hooks/merged-usr: implement post-merging as debootstrap does (see #1049898)

This commit is contained in:
Johannes Schauer Marin Rodrigues 2023-08-19 17:33:46 +02:00
parent 4d76d04cfe
commit 8d91ca7b24
Signed by untrusted user: josch
GPG key ID: F2CBA5C78FBD83E1
6 changed files with 115 additions and 36 deletions

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@ -26,7 +26,7 @@ esac
# 2. using ./hooks # 2. using ./hooks
# 3. using /usr/share/mmdebstrap/hooks/ # 3. using /usr/share/mmdebstrap/hooks/
for p in "$(dirname -- "$0")/.." ./hooks /usr/share/mmdebstrap/hooks; do for p in "$(dirname -- "$0")/.." ./hooks /usr/share/mmdebstrap/hooks; do
if [ -x "$p/merged-usr/setup00.sh" ] && [ -x "$p/merged-usr/essential00.sh" ]; then if [ -x "$p/merged-usr/setup00.sh" ] && [ -x "$p/merged-usr/extract00.sh" ] && [ -x "$p/merged-usr/essential00.sh" ]; then
"$p/merged-usr/essential00.sh" "$1" "$p/merged-usr/essential00.sh" "$1"
exit 0 exit 0
fi fi

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@ -0,0 +1,27 @@
#!/bin/sh
set -eu
env --chdir="$1" APT_CONFIG="$MMDEBSTRAP_APT_CONFIG" apt-get update --error-on=any
# if the usr-is-merged package cannot be installed with apt, do nothing
if ! env --chdir="$1" APT_CONFIG="$MMDEBSTRAP_APT_CONFIG" apt-cache show --no-all-versions usr-is-merged > /dev/null 2>&1; then
echo "no package called usr-is-merged found -- not running merged-usr extract hook" >&2
exit 0
else
echo "package usr-is-merged found -- running merged-usr extract hook" >&2
fi
# resolve the script path using several methods in order:
# 1. using dirname -- "$0"
# 2. using ./hooks
# 3. using /usr/share/mmdebstrap/hooks/
for p in "$(dirname -- "$0")/.." ./hooks /usr/share/mmdebstrap/hooks; do
if [ -x "$p/merged-usr/setup00.sh" ] && [ -x "$p/merged-usr/extract00.sh" ] && [ -x "$p/merged-usr/essential00.sh" ]; then
"$p/merged-usr/extract00.sh" "$1"
exit 0
fi
done
echo "cannot find merged-usr hook anywhere" >&2
exit 1

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@ -17,7 +17,7 @@ fi
# 2. using ./hooks # 2. using ./hooks
# 3. using /usr/share/mmdebstrap/hooks/ # 3. using /usr/share/mmdebstrap/hooks/
for p in "$(dirname -- "$0")/.." ./hooks /usr/share/mmdebstrap/hooks; do for p in "$(dirname -- "$0")/.." ./hooks /usr/share/mmdebstrap/hooks; do
if [ -x "$p/merged-usr/setup00.sh" ] && [ -x "$p/merged-usr/essential00.sh" ]; then if [ -x "$p/merged-usr/setup00.sh" ] && [ -x "$p/merged-usr/extract00.sh" ] && [ -x "$p/merged-usr/essential00.sh" ]; then
"$p/merged-usr/setup00.sh" "$1" "$p/merged-usr/setup00.sh" "$1"
exit 0 exit 0
fi fi

85
hooks/merged-usr/extract00.sh Executable file
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@ -0,0 +1,85 @@
#!/bin/sh
set -eu
if [ "${MMDEBSTRAP_VERBOSITY:-1}" -ge 3 ]; then
set -x
fi
TARGET="$1"
# can_usrmerge_symlink() and can_usrmerge_symlink() are
# Copyright 2023 Helmut Grohne <helmut@subdivi.de>
# and part of the debootstrap source in /usr/share/debootstrap/functions
# https://salsa.debian.org/installer-team/debootstrap/-/merge_requests/96
# https://bugs.debian.org/104989
can_usrmerge_symlink() {
# Absolute symlinks can be relocated without problems.
test "${2#/}" = "$2" || return 0
while :; do
if test "${2#/}" != "$2"; then
# Handle double-slashes.
set -- "$1" "${2#/}"
elif test "${2#./}" != "$2"; then
# Handle ./ inside a link target.
set -- "$1" "${2#./}"
elif test "$2" = ..; then
# A parent directory symlink is ok if it does not
# cross the top level directory.
test "${1%/*/*}" != "$1" -a -n "${1%/*/*}"
return $?
elif test "${2#../}" != "$2"; then
# Symbolic link crossing / cannot be moved safely.
# This is prohibited by Debian Policy 10.5.
test "${1%/*/*}" = "$1" -o -z "${1%/*/*}" && return 1
set -- "${1%/*}" "${2#../}"
else
# Consider the symlink ok if its target does not
# contain a parent directory. When we fail here,
# the link target is non-minimal and doesn't happen
# in the archive.
test "${2#*/../}" = "$2"
return $?
fi
done
}
merge_usr_entry() {
# shellcheck disable=SC3043
local entry canon
canon="$TARGET/usr/${1#"$TARGET/"}"
test -h "$canon" &&
error 1 USRMERGEFAIL "cannot move %s as its destination exists as a symlink" "${1#"$TARGET"}"
if ! test -e "$canon"; then
mv "$1" "$canon"
return 0
fi
test -d "$1" ||
error 1 USRMERGEFAIL "cannot move non-directory %s as its destination exists" "${1#"$TARGET"}"
test -d "$canon" ||
error 1 USRMERGEFAIL "cannot move directory %s as its destination is not a directory" "${1#"$TARGET"}"
for entry in "$1/"* "$1/."*; do
# Some shells return . and .. on dot globs.
test "${entry%/.}" != "${entry%/..}" && continue
if test -h "$entry" && ! can_usrmerge_symlink "${entry#"$TARGET"}" "$(readlink "$entry")"; then
error 1 USRMERGEFAIL "cannot move relative symlink crossing top-level directory" "${entry#"$TARGET"}"
fi
# Ignore glob match failures
if test "${entry%'/*'}" != "${entry%'/.*'}" && ! test -e "$entry"; then
continue
fi
merge_usr_entry "$entry"
done
rmdir "$1"
}
# This is list includes all possible multilib directories. It must be
# updated when new multilib directories are being added. Hopefully,
# all new architectures use multiarch instead, so we never get to
# update this.
for dir in bin lib lib32 lib64 libo32 libx32 sbin; do
test -h "$TARGET/$dir" && continue
test -e "$TARGET/$dir" || continue
merge_usr_entry "$TARGET/$dir"
ln -s "usr/$dir" "$TARGET/$dir"
done

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@ -47,40 +47,6 @@ fi
TARGET="$1" TARGET="$1"
ARCH=$(dpkg --print-architecture)
eval "$(APT_CONFIG="$MMDEBSTRAP_APT_CONFIG" apt-config shell ARCH Apt::Architecture)"
if [ -e /usr/share/debootstrap/functions ]; then
# shellcheck disable=SC1091
. /usr/share/debootstrap/functions
doing_variant () { [ "$1" != "buildd" ]; }
# shellcheck disable=SC2034
MERGED_USR="yes"
setup_merged_usr
else
link_dir=""
case $ARCH in
hurd-*) exit 0;;
amd64) link_dir="lib32 lib64 libx32" ;;
i386) link_dir="lib64 libx32" ;;
mips|mipsel) link_dir="lib32 lib64" ;;
mips64*|mipsn32*) link_dir="lib32 lib64 libo32" ;;
powerpc) link_dir="lib64" ;;
ppc64) link_dir="lib32 lib64" ;;
ppc64el) link_dir="lib64" ;;
s390x) link_dir="lib32" ;;
sparc) link_dir="lib64" ;;
sparc64) link_dir="lib32 lib64" ;;
x32) link_dir="lib32 lib64 libx32" ;;
esac
link_dir="bin sbin lib $link_dir"
for dir in $link_dir; do
ln -s usr/"$dir" "$TARGET/$dir"
mkdir -p "$TARGET/usr/$dir"
done
fi
# now install an empty "usr-is-merged" package to avoid installing the # now install an empty "usr-is-merged" package to avoid installing the
# usrmerge package on this system even after init-system-helpers starts # usrmerge package on this system even after init-system-helpers starts
# depending on "usrmerge | usr-is-merged". # depending on "usrmerge | usr-is-merged".

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@ -18,6 +18,7 @@ fi
TARGET="$1" TARGET="$1"
echo "Warning: starting with Debian 12 (Bookworm), systems without merged-/usr are not supported anymore" >&2 echo "Warning: starting with Debian 12 (Bookworm), systems without merged-/usr are not supported anymore" >&2
echo "Warning: starting with Debian 13 (Trixie), merged-/usr symlinks are shipped by packages in the essential-set making this hook ineffective" >&2
echo "this system will not be supported in the future" > "$TARGET/etc/unsupported-skip-usrmerge-conversion" echo "this system will not be supported in the future" > "$TARGET/etc/unsupported-skip-usrmerge-conversion"