nixpkgs/pkgs/build-support/build-fhsenv-bubblewrap/default.nix
Thomas Watson dd99084843 buildFHSEnvBubblewrap: allow more varied $DISPLAY syntax
The $DISPLAY variable has a format of [host]:num[.screen]. Previously,
the number would only be extracted properly if it had the form :num.
Allow all forms but correctly discard the unused parts.
2024-05-16 10:14:07 -05:00

291 lines
8.5 KiB
Nix

{ lib
, stdenv
, callPackage
, runCommandLocal
, writeShellScript
, glibc
, pkgsi686Linux
, coreutils
, bubblewrap
}:
{ runScript ? "bash"
, extraInstallCommands ? ""
, meta ? {}
, passthru ? {}
, extraPreBwrapCmds ? ""
, extraBwrapArgs ? []
, unshareUser ? false
, unshareIpc ? false
, unsharePid ? false
, unshareNet ? false
, unshareUts ? false
, unshareCgroup ? false
, privateTmp ? false
, dieWithParent ? true
, ...
} @ args:
assert (!args ? pname || !args ? version) -> (args ? name); # You must provide name if pname or version (preferred) is missing.
let
inherit (lib)
concatLines
concatStringsSep
escapeShellArgs
filter
optionalString
splitString
;
inherit (lib.attrsets) removeAttrs;
name = args.name or "${args.pname}-${args.version}";
executableName = args.pname or args.name;
# we don't know which have been supplied, and want to avoid defaulting missing attrs to null. Passed into runCommandLocal
nameAttrs = lib.filterAttrs (key: value: builtins.elem key [ "name" "pname" "version" ]) args;
buildFHSEnv = callPackage ./buildFHSEnv.nix { };
fhsenv = buildFHSEnv (removeAttrs args [
"runScript" "extraInstallCommands" "meta" "passthru" "extraPreBwrapCmds" "extraBwrapArgs" "dieWithParent"
"unshareUser" "unshareCgroup" "unshareUts" "unshareNet" "unsharePid" "unshareIpc" "privateTmp"
]);
etcBindEntries = let
files = [
# NixOS Compatibility
"static"
"nix" # mainly for nixUnstable users, but also for access to nix/netrc
# Shells
"shells"
"bashrc"
"zshenv"
"zshrc"
"zinputrc"
"zprofile"
# Users, Groups, NSS
"passwd"
"group"
"shadow"
"hosts"
"resolv.conf"
"nsswitch.conf"
# User profiles
"profiles"
# Sudo & Su
"login.defs"
"sudoers"
"sudoers.d"
# Time
"localtime"
"zoneinfo"
# Other Core Stuff
"machine-id"
"os-release"
# PAM
"pam.d"
# Fonts
"fonts"
# ALSA
"alsa"
"asound.conf"
# SSL
"ssl/certs"
"ca-certificates"
"pki"
];
in map (path: "/etc/${path}") files;
# Create this on the fly instead of linking from /nix
# The container might have to modify it and re-run ldconfig if there are
# issues running some binary with LD_LIBRARY_PATH
createLdConfCache = ''
cat > /etc/ld.so.conf <<EOF
/lib
/lib/x86_64-linux-gnu
/lib64
/usr/lib
/usr/lib/x86_64-linux-gnu
/usr/lib64
/lib/i386-linux-gnu
/lib32
/usr/lib/i386-linux-gnu
/usr/lib32
/run/opengl-driver/lib
/run/opengl-driver-32/lib
EOF
ldconfig &> /dev/null
'';
init = run: writeShellScript "${name}-init" ''
source /etc/profile
${createLdConfCache}
exec ${run} "$@"
'';
indentLines = str: concatLines (map (s: " " + s) (filter (s: s != "") (splitString "\n" str)));
bwrapCmd = { initArgs ? "" }: ''
${extraPreBwrapCmds}
ignored=(/nix /dev /proc /etc ${optionalString privateTmp "/tmp"})
ro_mounts=()
symlinks=()
etc_ignored=()
# loop through all entries of root in the fhs environment, except its /etc.
for i in ${fhsenv}/*; do
path="/''${i##*/}"
if [[ $path == '/etc' ]]; then
:
elif [[ -L $i ]]; then
symlinks+=(--symlink "$(${coreutils}/bin/readlink "$i")" "$path")
ignored+=("$path")
else
ro_mounts+=(--ro-bind "$i" "$path")
ignored+=("$path")
fi
done
# loop through the entries of /etc in the fhs environment.
if [[ -d ${fhsenv}/etc ]]; then
for i in ${fhsenv}/etc/*; do
path="/''${i##*/}"
# NOTE: we're binding /etc/fonts and /etc/ssl/certs from the host so we
# don't want to override it with a path from the FHS environment.
if [[ $path == '/fonts' || $path == '/ssl' ]]; then
continue
fi
if [[ -L $i ]]; then
symlinks+=(--symlink "$i" "/etc$path")
else
ro_mounts+=(--ro-bind "$i" "/etc$path")
fi
etc_ignored+=("/etc$path")
done
fi
# propagate /etc from the actual host if nested
if [[ -e /.host-etc ]]; then
ro_mounts+=(--ro-bind /.host-etc /.host-etc)
else
ro_mounts+=(--ro-bind /etc /.host-etc)
fi
# link selected etc entries from the actual root
for i in ${escapeShellArgs etcBindEntries}; do
if [[ "''${etc_ignored[@]}" =~ "$i" ]]; then
continue
fi
if [[ -e $i ]]; then
symlinks+=(--symlink "/.host-etc/''${i#/etc/}" "$i")
fi
done
declare -a auto_mounts
# loop through all directories in the root
for dir in /*; do
# if it is a directory and it is not ignored
if [[ -d "$dir" ]] && [[ ! "''${ignored[@]}" =~ "$dir" ]]; then
# add it to the mount list
auto_mounts+=(--bind "$dir" "$dir")
fi
done
declare -a x11_args
# Always mount a tmpfs on /tmp/.X11-unix
# Rationale: https://github.com/flatpak/flatpak/blob/be2de97e862e5ca223da40a895e54e7bf24dbfb9/common/flatpak-run.c#L277
x11_args+=(--tmpfs /tmp/.X11-unix)
# Try to guess X socket path. This doesn't cover _everything_, but it covers some things.
if [[ "$DISPLAY" == *:* ]]; then
# recover display number from $DISPLAY formatted [host]:num[.screen]
display_nr=''${DISPLAY/#*:} # strip host
display_nr=''${display_nr/%.*} # strip screen
local_socket=/tmp/.X11-unix/X$display_nr
x11_args+=(--ro-bind-try "$local_socket" "$local_socket")
fi
${optionalString privateTmp ''
# sddm places XAUTHORITY in /tmp
if [[ "$XAUTHORITY" == /tmp/* ]]; then
x11_args+=(--ro-bind-try "$XAUTHORITY" "$XAUTHORITY")
fi
# dbus-run-session puts the socket in /tmp
IFS=";" read -ra addrs <<<"$DBUS_SESSION_BUS_ADDRESS"
for addr in "''${addrs[@]}"; do
[[ "$addr" == unix:* ]] || continue
IFS="," read -ra parts <<<"''${addr#unix:}"
for part in "''${parts[@]}"; do
printf -v part '%s' "''${part//\\/\\\\}"
printf -v part '%b' "''${part//%/\\x}"
[[ "$part" == path=/tmp/* ]] || continue
x11_args+=(--ro-bind-try "''${part#path=}" "''${part#path=}")
done
done
''}
cmd=(
${bubblewrap}/bin/bwrap
--dev-bind /dev /dev
--proc /proc
--chdir "$(pwd)"
${optionalString unshareUser "--unshare-user"}
${optionalString unshareIpc "--unshare-ipc"}
${optionalString unsharePid "--unshare-pid"}
${optionalString unshareNet "--unshare-net"}
${optionalString unshareUts "--unshare-uts"}
${optionalString unshareCgroup "--unshare-cgroup"}
${optionalString dieWithParent "--die-with-parent"}
--ro-bind /nix /nix
${optionalString privateTmp "--tmpfs /tmp"}
# Our glibc will look for the cache in its own path in `/nix/store`.
# As such, we need a cache to exist there, because pressure-vessel
# depends on the existence of an ld cache. However, adding one
# globally proved to be a bad idea (see #100655), the solution we
# settled on being mounting one via bwrap.
# Also, the cache needs to go to both 32 and 64 bit glibcs, for games
# of both architectures to work.
--tmpfs ${glibc}/etc \
--tmpfs /etc \
--symlink /etc/ld.so.conf ${glibc}/etc/ld.so.conf \
--symlink /etc/ld.so.cache ${glibc}/etc/ld.so.cache \
--ro-bind ${glibc}/etc/rpc ${glibc}/etc/rpc \
--remount-ro ${glibc}/etc \
'' + optionalString fhsenv.isMultiBuild (indentLines ''
--tmpfs ${pkgsi686Linux.glibc}/etc \
--symlink /etc/ld.so.conf ${pkgsi686Linux.glibc}/etc/ld.so.conf \
--symlink /etc/ld.so.cache ${pkgsi686Linux.glibc}/etc/ld.so.cache \
--ro-bind ${pkgsi686Linux.glibc}/etc/rpc ${pkgsi686Linux.glibc}/etc/rpc \
--remount-ro ${pkgsi686Linux.glibc}/etc \
'') + ''
"''${ro_mounts[@]}"
"''${symlinks[@]}"
"''${auto_mounts[@]}"
"''${x11_args[@]}"
${concatStringsSep "\n " extraBwrapArgs}
${init runScript} ${initArgs}
)
exec "''${cmd[@]}"
'';
bin = writeShellScript "${name}-bwrap" (bwrapCmd { initArgs = ''"$@"''; });
in runCommandLocal name (nameAttrs // {
inherit meta;
passthru = passthru // {
env = runCommandLocal "${name}-shell-env" {
shellHook = bwrapCmd {};
} ''
echo >&2 ""
echo >&2 "*** User chroot 'env' attributes are intended for interactive nix-shell sessions, not for building! ***"
echo >&2 ""
exit 1
'';
inherit args fhsenv;
};
}) ''
mkdir -p $out/bin
ln -s ${bin} $out/bin/${executableName}
${extraInstallCommands}
''