nixos/installer: add kexec-boot

This module exposes a config.system.build.kexecBoot attribute,
which returns a directory with kernel, initrd and a shell script
running the necessary kexec commands.

It's meant to be scp'ed to a machine with working ssh and kexec binary
installed.

This is useful for (cloud) providers where you can't boot a custom image, but
get some Debian or Ubuntu installation.
This commit is contained in:
Florian Klink 2022-02-21 17:41:34 +01:00 committed by lassulus
parent 1730f14d79
commit 366c8be2ad

View file

@ -0,0 +1,50 @@
# This module exposes a config.system.build.kexecBoot attribute,
# which returns a directory with kernel, initrd and a shell script
# running the necessary kexec commands.
# It's meant to be scp'ed to a machine with working ssh and kexec binary
# installed.
# This is useful for (cloud) providers where you can't boot a custom image, but
# get some Debian or Ubuntu installation.
{ pkgs
, modulesPath
, config
, ...
}:
{
imports = [
(modulesPath + "/installer/netboot/netboot-minimal.nix")
];
config = {
system.build.kexecBoot =
let
kexecScript = pkgs.writeScript "kexec-boot" ''
#!/usr/bin/env bash
if ! kexec -v >/dev/null 2>&1; then
echo "kexec not found: please install kexec-tools" 2>&1
exit 1
fi
kexec --load ./bzImage \
--initrd=./initrd.gz \
--command-line "init=${config.system.build.toplevel}/init ${toString config.boot.kernelParams}"
kexec -e
''; in
pkgs.linkFarm "kexec-tree" [
{
name = "initrd.gz";
path = "${config.system.build.netbootRamdisk}/initrd";
}
{
name = "bzImage";
path = "${config.system.build.kernel}/bzImage";
}
{
name = "kexec-boot";
path = kexecScript;
}
];
};
}