Simple watchdog for local Tor Hidden Service

_hidden-service-watchdog.sh

#!/bin/bash
# fail early, be verbose
set -o errexit -o nounset -o xtrace
# confirm the service on port 22 is routable, bounce tor node if no success in 10 seconds
nc.openbsd -v -z -w 10 -x 127.0.0.1:9050 $(cat /var/lib/tor/hidden_service/hostname) 22 || (service tor restart; exit 1)

crontab

# run health check every hour (send email only on errors) 
42 * * * * chronic hidden-service-watchdog.sh