my_lxc-destroy

#!/bin/bash
#
# lxc-destroy wrapper by Roberto Puzzanghera https://notes.sagredo.eu
#
# Usage: my_lxc-destroy <container_name>
#

. /usr/local/bin/my_lxc-common

NAME=$1

# Container name must be provided
if [ -z "$NAME" ]; then
  echo "Container name is required."
  echo "Usage: $0 <container_name>"
  exit 1
fi

del_user() {
  /bin/egrep  -q -i "^${1}:" /etc/passwd
  if [ $? -eq 0 ]; then
    echo "Deleting $1..."
    pkill -u $1
    userdel $1
    if [ $? -ne 0 ]; then
      echo "userdel failed in removing user $1."
      exit 1
    fi
    # remove home, as the top dir is owned by root
    if [ -d /home/$1 ]; then
      rm -rf /home/$1
    fi
    # remove maildir
    if [ -e /var/spool/mail/$1 ]; then
      rm /var/spool/mail/$1
    fi
  else
    echo "User $1 does not exists in /etc/passwd. Exiting..."
    exit 1
  fi
}

remove_ids() {
  START_UID=$(sed -n "/#/! s/^${NAME}:\(.*\):.*/\1/p" /etc/subuid)
    END_UID=$(sed -n "/#/! s/^${NAME}:.*:\(.*\)/\1/p" /etc/subuid)
    END_UID=$(($END_UID + $START_UID))

  START_GID=$(sed -n "/#/! s/^${NAME}:\(.*\):.*/\1/p" /etc/subgid)
    END_GID=$(sed -n "/#/! s/^${NAME}:.*:\(.*\)/\1/p" /etc/subgid)
    END_GID=$(($END_GID + $START_GID))

  usermod --del-subuids $START_UID-$END_UID $NAME
  usermod --del-subgids $START_GID-$END_GID $NAME
}

delete_user() {
  # unload cgroup
  cgclear -l /etc/cgconfig.d/$1.conf
  if [ $? -ne 0 ]; then
    echo "cgclear failed in unloading cgroups. Check later..."
  fi
  # remove cgconfig/cgrules config files
  rm /etc/cgconfig.d/$1.conf
  rm /etc/cgrules.d/$1.conf

  # remove user from lxc-usernet
  sed -i "/${1} /d" /etc/lxc/lxc-usernet
  if [ $? -ne 0 ]; then
    echo "Failed in removing user $1 from usernet. Exiting..."
    exit 1
  fi

  # is it safe to delete the user?
  echo -n "User ${1} is going to be deleted. Be sure that it is not a system wide user like apache, mysql etc. "
  echo -n "Confirm [y/n]? [n] "
  read USER_DELETE
  if [ "$USER_DELETE" != 'y' ] && [ "$USER_DELETE" != 'Y' ]; then
    echo "Ok. User $1 won't be deleted."
  else
    del_user $1
    if [ $? -ne 0 ]; then
      echo "Failed in deleting user $1. Exiting..."
      exit 1
    fi
  fi
}

destroy() {
  # Destroy it!
  lxc-destroy $1
  if [ $? -ne 0 ]; then
    echo "Failed in destroying container $1. Exiting..."
    exit 1
  fi
}

########################################################################################

# sanity check
if [ ! -n "$1" ]; then
  echo
  echo "Missing container name."
  echo "Usage: $0 <name>"
  echo
  exit 1
fi

container_exists $NAME
if [ $? -eq 0 ]; then
  echo "Container $NAME does not exist. Exiting..."
  exit 1
fi

# is it safe to destroy the container?
echo -n "${NAME} container is going to be destroyed. Confirm [y/n]? [n] "
read NAME_DESTROY
if [ "$NAME_DESTROY" != 'y' ] && [ "$NAME_DESTROY" != 'Y' ]; then
  echo "Exiting."
  exit 0
fi

# find the owner of $NAME container
USER=$(owner $NAME)
if [ $? -ne 0 ]; then
  echo "Failed in retrieving the owner of the container $NAME. Exiting..."
  exit 1
fi

# stop the container
stop_container $NAME $USER
if [ $? -ne 0 ]; then
  echo "Failed in stopping container $NAME. Exiting..."
  exit 1
fi

# check if it's root. If yes destroy and do not procede to user delete tasks.
if [ "$USER" = 'root' ]; then
  lxc-destroy $NAME
  exit 1
fi

# check if $USER is the owner of any other container. If yes do not delete that user
i=0;
for CONTAIN in $(/usr/bin/lxc-ls); do
  # is it unprivileged?
  if grep -q 'lxc.idmap' $LXC_PATH/$CONTAIN/config; then
    # find owner of the container (NB: no spaces around the '=')
    USER2=$(owner $CONTAIN)
    if [ "$USER2" = "$USER" ] && [ "$CONTAIN" != "$NAME" ]; then
      ((i++))
      if [ $i -eq 1 ];then
        echo "User $USER is owner of some other container. We won't delete it."
      fi
    fi
  fi
done

if [ $i -eq 0 ]; then
  # Delete user
  delete_user $USER
  if [ $? -ne 0 ]; then
    echo "Failed in deleting user $USER. Exiting..."
    exit 1
  fi
fi

# Destroy it!
echo "Destroying $NAME container..."
lxc-destroy $NAME
if [ $? -ne 0 ]; then
  echo "Failed in destroying container ${NAME}. Exiting..."
  exit 1
else
  echo "...done."
  exit 0
fi