized_keys >> ssh/authorized_keys
|
|
fi
|
|
if [ -e /etc/ssh/authorized_keys.d/root ]; then
|
|
cat /etc/ssh/authorized_keys.d/root >> ssh/authorized_keys
|
|
fi
|
|
for p in /etc/ssh/ssh_host_*; do
|
|
cp -a "$p" ssh
|
|
done
|
|
find | cpio -o -H newc | gzip -9 > ../extra.gz
|
|
popd
|
|
cat "''${SCRIPT_DIR}/initrd.gz" extra.gz > final.gz
|
|
|
|
"$SCRIPT_DIR/kexec" --load "''${SCRIPT_DIR}/bzImage" \
|
|
--initrd=final.gz \
|
|
--command-line "init=${config.system.build.toplevel}/init ${toString config.boot.kernelParams}"
|
|
|
|
# kexec will map the new kernel in memory so we can remove the kernel at this point
|
|
rm -r "$INITRD_TMP"
|
|
|
|
# Disconnect our background kexec from the terminal
|
|
if [[ -e /dev/kmsg ]]; then
|
|
# this makes logging visible in `dmesg`, or the system consol or tools like journald
|
|
exec > /dev/kmsg 2>&1
|
|
else
|
|
exec > /dev/null 2>&1
|
|
fi
|
|
# We will kexec in background so we can cleanly finish the script before the hosts go down.
|
|
# This makes integration with tools like terraform easier.
|
|
nohup bash -c "sleep 6 && '$SCRIPT_DIR/kexec' -e" &
|
|
'');
|
|
|
|
system.build.kexecTarball = pkgs.callPackage (pkgs.path + "/nixos/lib/make-system-tarball.nix") {
|
|
fileName = "nixos-kexec-installer-${pkgs.stdenv.hostPlatform.system}";
|
|
contents = [
|
|
{
|
|
target = "/kexec/initrd.gz";
|
|
source = "${config.system.build.netbootRamdisk}/initrd";
|
|
}
|
|
{
|
|
target = "/kexec/bzImage";
|
|
source = "${config.system.build.kernel}/${config.system.boot.loader.kernelFile}";
|
|
}
|
|
{
|
|
target = "/kexec/run";
|
|
source = config.system.build.kexecRun;
|
|
}
|
|
{
|
|
target = "/kexec/kexec";
|
|
source = "${pkgs.pkgsStatic.kexec-tools}/bin/kexec";
|
|
}
|
|
];
|
|
};
|
|
|
|
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;
|
|
|
|
# Restore ssh host and user keys if they are available.
|
|
# This avoids warnings of unknown ssh keys.
|
|
boot.initrd.postMountCommands = ''
|
|
mkdir -p /mnt-root/etc/ssh /mnt-root/root/.ssh
|
|
if [[ -f /ssh/authorized_keys ]]; then
|
|
cp ssh/authorized_keys /mnt-root/root/.ssh/
|
|
fi
|
|
cp ssh/ssh_host_* /mnt-root/etc/ssh
|
|
'';
|
|
}
|