tomato-ovpn-server-watchdog.sh

#!/bin/sh
#DEBUG=; set -x # uncomment/comment to enable/disable debug mode

#          name: tomato-ovpn-server-watchdog.sh
#       version: 1.0.0, 07-oct-2024, by eibgrad
#       purpose: (re)start failed/stopped openvpn server(s)
#   script type: init (autostart)
#  installation:
#    1. enable jffs (administration->jffs)
#    2. enable syslog (status->logs->logging configuration->syslog)
#    3. enable 'enable on start' option for openvpn server(s) to be monitored
#    4. use shell (telnet/ssh) to execute one of the following commands:
#         curl -kLs bit.ly/tomato-installer|tr -d '\r'|sh -s -- tbQ1yAR0 init
#       or
#         wget -qO - bit.ly/tomato-installer|tr -d '\r'|sh -s -- tbQ1yAR0 init
#    5. (optional) use vi editor to modify options:
#         vi /jffs/etc/config/tomato-ovpn-server-watchdog.init
#    6. reboot
(
# ------------------------------ BEGIN OPTIONS ------------------------------- #

# participating openvpn server(s) [ '1 2'=only | '*'=all | ''=none ]
PARTICIPANTS='*'

# time (in secs) between checks for failed/stopped openvpn server(s)
CHECK_INTERVAL=60

# ------------------------------- END OPTIONS -------------------------------- #

# ---------------------- DO NOT CHANGE BELOW THIS LINE ----------------------- #

LOCK="/tmp/$(basename $0).lock"

# reject additional instances
mkdir $LOCK &>/dev/null || exit 0

# catch unexpected exit and cleanup
trap "rmdir $LOCK; exit 0" SIGHUP SIGINT SIGTERM

# wait for *reliable* internet connection
until ping -qc1 -W3 8.8.8.8 &>/dev/null; do sleep 10; done

while sleep $CHECK_INTERVAL; do
    # process all "enable on start" openvpn servers
    for i in $(nvram get vpn_server_eas | tr ',' ' '); do
        # confirm openvpn server is participant
        echo "$PARTICIPANTS" | grep -q "[*$i]" || continue

        pidof vpnserver${i} &>/dev/null && continue

        # fall-through means failure; restart the openvpn server
        service vpnserver${i} restart >/dev/null && sleep 5
        echo "info: openvpn server #$i (re)started @ $(date)"
    done
done

) 2>&1 | logger -t "$(basename $0 | grep -Eo '^.{0,23}')[$$]" &