chroot-enter.sh

#! /bin/bash -e

if ! [ -d "$1" ]; then
  echo "directory '$1' not exists" 1>&2
  exit 1
fi

if [ "x$2" == 'xstop' ]; then

  if mountpoint -q "$1/proc"; then
    echo "umount /proc"
    umount "$1/proc"
  fi

  if mountpoint -q "$1/sys"; then
    echo "umount /sys"
    umount "$1/sys"
  fi

  if mountpoint -q "$1/run"; then
    echo "umount /run"
    umount "$1/run"
  fi

  if mountpoint -q "$1/dev/mqueue"; then
    echo "umount /dev/mqueue"
    umount "$1/dev/mqueue"
  fi

  if mountpoint -q "$1/dev/shm"; then
    echo "umount /dev/shm"
    umount "$1/dev/shm"
  fi

  if mountpoint -q "$1/dev/pts"; then
    echo "umount /dev/pts"
    umount "$1/dev/pts"
  fi

  if mountpoint -q "$1/dev"; then
    echo "umount /dev"
    umount "$1/dev"
  fi

  if mountpoint -q "$1/usr/local/bin"; then
    echo "umount $1/usr/local/bin"
    umount "$1/usr/local/bin"
  fi

  if mountpoint -q "$1/tmp"; then
    echo "umount $1/tmp"
    umount "$1/tmp"
  fi

  if [[ -n "$SUDO_USER" ]] && mountpoint -q "$1/home/$SUDO_USER"; then
    echo "umount $1/home/$SUDO_USER"
    umount "$1/home/$SUDO_USER"
  fi

  echo "stopped"
  exit
fi

if ! [ -d "$1/proc" ]; then
  echo "directory '$1/proc' not exists" 1>&2
  exit 1
fi

if ! [ -d "$1/sys" ]; then
  echo "directory '$1/sys' not exists" 1>&2
  exit 1
fi

if ! [ -d "$1/dev" ]; then
  echo "directory '$1/dev' not exists" 1>&2
  exit 1
fi

if ! [ -d "$1/run" ]; then
  echo "directory '$1/run' not exists" 1>&2
  exit 1
fi

if ! mountpoint -q "$1/proc"; then
  echo "mount /proc"
  mount -t proc proc "$1/proc"
fi

if ! mountpoint -q "$1/sys"; then
  echo "mount /sys"
  mount -t sysfs sysfs "$1/sys"
fi

if ! mountpoint -q "$1/dev"; then
  echo "mount /dev"
  mount -t devtmpfs -o rw,nosuid,relatime,mode=755 devtmpfs "$1/dev"
fi

if ! mountpoint -q "$1/dev/pts"; then
  echo "mount /dev/pts"
  mount -t devpts -o rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 devpts "$1/dev/pts"
fi

if ! mountpoint -q "$1/dev/shm"; then
  echo "mount /dev/shm"
  mount -t tmpfs -o rw,nosuid,nodev tmpfs "$1/dev/shm"
fi

#if ! [ -d "$1/dev/mqueue" ]; then
#  echo "mkdir $1/dev/mqueue"
#  mkdir "$1/dev/mqueue"
#fi

if ! mountpoint -q "$1/dev/mqueue"; then
  echo "mount /dev/mqueue"
  mount -t mqueue -o rw,relatime mqueue "$1/dev/mqueue"
fi

if ! mountpoint -q "$1/run"; then
  echo "mount /run"
  mount -t tmpfs -o rw,nosuid,noexec,relatime,size=87504k,mode=755 tmpfs "$1/run"
fi

if [[ -d "$1/usr/local/bin" ]] && [[ -d /usr/local/bin ]] && ! mountpoint -q "$1/usr/local/bin"; then
  echo "mount /usr/local/bin"
  mount --bind /usr/local/bin "$1/usr/local/bin"
fi

if ! mountpoint -q "$1/tmp"; then
  echo "mount /tmp"
  mount --bind /tmp "$1/tmp"
fi

if [[ -n "$SUDO_USER" ]] && [[ -d "$1/home/$SUDO_USER" ]] && [[ -d "/home/$SUDO_USER" ]] && ! mountpoint -q "$1/home/$SUDO_USER"; then
  echo "mount /home/$SUDO_USER"
  mount --bind "/home/$SUDO_USER" "$1/home/$SUDO_USER"
fi

chroot $@