nixpkgs/nixos/lib/make-squashfs.nix
2018-01-09 11:25:19 -05:00

57 lines
1.7 KiB
Nix

{ stdenv, squashfsTools, perl, pathsFromGraph
, # The root directory of the squashfs filesystem is filled with the
# closures of the Nix store paths listed here.
storeContents ? []
}:
stdenv.mkDerivation {
name = "squashfs.img";
nativeBuildInputs = [perl squashfsTools];
# For obtaining the closure of `storeContents'.
exportReferencesGraph =
map (x: [("closure-" + baseNameOf x) x]) storeContents;
buildCommand =
''
# Add the closures of the top-level store objects.
storePaths=$(perl ${pathsFromGraph} closure-*)
# If a Hydra slave happens to have store paths with bad permissions/mtime,
# abort now so that they don't end up in ISO images in the channel.
# https://github.com/NixOS/nixpkgs/issues/32242
hasBadPaths=""
for path in $storePaths; do
if [ -h "$path" ]; then
continue
fi
mtime=$(stat -c %Y "$path")
mode=$(stat -c %a "$path")
if [ "$mtime" != 1 ]; then
echo "Store path '$path' has an invalid mtime."
hasBadPaths=1
fi
if [ "$mode" != 444 ] && [ "$mode" != 555 ]; then
echo "Store path '$path' has invalid permissions ($mode)."
hasBadPaths=1
fi
done
if [ -n "$hasBadPaths" ]; then
echo "You have bad paths in your store, please fix them."
exit 1
fi
# Also include a manifest of the closures in a format suitable
# for nix-store --load-db.
printRegistration=1 perl ${pathsFromGraph} closure-* > nix-path-registration
# Generate the squashfs image.
mksquashfs nix-path-registration $storePaths $out \
-keep-as-directory -all-root -b 1048576 -comp xz -Xdict-size 100%
'';
}