tomato-on-demand-services.sh

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

#          name: tomato-on-demand-services.sh
#       version: 1.0.1, 25-jun-2020, by eibgrad
#       purpose: auto start/stop service(s) on-demand
#   script type: init (autostart)
#  installation:
#    1. enable jffs (administration->jffs)
#    2. enable syslog (administration->logging->syslog)
#    3. use shell (telnet/ssh) to execute one of the following commands:
#         curl -kLs bit.ly/tomato-installer|tr -d '\r'|sh -s -- N3Uc9TC0 init
#       or
#         wget -qO - bit.ly/tomato-installer|tr -d '\r'|sh -s -- N3Uc9TC0 init
#    4. modify script w/ your preferred options:
#         vi /jffs/etc/config/tomato-on-demand-services.init
#    5. reboot
(
# ------------------------------ BEGIN OPTIONS ------------------------------- #

# device(s) to be monitored (fqdn or ip, space-separated)
DEVICES='mikes-iphone'

# service(s) to be managed (based on process name, space-separated)
SERVICES='vpnserver1 vpnserver2'

# interval between checks
INTERVAL=60

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

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

_ping() { ping -qc1 -w10 "$1" >/dev/null 2>&1; }

_echo() { echo "$* @ $(date)"; }

[[ "$DEVICES" && "$SERVICES" ]] || { echo 'nothing to do... exiting'; exit 0; }

# wait for internet access
while ! _ping 8.8.8.8; do sleep 10; done

while :; do
    ping_success=true

    for dev in $DEVICES; do
        for i in 1 2 3; do
            _ping $dev && continue 2
        done

        ping_success=false; break
    done

    # if all pings succeed, stop service(s)
    # if at least one ping fails, start service(s)

    if [[ $ping_success == true ]]; then
        for svc in $SERVICES; do
            if pidof $svc >/dev/null 2>&1; then
                service $svc stop >/dev/null 2>&1
                _echo "$svc - stopped"
            else
                [ ${DEBUG+x} ] && _echo "$svc - nothing to do"
            fi
        done
    else
        for svc in $SERVICES; do
            if ! pidof $svc >/dev/null 2>&1; then
                service $svc start >/dev/null 2>&1
                _echo "$svc - started"
            else
                [ ${DEBUG+x} ] && _echo "$svc - nothing to do"
            fi
        done
    fi

    sleep $INTERVAL
done

) 2>&1 | logger $([ ${DEBUG+x} ] && echo "-p user.debug") \
    -t $(echo $(basename $0) | grep -Eo '^.{0,23}')[$$] &