nixpkgs/nixos/lib/make-iso9660-image.nix
K900 77536af43b nixos/iso-image: extremely cursed performance optimization for Hydra
Right now the worst case chain of events for building an ISO on Hydra is

    - copy everything to squashfs builder
    - run squashfs builder
    - download squashfs from builder
    - compress squashfs
    - upload squashfs to S3
    - copy squashfs to ISO builder
    - run ISO builder
    - download ISO from builder
    - compress ISO
    - upload ISO to S3

This inlines the squashfs build into the ISO build, which makes it

    - copy everything to ISO builder
    - run ISO builder
    - download ISO from builder
    - compress ISO
    - upload ISO to S3

Which should reduce queue runner load by $alot per ISO, which we have four of on small channels
(one release, one test per arch) and a lot more than four of on large channels (with various desktops)
2024-03-12 15:41:59 +03:00

87 lines
2.9 KiB
Nix

{ lib, stdenv, callPackage, closureInfo, xorriso, syslinux, libossp_uuid, squashfsTools
, # The file name of the resulting ISO image.
isoName ? "cd.iso"
, # The files and directories to be placed in the ISO 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
, # In addition to `contents', the closure of the store paths listed
# in `storeContents' are also placed in the Nix store of the CD.
# This is a list of attribute sets {object, symlink} where `object'
# is a store path whose closure will be copied, and `symlink' is a
# symlink to `object' that will be added to the CD.
storeContents ? []
, # In addition to `contents', the closure of the store paths listed
# in `squashfsContents' is compressed as squashfs and the result is
# placed in /nix-store.squashfs on the CD.
# FIXME: This is a performance optimization to avoid Hydra copying
# the squashfs between builders and should be removed when Hydra
# is smarter about scheduling.
squashfsContents ? []
, # Compression settings for squashfs
squashfsCompression ? "xz -Xdict-size 100%"
, # Whether this should be an El-Torito bootable CD.
bootable ? false
, # Whether this should be an efi-bootable El-Torito CD.
efiBootable ? false
, # Whether this should be an hybrid CD (bootable from USB as well as CD).
usbBootable ? false
, # The path (in the ISO file system) of the boot image.
bootImage ? ""
, # The path (in the ISO file system) of the efi boot image.
efiBootImage ? ""
, # The path (outside the ISO file system) of the isohybrid-mbr image.
isohybridMbrImage ? ""
, # Whether to compress the resulting ISO image with zstd.
compressImage ? false, zstd
, # The volume ID.
volumeID ? ""
}:
assert bootable -> bootImage != "";
assert efiBootable -> efiBootImage != "";
assert usbBootable -> isohybridMbrImage != "";
let
needSquashfs = squashfsContents != [];
makeSquashfsDrv = callPackage ./make-squashfs.nix {
storeContents = squashfsContents;
comp = squashfsCompression;
};
in
stdenv.mkDerivation {
name = isoName;
__structuredAttrs = true;
buildCommandPath = ./make-iso9660-image.sh;
nativeBuildInputs = [ xorriso syslinux zstd libossp_uuid ]
++ lib.optionals needSquashfs makeSquashfsDrv.nativeBuildInputs;
inherit isoName bootable bootImage compressImage volumeID efiBootImage efiBootable isohybridMbrImage usbBootable;
sources = map (x: x.source) contents;
targets = map (x: x.target) contents;
objects = map (x: x.object) storeContents;
symlinks = map (x: x.symlink) storeContents;
squashfsCommand = lib.optionalString needSquashfs makeSquashfsDrv.buildCommand;
# For obtaining the closure of `storeContents'.
closureInfo = closureInfo { rootPaths = map (x: x.object) storeContents; };
}