restart nginx if ttyd is down

check_ttyd

#!/bin/bash
# restart nginx if ttyd is down
# add to Unraid User Scripts plugin as script named "check_ttyd"
# run every 5 minutes: */5 * * * *
# latest version: https://gist.github.com/ljm42/294968bcecb5308bbcd1c75ae693c680
PROG="check_ttyd user script"
EVENT="Unraid Server Notice"
DESC="Notification from ${PROG}"
TMP=/tmp/check_ttyd

log() {
  logger "${PROG}-$1"
  echo "`date` ${PROG}-$1"
  echo "`date` ${PROG}-$1" >> $TMP
}

# try to access the webterminal
curl --head --max-time 3 http://localhost/webterminal/ &>/dev/null
if [ "$?" -ne "0" ]
then
  if [ -e ${TMP} ]
  then
    # hmm, nginx was restarted during the last run and there is still a problem. don't do anything.
    log "ttyd is still down, not restarted"
    exit 1
  fi
  # restart nginx to restart ttyd
  /etc/rc.d/rc.nginx restart
  if [ "$?" -eq "0" ]
  then
    SEV="warning"
    MSG="ttyd down, nginx restarted"
    log "${MSG}"
    /usr/local/emhttp/webGui/scripts/notify -e "${EVENT}" -s "${MSG}" -d "${DESC}" -i "${SEV}"
    exit 0
  else
    SEV="alert"
    MSG="ttyd down, unable to restart nginx"
    log "${MSG}"
    /usr/local/emhttp/webGui/scripts/notify -e "${EVENT}" -s "${MSG}" -d "${DESC}" -i "${SEV}"
    exit 1
  fi
else
  echo "everything is fine"
  # if the tmp file exists, delete it
  if [ -e ${TMP} ]
  then
    rm ${TMP}
  fi
  exit 0
fi