mmdebstrap/tests/pivot_root

#!/bin/sh
set -eu
export LC_ALL=C.UTF-8
export SOURCE_DATE_EPOCH={{ SOURCE_DATE_EPOCH }}
trap "rm -f /tmp/chroot1.tar /tmp/chroot2.tar /tmp/chroot3.tar /tmp/mmdebstrap" EXIT INT TERM

prefix=
if [ "$(id -u)" -eq 0 ] && [ "{{ MODE }}" != "root" ] && [ "{{ MODE }}" != "auto" ]; then
  if ! id "${SUDO_USER:-user}" 2>/dev/null; then
    if [ ! -e /mmdebstrap-testenv ]; then
      echo "this test modifies the system and should only be run inside a container" >&2
      exit 1
    fi
    useradd --home-dir "/home/${SUDO_USER:-user}" --create-home "${SUDO_USER:-user}"
  fi
  prefix="runuser -u ${SUDO_USER:-user} --"
fi

$prefix {{ CMD }} --mode={{ MODE }} --variant=apt \
  --include=mount,perl \
  {{ DIST }} /tmp/chroot1.tar {{ MIRROR }}

if [ {{ MODE }} = "unshare" ]; then
  # calling pivot_root in root mode does not work for mysterious reasons:
  # pivot_root: failed to change root from `.' to `mnt': Invalid argument
  $prefix {{ CMD }} --mode={{ MODE }} --variant=apt --include=mount,perl \
    --customize-hook='mkdir -p "$1/mnt" "$1/oldroot"' \
    --customize-hook='[ ! -e /usr/bin/mmdebstrap ] || cp -aT /usr/bin/mmdebstrap "$1/usr/bin/mmdebstrap"' \
    --customize-hook='[ ! -e ./mmdebstrap ] || cp -aT ./mmdebstrap "$1/mnt/mmdebstrap"' \
    --customize-hook='mount -o rbind "$1" /mnt && cd /mnt && /sbin/pivot_root . oldroot' \
    --customize-hook='unshare -U echo nested unprivileged unshare' \
    --customize-hook='env --chdir=/mnt {{ CMD }} --mode=unshare --variant=apt --include=mount,perl {{ DIST }} /tmp/chroot3.tar {{ MIRROR }}' \
    --customize-hook='copy-out /tmp/chroot3.tar /tmp' \
    --customize-hook='rm -f "/usr/bin/mmdebstrap" "/mnt/mmdebstrap"' \
    --customize-hook='umount -l oldroot sys' \
    --customize-hook='rmdir /oldroot' \
    {{ DIST }} /tmp/chroot2.tar {{ MIRROR }}

  cmp /tmp/chroot1.tar /tmp/chroot2.tar || diffoscope /tmp/chroot1.tar /tmp/chroot2.tar
  cmp /tmp/chroot1.tar /tmp/chroot3.tar || diffoscope /tmp/chroot1.tar /tmp/chroot3.tar
  rm /tmp/chroot2.tar /tmp/chroot3.tar
fi

$prefix {{ CMD }} --mode={{ MODE }} --variant=apt --include=mount,perl \
  --customize-hook='mkdir -p "$1/mnt"' \
  --customize-hook='[ ! -e /usr/bin/mmdebstrap ] || cp -aT /usr/bin/mmdebstrap "$1/usr/bin/mmdebstrap"' \
  --customize-hook='[ ! -e ./mmdebstrap ] || cp -aT ./mmdebstrap "$1/mnt/mmdebstrap"' \
  --chrooted-customize-hook='env --chdir=/mnt {{ CMD }} --mode=unshare --variant=apt --include=mount,perl {{ DIST }} /tmp/chroot3.tar {{ MIRROR }}' \
  --customize-hook='copy-out /tmp/chroot3.tar /tmp' \
  --customize-hook='rm -f "$1/usr/bin/mmdebstrap" "$1/mnt/mmdebstrap"' \
  {{ DIST }} /tmp/chroot2.tar {{ MIRROR }}

cmp /tmp/chroot1.tar /tmp/chroot2.tar || diffoscope /tmp/chroot1.tar /tmp/chroot2.tar
cmp /tmp/chroot1.tar /tmp/chroot3.tar || diffoscope /tmp/chroot1.tar /tmp/chroot3.tar