disko/lib/make-disk-image.nix
2023-08-11 08:45:46 +00:00

141 lines
4.4 KiB
Nix

{ nixosConfig
, diskoLib
, pkgs ? nixosConfig.pkgs
, lib ? pkgs.lib
, name ? "${nixosConfig.config.networking.hostName}-disko-images"
, extraPostVM ? ""
, checked ? false
}:
let
cleanedConfig = diskoLib.testLib.prepareDiskoConfig nixosConfig.config diskoLib.testLib.devices;
systemToInstall = nixosConfig.extendModules {
modules = [{
disko.devices = lib.mkForce cleanedConfig.disko.devices;
boot.loader.grub.devices = lib.mkForce cleanedConfig.boot.loader.grub.devices;
}];
};
dependencies = with pkgs; [
bash
coreutils
gnused
systemdMinimal
nix
utillinux
];
preVM = ''
${lib.concatMapStringsSep "\n" (disk: "truncate -s ${disk.imageSize} ${disk.name}.raw") (lib.attrValues nixosConfig.config.disko.devices.disk)}
'';
postVM = ''
# shellcheck disable=SC2154
mkdir -p "$out"
${lib.concatMapStringsSep "\n" (disk: "cp ${disk.name}.raw \"$out\"/${disk.name}.raw") (lib.attrValues nixosConfig.config.disko.devices.disk)}
${extraPostVM}
'';
builder = ''
# running udev, stolen from stage-1.sh
echo "running udev..."
ln -sfn /proc/self/fd /dev/fd
ln -sfn /proc/self/fd/0 /dev/stdin
ln -sfn /proc/self/fd/1 /dev/stdout
ln -sfn /proc/self/fd/2 /dev/stderr
mkdir -p /etc/udev
ln -sfn ${systemToInstall.config.system.build.etc}/etc/udev/rules.d /etc/udev/rules.d
mkdir -p /dev/.mdadm
${pkgs.systemdMinimal}/lib/systemd/systemd-udevd --daemon
udevadm trigger --action=add
udevadm settle
# populate nix db, so nixos-install doesn't complain
export NIX_STATE_DIR=$TMPDIR/state
nix-store --load-db < ${pkgs.closureInfo {
rootPaths = [ systemToInstall.config.system.build.toplevel ];
}}/registration
${systemToInstall.config.system.build.diskoScript}
${systemToInstall.config.system.build.nixos-install}/bin/nixos-install --system ${systemToInstall.config.system.build.toplevel} --keep-going --no-channel-copy -v --no-root-password --option binary-caches ""
'';
QEMU_OPTS = lib.concatMapStringsSep " " (disk: "-drive file=${disk.name}.raw,if=virtio,cache=unsafe,werror=report") (lib.attrValues nixosConfig.config.disko.devices.disk);
in
{
pure = pkgs.vmTools.runInLinuxVM (pkgs.runCommand name
{
buildInputs = dependencies;
inherit preVM QEMU_OPTS;
memSize = 1024;
}
builder);
impure = diskoLib.writeCheckedBash { inherit checked pkgs; } name ''
set -efu
export PATH=${lib.makeBinPath dependencies}
showUsage() {
cat <<\USAGE
Usage: $script [options]
Options:
* --pre-format-files <src> <dst>
copies the src to the dst on the VM, before disko is run
This is useful to provide secrets like LUKS keys, or other files you need for formating
* --post-format-files <src> <dst>
copies the src to the dst on the finished image.
These end up in the images later and is useful if you want to add some extra stateful files
USAGE
}
export out=$PWD
TMPDIR=$(mktemp -d); export TMPDIR
trap 'rm -rf "$TMPDIR"' EXIT
cd "$TMPDIR"
mkdir copy_before_disko copy_after_disko
while [[ $# -gt 0 ]]; do
case "$1" in
--pre-format-files)
src=$2
dst=$3
cp --reflink=auto -r "$src" copy_before_disko/"$(echo "$dst" | base64)"
shift 2
;;
--post-format-files)
src=$2
dst=$3
cp --reflink=auto -r "$src" copy_after_disko/"$(echo "$dst" | base64)"
shift 2
;;
*)
showUsage
exit 1
;;
esac
shift
done
export preVM=${diskoLib.writeCheckedBash { inherit pkgs checked; } "preVM.sh" ''
set -efu
mv copy_before_disko copy_after_disko xchg/
${preVM}
''}
export postVM=${diskoLib.writeCheckedBash { inherit pkgs checked; } "postVM.sh" postVM}
export origBuilder=${pkgs.writeScript "disko-builder" ''
set -eu
export PATH=${lib.makeBinPath dependencies}
for src in /tmp/xchg/copy_before_disko/*; do
dst=$(basename "$src" | base64 -d)
mkdir -p "$(dirname "$dst")"
cp -r "$src" "$dst"
done
set -f
${builder}
set +f
for dir in /tmp/xchg/copy_after_disko/*; do
dst=/mnt/$(basename "$src" | base64 -d)
mkdir -p "$(dirname "$dst")"
cp -r "$src" "$dst"
done
''}
export QEMU_OPTS=${lib.escapeShellArg "${QEMU_OPTS} -m 1024"}
${pkgs.bash}/bin/sh -e ${pkgs.vmTools.vmRunCommand pkgs.vmTools.qemuCommandLinux}
cd /
'';
}