#!/bin/bash
# from https://askubuntu.com/questions/3299/how-to-run-cron-job-when-network-is-up
# usage in root cron
##  @reboot bash /usr/share/customscripts/ifnet "/usr/share/customscripts/webhook bootup"

# Configurable values
## How many times we should check if we're online - this prevents infinite looping
MAX_CHECKS=10
## Seconds to sleep per loop
SLEEP_SECONDS=10
## error log
ERROR_LOG="/var/log/cron.error.log"
## any high availability host
HA_HOST="www.cloudflare.com"

# do da checcc
check_online () {
    # check if HA_HOST is reachable, echo 1 if online 0 if offline
    netcat -z -w 5 $HA_HOST 80 2>/dev/null && echo 1 || echo 0
}

# initial values
## Initial starting value for checks
CHECKS=1
## Initial check to see if we are online
IS_ONLINE=$(check_online)

# Loop while we're not online.
while [[ $IS_ONLINE -eq 0 ]]; do
    echo "$HA_HOST unreachable, loop $CHECKS/$MAX_CHECKS every $SLEEP_SECONDS seconds to run command \"$1\"" # only shows on manual run

    sleep $SLEEP_SECONDS # eepies

    IS_ONLINE=$(check_online) # recheck and update IS_ONLINE

    CHECKS=$(($CHECKS + 1))
    if [ $CHECKS -gt $MAX_CHECKS ]; then # if checks is over max, break loop
        break
    fi
done

# only reach this point after being checked in loop, check for 0 again for failure mode
if [[ $IS_ONLINE -eq 0 ]]; then
    # We never were able to get online. Kill script.
    sudo bash -c "echo \"$(date) | Failed to connect to $HA_HOST after $MAX_CHECKS attempts of $SLEEP_SECONDS seconds\" | tee -a $ERROR_LOG"
    exit
fi

sudo bash $1 2>> $ERROR_LOG # execute the bash script and log errors to the error log