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|
# This single-disk approach does not satisfy ZFS's requirements for autoexpand,
# however automation can expand it anyway. For example, with
# `services.zfs.expandOnBoot`.
{
pkgs,
lib,
config,
# size of the FAT partition, in MiB (1024x1024 bytes).
bootSize ? 1024,
# memory allocated for virtualized build instance, in MiB (1024x1024 bytes).
memSize ? 2048,
# The size of the root partition, in MiB (1024x1024 bytes).
rootSize ? 4096,
# Shell code executed after the VM has finished.
postVM ? "",
name ? "nixos-disk-image",
# Disk image format, one of qcow2, qcow2-compressed, vdi, vpc, raw.
format ? "raw",
}:
let
formatOpt = if format == "qcow2-compressed" then "qcow2" else format;
compress = lib.optionalString (format == "qcow2-compressed") "-c";
filenameSuffix =
"."
+ {
qcow2 = "qcow2";
vdi = "vdi";
vpc = "vhd";
raw = "img";
}
.${formatOpt} or formatOpt;
rootFilename = "nixos.root${filenameSuffix}";
closureInfo = pkgs.closureInfo {
rootPaths = [ config.system.build.toplevel ];
};
vmTools = pkgs.vmTools.override {
rootModules = [
"virtio_blk"
"virtio_pci"
"virtiofs"
"zfs"
];
kernel = pkgs.aggregateModules (
with config.boot;
[
kernelPackages.kernel
(lib.getOutput "modules" kernelPackages.kernel)
kernelPackages.${pkgs.zfs.kernelModuleAttribute}
]
);
};
binPath = lib.makeBinPath (
with pkgs;
[
config.system.build.nixos-install
dosfstools
nix
parted
util-linux
zfs
]
++ stdenv.initialPath
);
image = vmTools.runInLinuxVM (
pkgs.runCommand name
{
inherit memSize;
QEMU_OPTS = "-drive file=$rootDiskImage,if=virtio,cache=unsafe,werror=report";
preVM = ''
mkdir $out
rootDiskImage=root.raw
${pkgs.qemu-utils}/bin/qemu-img create -f raw $rootDiskImage ${toString (bootSize + rootSize)}M
'';
postVM = ''
# truncate --size ${toString (bootSize + rootSize)} $rootDiskImage
${
if formatOpt == "raw" then
''
mv $rootDiskImage $out/${rootFilename}
''
else
''
${pkgs.qemu-utils}/bin/qemu-img convert -f raw -O ${formatOpt} ${compress} $rootDiskImage $out/${rootFilename}
''
}
rootDiskImage=$out/${rootFilename}
set -x
${postVM}
'';
}
''
export PATH=${binPath}
parted --script /dev/vda -- \
mklabel gpt \
mkpart ESP fat32 8MiB ${toString bootSize}MiB \
set 1 esp on \
align-check optimal 1 \
mkpart primary ${toString bootSize}MiB 100% \
align-check optimal 2 \
print
zpool create \
-o ashift=12 -o autotrim=on -o autoexpand=on \
-O acltype=posixacl -O atime=off -O compression=on \
-O mountpoint=none -O normalization=formD -O relatime=off \
-O xattr=sa -O canmount=off \
zroot /dev/vda2
zfs create zroot/local
zfs create zroot/local/var -o mountpoint=/var -u
zfs create zroot/local/nix -o mountpoint=legacy
mkdir -p /mnt/boot
mkfs.vfat -n ESP /dev/vda1
mount /dev/vda1 /mnt/boot
mkdir -p /mnt/nix
mount -t zfs zroot/local/nix /mnt/nix
export HOME=$TMPDIR
# Provide a Nix database so that nixos-install can copy closures.
export NIX_STATE_DIR=$TMPDIR/state
nix-store --load-db < ${closureInfo}/registration
chmod 755 $TMPDIR
nixos-install \
--root /mnt \
--no-root-passwd \
--system ${config.system.build.toplevel} \
--substituters ""
umount --recursive /mnt/boot
umount --recursive /mnt/nix
zpool export zroot
''
);
script = pkgs.writeShellScriptBin "runvm" ''
cp ${image}/nixos.root.qcow2 nixos.root.qcow2
${pkgs.qemu-utils}/bin/qemu-img resize nixos.root.qcow2 +10G
${pkgs.qemu}/bin/qemu-system-x86_64 \
-enable-kvm \
-m 4G \
-cpu host \
-bios ${pkgs.OVMF.fd}/FV/OVMF.fd \
-drive file=nixos.root.qcow2,format=qcow2,if=virtio \
-boot order=c
'';
in
script
|