disko/lib/make-disk-image.nix

172 lines
5.5 KiB
Nix

{ nixosConfig
, diskoLib
, pkgs ? nixosConfig.pkgs
, lib ? pkgs.lib
, name ? "${nixosConfig.config.networking.hostName}-disko-images"
, extraPostVM ? ""
, checked ? false
}:
let
vmTools = pkgs.vmTools.override {
rootModules = ["9p" "9pnet_virtio" "virtio_pci" "virtio_blk"] ++ nixosConfig.config.disko.extraRootModules;
kernel = pkgs.aggregateModules
(with nixosConfig.config.boot.kernelPackages; [ kernel ]);
};
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
parted # for partprobe
systemdMinimal
nix
util-linux
] ++ nixosConfig.config.disko.extraDependencies;
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: "mv ${disk.name}.raw \"$out\"/${disk.name}.raw") (lib.attrValues nixosConfig.config.disko.devices.disk)}
${extraPostVM}
'';
partitioner = ''
# 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
${pkgs.systemdMinimal}/lib/systemd/systemd-udevd --daemon
partprobe
udevadm trigger --action=add
udevadm settle
# populate nix db, so nixos-install doesn't complain
export NIX_STATE_DIR=$TMPDIR/state
nix-store --load-db < ${pkgs.closureInfo {
rootPaths = [ systemToInstall.config.system.build.toplevel ];
}}/registration
${systemToInstall.config.system.build.diskoScript}
'';
installer = ''
${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 = vmTools.runInLinuxVM (pkgs.runCommand name
{
buildInputs = dependencies;
inherit preVM postVM QEMU_OPTS;
memSize = nixosConfig.config.disko.memSize;
}
(partitioner + installer));
impure = diskoLib.writeCheckedBash { inherit checked pkgs; } name ''
set -efu
export PATH=${lib.makeBinPath dependencies}
showUsage() {
cat <<\USAGE
Usage: $script [options]
Options:
* --pre-format-files <src> <dst>
copies the src to the dst on the VM, before disko is run
This is useful to provide secrets like LUKS keys, or other files you need for formating
* --post-format-files <src> <dst>
copies the src to the dst on the finished image
These end up in the images later and is useful if you want to add some extra stateful files
They will have the same permissions but will be owned by root:root
* --build-memory <amt>
specify the ammount of memory that gets allocated to the build vm (in mb)
This can be usefull if you want to build images with a more involed NixOS config
By default the vm will get 1024M/1GB
USAGE
}
export out=$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
;;
--build-memory)
regex="^[0-9]+$"
if ! [[ $2 =~ $regex ]]; then
echo "'$2' is not a number"
exit 1
fi
build_memory=$2
shift 1
;;
*)
showUsage
exit 1
;;
esac
shift
done
export preVM=${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
[ -e "$src" ] || continue
dst=$(basename "$src" | base64 -d)
mkdir -p "$(dirname "$dst")"
cp -r "$src" "$dst"
done
set -f
${partitioner}
set +f
for src in /tmp/xchg/copy_after_disko/*; do
[ -e "$src" ] || continue
dst=/mnt/$(basename "$src" | base64 -d)
mkdir -p "$(dirname "$dst")"
cp -r "$src" "$dst"
done
${installer}
''}
build_memory=''${build_memory:-1024}
QEMU_OPTS=${lib.escapeShellArg QEMU_OPTS}
QEMU_OPTS+=" -m $build_memory"
export QEMU_OPTS
${pkgs.bash}/bin/sh -e ${vmTools.vmRunCommand vmTools.qemuCommandLinux}
cd /
'';
}