nixpkgs/nixos/lib/make-disk-image.nix
Bjørn Forsman 0ff4bb5f87 nixos: run parted with --script option
-s, --script: never prompts for user intervention

Sometimes the NixOS installer tests fail when they invoke parted, e.g.
https://hydra.nixos.org/build/62513826/nixlog/1. But instead of exiting
right there, the tests hang until the Nix builder times out (and kills
the build). With this change the tests would instead fail immediately,
which is preferred.

While at it, use "parted --script" treewide, so nobody gets build
timeout due to parted error (or misuse). (Only nixos/ use it, and only
non-interactive.)

A few instances already use the short option "-s", convert them to long
option "--short".
2017-10-14 15:29:02 +02:00

192 lines
5.7 KiB
Nix

{ pkgs
, lib
, # The NixOS configuration to be installed onto the disk image.
config
, # The size of the disk, in megabytes.
diskSize
# The files and directories to be placed in the target file system.
# This is a list of attribute sets {source, target} where `source'
# is the file system object (regular file or directory) to be
# grafted in the file system at path `target'.
, contents ? []
, # Whether the disk should be partitioned (with a single partition
# containing the root filesystem) or contain the root filesystem
# directly.
partitioned ? true
# Whether to invoke switch-to-configuration boot during image creation
, installBootLoader ? true
, # The root file system type.
fsType ? "ext4"
, # The initial NixOS configuration file to be copied to
# /etc/nixos/configuration.nix.
configFile ? null
, # Shell code executed after the VM has finished.
postVM ? ""
, name ? "nixos-disk-image"
, format ? "raw"
}:
with lib;
let
extensions = {
qcow2 = "qcow2";
vpc = "vhd";
raw = "img";
};
nixpkgs = lib.cleanSource pkgs.path;
channelSources = pkgs.runCommand "nixos-${config.system.nixosVersion}" {} ''
mkdir -p $out
cp -prd ${nixpkgs} $out/nixos
chmod -R u+w $out/nixos
if [ ! -e $out/nixos/nixpkgs ]; then
ln -s . $out/nixos/nixpkgs
fi
rm -rf $out/nixos/.git
echo -n ${config.system.nixosVersionSuffix} > $out/nixos/.version-suffix
'';
metaClosure = pkgs.writeText "meta" ''
${config.system.build.toplevel}
${config.nix.package.out}
${channelSources}
'';
prepareImageInputs = with pkgs; [ rsync utillinux parted e2fsprogs lkl fakeroot config.system.build.nixos-prepare-root ] ++ stdenv.initialPath;
# I'm preserving the line below because I'm going to search for it across nixpkgs to consolidate
# image building logic. The comment right below this now appears in 4 different places in nixpkgs :)
# !!! should use XML.
sources = map (x: x.source) contents;
targets = map (x: x.target) contents;
prepareImage = ''
export PATH=${pkgs.lib.makeSearchPathOutput "bin" "bin" prepareImageInputs}
mkdir $out
diskImage=nixos.raw
truncate -s ${toString diskSize}M $diskImage
${if partitioned then ''
parted --script $diskImage -- mklabel msdos mkpart primary ext4 1M -1s
offset=$((2048*512))
'' else ''
offset=0
''}
mkfs.${fsType} -F -L nixos -E offset=$offset $diskImage
root="$PWD/root"
mkdir -p $root
# Copy arbitrary other files into the image
# Semi-shamelessly copied from make-etc.sh. I (@copumpkin) shall factor this stuff out as part of
# https://github.com/NixOS/nixpkgs/issues/23052.
set -f
sources_=(${concatStringsSep " " sources})
targets_=(${concatStringsSep " " targets})
set +f
for ((i = 0; i < ''${#targets_[@]}; i++)); do
source="''${sources_[$i]}"
target="''${targets_[$i]}"
if [[ "$source" =~ '*' ]]; then
# If the source name contains '*', perform globbing.
mkdir -p $root/$target
for fn in $source; do
rsync -a --no-o --no-g "$fn" $root/$target/
done
else
mkdir -p $root/$(dirname $target)
if ! [ -e $root/$target ]; then
rsync -a --no-o --no-g $source $root/$target
else
echo "duplicate entry $target -> $source"
exit 1
fi
fi
done
# TODO: Nix really likes to chown things it creates to its current user...
fakeroot nixos-prepare-root $root ${channelSources} ${config.system.build.toplevel} closure
echo "copying staging root to image..."
cptofs ${pkgs.lib.optionalString partitioned "-P 1"} -t ${fsType} -i $diskImage $root/* /
'';
in pkgs.vmTools.runInLinuxVM (
pkgs.runCommand name
{ preVM = prepareImage;
buildInputs = with pkgs; [ utillinux e2fsprogs ];
exportReferencesGraph = [ "closure" metaClosure ];
postVM = ''
${if format == "raw" then ''
mv $diskImage $out/nixos.img
diskImage=$out/nixos.img
'' else ''
${pkgs.qemu}/bin/qemu-img convert -f raw -O ${format} $diskImage $out/nixos.${extensions.${format}}
diskImage=$out/nixos.${extensions.${format}}
''}
${postVM}
'';
memSize = 1024;
}
''
${if partitioned then ''
. /sys/class/block/vda1/uevent
mknod /dev/vda1 b $MAJOR $MINOR
rootDisk=/dev/vda1
'' else ''
rootDisk=/dev/vda
''}
# Some tools assume these exist
ln -s vda /dev/xvda
ln -s vda /dev/sda
mountPoint=/mnt
mkdir $mountPoint
mount $rootDisk $mountPoint
# Install a configuration.nix
mkdir -p /mnt/etc/nixos
${optionalString (configFile != null) ''
cp ${configFile} /mnt/etc/nixos/configuration.nix
''}
mount --rbind /dev $mountPoint/dev
mount --rbind /proc $mountPoint/proc
mount --rbind /sys $mountPoint/sys
# Set up core system link, GRUB, etc.
NIXOS_INSTALL_BOOTLOADER=1 chroot $mountPoint /nix/var/nix/profiles/system/bin/switch-to-configuration boot
# TODO: figure out if I should activate, but for now I won't
# chroot $mountPoint /nix/var/nix/profiles/system/activate
# The above scripts will generate a random machine-id and we don't want to bake a single ID into all our images
rm -f $mountPoint/etc/machine-id
umount -R /mnt
# Make sure resize2fs works. Note that resize2fs has stricter criteria for resizing than a normal
# mount, so the `-c 0` and `-i 0` don't affect it. Setting it to `now` doesn't produce deterministic
# output, of course, but we can fix that when/if we start making images deterministic.
${optionalString (fsType == "ext4") ''
tune2fs -T now -c 0 -i 0 $rootDisk
''}
''
)