nixpkgs/pkgs/build-support/build-fhs-chrootenv/env.nix
Bjørn Forsman 05668fbe92 build-fhs-chrootenv: add /etc/os-release from host
This allows software inside the chroot to identify the host OS via the
standard /etc/os-release file.
2015-10-03 14:58:41 +02:00

224 lines
6.9 KiB
Nix

{ nixpkgs, nixpkgs_i686, system
} :
{ name, pkgs ? [], profile ? ""
, targetPkgs ? null, multiPkgs ? null
, extraBuildCommands ? "", extraBuildCommandsMulti ? ""
}:
assert pkgs != [] -> targetPkgs == null && multiPkgs == null;
assert targetPkgs != null -> multiPkgs != null;
assert multiPkgs != null -> targetPkgs != null;
assert targetPkgs != null -> pkgs == [];
# HOWTO:
# If pkgs is defined buildFHSEnv will run in legacy mode. This means
# it will build all pkgs contained in pkgs and basePkgs and then just merge
# all of their contents together via buildEnv.
#
# The new way is to define both targetPkgs and multiPkgs. These two are
# functions which get a pkgs environment supplied and should then return a list
# of packages based this environment.
# For example: targetPkgs = pkgs: [ pkgs.nmap ];
#
# All packages (most likely programs) placed in targetPkgs will only be
# installed once--matching the hosts architecture (64bit on x86_64 and 32bit on
# x86). These packages will populate the chroot directory tree.
#
# Packages (most likeley libraries) defined in multiPkgs will be installed once
# on x86 systems and twice on x86_64 systems.
# On x86 they will just be merge with the packages defined in targetPkgs.
# On x86_64 they will be added to targetPkgs and in addition their 32bit
# versions will also be installed. The final directory should look as follows:
# /lib will include 32bit libraries from multiPkgs
# /lib32 will link to /lib
# /lib64 will include 64bit libraries from multiPkgs and targetPkgs
# /x86 will contain a complete 32bit environment composed by multiPkgs
let
is64Bit = system == "x86_64-linux";
# enable multi builds on x86_64 hosts if pakgs_target/multi are defined
isMultiBuild = is64Bit && targetPkgs != null;
isTargetBuild = !isMultiBuild;
# list of packages (usually programs) which will only be installed for the
# hosts architecture
targetPaths = if targetPkgs == null
then pkgs
else targetPkgs nixpkgs ++ multiPkgs nixpkgs;
# list of pckages which should be build 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 hosts architecture, gcc/glibc_multi will be choosen
# on multi 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
];
# Compose /etc for the chroot environment
etcPkg = nixpkgs.stdenv.mkDerivation {
name = "${name}-chrootenv-etc";
buildCommand = ''
mkdir -p $out/etc
cd $out/etc
# environment variables
cat >> profile << "EOF"
export PS1='${name}-chrootenv:\u@\h:\w\$ '
export LOCALE_ARCHIVE='/usr/lib${if is64Bit then "64" else ""}/locale/locale-archive'
export LD_LIBRARY_PATH=/run/opengl-driver/lib:/run/opengl-driver-32/lib:/lib:/lib32:/lib64
export PATH='/bin:/sbin'
${profile}
EOF
# compatibility with NixOS
ln -s /host-etc/static static
# symlink some NSS stuff
ln -s /host-etc/passwd passwd
ln -s /host-etc/group group
ln -s /host-etc/shadow shadow
ln -s /host-etc/hosts hosts
ln -s /host-etc/resolv.conf resolv.conf
ln -s /host-etc/nsswitch.conf nsswitch.conf
# symlink other core stuff
ln -s /host-etc/localtime localtime
ln -s /host-etc/machine-id machine-id
ln -s /host-etc/os-release os-release
# symlink PAM stuff
ln -s /host-etc/pam.d pam.d
# symlink fonts stuff
ln -s /host-etc/fonts fonts
# symlink ALSA stuff
ln -s /host-etc/asound.conf asound.conf
# symlink SSL certs
mkdir -p ssl
ln -s /host-etc/ssl/certs ssl/certs
'';
};
# Composes a /usr like directory structure
staticUsrProfileTarget = nixpkgs.buildEnv {
name = "${name}-usr-target";
paths = [ etcPkg ] ++ basePkgs ++ targetPaths;
ignoreCollisions = true;
};
staticUsrProfileMulti = nixpkgs.buildEnv {
name = "system-profile-multi";
paths = multiPaths;
ignoreCollisions = true;
};
linkProfile = profile: ''
for i in ${profile}/{bin,sbin,share,var,etc}; do
if [ -x "$i" ]
then
ln -s "$i"
fi
done
'';
# this will happen on x86_64 host:
# /x86 -> links to the whole profile defined by multiPaths
# /lib, /lib32 -> links to 32bit binaries
# /lib64 -> links to 64bit binaries
# /usr/lib* -> same as above
setupMultiProfile = if isTargetBuild then "" else ''
mkdir -m0755 x86
cd x86
${linkProfile staticUsrProfileMulti}
cd ..
'';
# setup library paths only for the targeted architecture
setupLibDirs_target = ''
mkdir -m0755 lib
# copy content of targetPaths
cp -rsf ${staticUsrProfileTarget}/lib/* lib/
'';
# setup /lib, /lib32 and /lib64
setupLibDirs_multi = ''
mkdir -m0755 lib
mkdir -m0755 lib64
ln -s lib lib32
# copy glibc stuff
cp -rsf ${staticUsrProfileTarget}/lib/32/* lib/ && chmod u+w -R lib/
# copy content of multiPaths (32bit libs)
[ -d ${staticUsrProfileMulti}/lib ] && cp -rsf ${staticUsrProfileMulti}/lib/* lib/ && chmod u+w -R lib/
# copy content of targetPaths (64bit libs)
cp -rsf ${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 and /lib 64bit libs into /lib64
# by overwriting these we will hopefully catch all these cases
# in the end /lib should only contain 32bit and /lib64 only 64bit libs
cp -rsf ${staticUsrProfileTarget}/lib64/* lib64/ && chmod u+w -R lib64/
# copy gcc libs (and may overwrite exitsting wrongly placed libs)
cp -rsf ${chosenGcc.cc}/lib/* lib/
cp -rsf ${chosenGcc.cc}/lib64/* lib64/
'';
setupLibDirs = if isTargetBuild then setupLibDirs_target
else setupLibDirs_multi;
setupIncludeDir = ''
if [ -x "${staticUsrProfileTarget}/include" ]
then
ln -s "${staticUsrProfileTarget}/include"
fi
'';
# the target profile is the actual profile that will be used for the chroot
setupTargetProfile = ''
${linkProfile staticUsrProfileTarget}
${setupLibDirs}
mkdir -m0755 usr
cd usr
${linkProfile staticUsrProfileTarget}
${setupLibDirs}
${setupIncludeDir}
cd ..
rm -rf usr/etc usr/var
'';
in nixpkgs.stdenv.mkDerivation {
name = "${name}-fhs";
buildCommand = ''
mkdir -p $out
cd $out
${setupTargetProfile}
${setupMultiProfile}
cd $out
${extraBuildCommands}
cd $out
${if isMultiBuild then extraBuildCommandsMulti else ""}
'';
preferLocalBuild = true;
passthru = {
pname = name;
};
}