nixpkgs/pkgs/build-support/build-fhs-chrootenv/env.nix
Bjørn Forsman ad49db64da build-fhs-chrootenv: add /etc/mtab -> /proc/mounts symlink
Needed to be able to run some programs (e.g. tune2fs) in the chroot.

AFAIK, /etc/mtab is deprecated, but programs still use it.
2015-10-21 21:44:29 +02:00

193 lines
5.8 KiB
Nix

{ nixpkgs, nixpkgs_i686, system
} :
{ name, profile ? ""
, pkgs ? null, targetPkgs ? pkgs: [], multiPkgs ? pkgs: []
, extraBuildCommands ? "", extraBuildCommandsMulti ? ""
}:
# HOWTO:
# All packages (most likely programs) returned from targetPkgs will only be
# installed once--matching the host's architecture (64bit on x86_64 and 32bit on
# x86).
#
# Packages (most likely libraries) returned from multiPkgs are installed
# once on x86 systems and twice on x86_64 systems.
# On x86 they are merged with packages from targetPkgs.
# On x86_64 they are added to targetPkgs and in addition their 32bit
# versions are also installed. The final directory structure looks as
# follows:
# /lib32 will include 32bit libraries from multiPkgs
# /lib64 will include 64bit libraries from multiPkgs and targetPkgs
# /lib will link to /lib32
let
isMultiBuild = pkgs == null && multiPkgs != null && system == "x86_64-linux";
isTargetBuild = !isMultiBuild;
# support deprecated "pkgs" option.
targetPkgs' =
if pkgs != null
then builtins.trace "buildFHSEnv: 'pkgs' option is deprecated, use 'targetPkgs'" (pkgs': pkgs)
else targetPkgs;
# list of packages (usually programs) which are only be installed for the
# host's architecture
targetPaths = targetPkgs' nixpkgs ++ (if multiPkgs == null then [] else multiPkgs nixpkgs);
# list of packages which are installed for both x86 and x86_64 on x86_64
# systems
multiPaths = if isMultiBuild
then multiPkgs nixpkgs_i686
else [];
# base packages of the chroot
# these match the host's architecture, gcc/glibc_multi are used for multilib
# builds.
chosenGcc = if isMultiBuild then nixpkgs.gcc_multi else nixpkgs.gcc;
basePkgs = with nixpkgs;
[ (if isMultiBuild then glibc_multi else glibc)
chosenGcc
bashInteractive coreutils less shadow su
gawk diffutils findutils gnused gnugrep
gnutar gzip bzip2 xz glibcLocales
];
etcProfile = nixpkgs.writeText "profile" ''
export PS1='${name}-chrootenv:\u@\h:\w\$ '
export LOCALE_ARCHIVE='/usr/lib${if isMultiBuild then "64" else ""}/locale/locale-archive'
export LD_LIBRARY_PATH=/run/opengl-driver/lib:/run/opengl-driver-32/lib:/lib:/lib64
export PATH='/usr/bin:/usr/sbin'
${profile}
'';
# Compose /etc for the chroot environment
etcPkg = nixpkgs.stdenv.mkDerivation {
name = "${name}-chrootenv-etc";
buildCommand = ''
mkdir -p $out/etc
cd $out/etc
# environment variables
ln -s ${etcProfile} profile
# compatibility with NixOS
ln -s /host-etc/static static
# symlink some NSS stuff
ln -s /host-etc/passwd passwd
ln -s /host-etc/group group
ln -s /host-etc/shadow shadow
ln -s /host-etc/hosts hosts
ln -s /host-etc/resolv.conf resolv.conf
ln -s /host-etc/nsswitch.conf nsswitch.conf
# symlink other core stuff
ln -s /host-etc/localtime localtime
ln -s /host-etc/machine-id machine-id
ln -s /host-etc/os-release os-release
# symlink PAM stuff
ln -s /host-etc/pam.d pam.d
# symlink fonts stuff
ln -s /host-etc/fonts fonts
# symlink ALSA stuff
ln -s /host-etc/asound.conf asound.conf
# symlink SSL certs
mkdir -p ssl
ln -s /host-etc/ssl/certs ssl/certs
# symlink /etc/mtab -> /proc/mounts (compat for old userspace progs)
ln -s /proc/mounts mtab
'';
};
# Composes a /usr-like directory structure
staticUsrProfileTarget = nixpkgs.buildEnv {
name = "${name}-usr-target";
paths = [ etcPkg ] ++ basePkgs ++ targetPaths;
ignoreCollisions = true;
};
staticUsrProfileMulti = nixpkgs.buildEnv {
name = "system-profile-multi";
paths = multiPaths;
ignoreCollisions = true;
};
# setup library paths only for the targeted architecture
setupLibDirs_target = ''
mkdir -m0755 lib
# copy content of targetPaths
cp -rsHf ${staticUsrProfileTarget}/lib/* lib/
'';
# setup /lib, /lib32 and /lib64
setupLibDirs_multi = ''
mkdir -m0755 lib32
mkdir -m0755 lib64
ln -s lib32 lib
# copy glibc stuff
cp -rsHf ${staticUsrProfileTarget}/lib/32/* lib32/ && chmod u+w -R lib32/
# copy content of multiPaths (32bit libs)
[ -d ${staticUsrProfileMulti}/lib ] && cp -rsHf ${staticUsrProfileMulti}/lib/* lib32/ && chmod u+w -R lib32/
# copy content of targetPaths (64bit libs)
cp -rsHf ${staticUsrProfileTarget}/lib/* lib64/ && chmod u+w -R lib64/
# most 64bit only libs put their stuff into /lib
# some pkgs (like gcc_multi) put 32bit libs into /lib and 64bit libs into /lib64
# by overwriting these we will hopefully catch all these cases
# in the end /lib32 should only contain 32bit and /lib64 only 64bit libs
cp -rsHf ${staticUsrProfileTarget}/lib64/* lib64/ && chmod u+w -R lib64/
# copy gcc libs
cp -rsHf ${chosenGcc.cc}/lib/* lib32/
cp -rsHf ${chosenGcc.cc}/lib64/* lib64/
'';
setupLibDirs = if isTargetBuild then setupLibDirs_target
else setupLibDirs_multi;
# the target profile is the actual profile that will be used for the chroot
setupTargetProfile = ''
mkdir -m0755 usr
cd usr
${setupLibDirs}
for i in bin sbin share include; do
cp -r "${staticUsrProfileTarget}/$i" $i
done
cd ..
for i in var etc; do
cp -r "${staticUsrProfileTarget}/$i" "$i"
done
for i in usr/{bin,sbin,lib,lib32,lib64}; do
if [ -x "$i" ]; then
ln -s "$i"
fi
done
'';
in nixpkgs.stdenv.mkDerivation {
name = "${name}-fhs";
buildCommand = ''
mkdir -p $out
cd $out
${setupTargetProfile}
cd $out
${extraBuildCommands}
cd $out
${if isMultiBuild then extraBuildCommandsMulti else ""}
'';
preferLocalBuild = true;
passthru = {
pname = name;
};
}