post_install() {
  # create group and user
  if ! getent group radicale &>/dev/null; then
    groupadd -r radicale >/dev/null
  fi
  if ! getent passwd radicale &>/dev/null; then
    useradd -r -c "Radicale user" -d /var/empty -g adm -s /bin/nologin radicale >/dev/null
  fi
}

post_upgrade() {
  # configuration and file system storage changes with >= 3.0.0
  if [ "$(vercmp "$2" "3.0.0")" -le 0 ]; then
    echo "WARNING: Major changes introduced to filesystem storage and configuration. Read /usr/share/doc/radicale/NEWS.md"
  fi
}

post_remove() {
  if getent passwd radicale &>/dev/null; then
    userdel radicale >/dev/null
  fi
  if getent group radicale &>/dev/null; then
    groupdel radicale >/dev/null
  fi
}