nixpkgs/pkgs/build-support/singularity-tools/default.nix
2017-12-21 10:50:06 +11:00

104 lines
2.7 KiB
Nix

{ runCommand
, stdenv
, storeDir ? builtins.storeDir
, writeScript
, singularity
, writeReferencesToFile
, bash
, vmTools
, gawk
, utillinux
, e2fsprogs
, squashfsTools }:
rec {
shellScript = name: text:
writeScript name ''
#!${stdenv.shell}
set -e
${text}
'';
mkLayer = {
name,
contents ? [],
}:
runCommand "singularity-layer-${name}" {
inherit contents;
} ''
mkdir $out
for f in $contents ; do
cp -ra $f $out/
done
'';
buildImage = {
name,
contents ? [],
diskSize ? 1024,
runScript ? "#!${stdenv.shell}\nexec /bin/sh",
runAsRoot ? null,
extraSpace ? 0
}:
let layer = mkLayer {
inherit name;
contents = contents ++ [ bash runScriptFile ];
};
runAsRootFile = shellScript "run-as-root.sh" runAsRoot;
runScriptFile = shellScript "run-script.sh" runScript;
result = vmTools.runInLinuxVM (
runCommand "singularity-image-${name}.img" {
buildInputs = [ singularity e2fsprogs utillinux gawk ];
layerClosure = writeReferencesToFile layer;
preVM = vmTools.createEmptyImage {
size = diskSize;
fullName = "singularity-run-disk";
};
}
''
rm -rf $out
mkdir disk
mkfs -t ext3 -b 4096 /dev/${vmTools.hd}
mount /dev/${vmTools.hd} disk
cd disk
mkdir proc sys dev
# Run root script
${stdenv.lib.optionalString (runAsRoot != null) ''
mkdir -p ./${storeDir}
mount --rbind ${storeDir} ./${storeDir}
unshare -imnpuf --mount-proc chroot ./ ${runAsRootFile}
umount -R ./${storeDir}
''}
# Build /bin and copy across closure
mkdir -p bin nix/store
for f in $(cat $layerClosure) ; do
cp -ar $f ./$f
for f in $f/bin/* ; do
if [ ! -e bin/$(basename $f) ] ; then
ln -s $f bin/
fi
done
done
# Create runScript
ln -s ${runScriptFile} singularity
# Size calculation
cd ..
umount disk
size=$(resize2fs -P /dev/${vmTools.hd} | awk '{print $NF}')
mount /dev/${vmTools.hd} disk
cd disk
export PATH=$PATH:${e2fsprogs}/bin/
echo creating
singularity image.create -s $((1 + size * 4 / 1024 + ${toString extraSpace})) $out
echo importing
tar -c . | singularity image.import $out
'');
in result;
}