solar_collector/scripts/check_vpn.sh

#!/bin/sh

# Configuration
LOG_FILE="/var/log/vpn_check.log"
VPN_SERVICE="vpnc@fb"
ROUTER_IP="192.168.178.1"
VPN_CHECK_URL="https://tbsgl.xyz/vpn"
RESTART_CHECK_URL="https://tbsgl.xyz/restart"

# Log function
log() {
    now=$(date)
    echo "${now} - $1" | tee -a ${LOG_FILE}
}

# Check URL function
check_url() {
    curl -sI $1 | grep "HTTP/2 200" > /dev/null
    return $?
}

# Check VPN Connectivity
check_vpn_connectivity() {
    ping -c 1 ${ROUTER_IP} | grep "64 bytes from" > /dev/null
    if [ $? != 0 ]; then
        systemctl restart ${VPN_SERVICE} > /dev/null
        log "Ping not successful - Restarting VPN"
    else
        log "Ping reached router, doing nothing"
    fi
}

# Main
log "Running Check"

# Check if VPN-On Flag is set
if check_url ${VPN_CHECK_URL}; then
    check_vpn_connectivity
else
    systemctl stop ${VPN_SERVICE}
    log "VPN Flag seems to be disabled or no Internet, stopping service"
fi

# Additional Functionality: Check for Restart Condition
if check_url ${RESTART_CHECK_URL}; then
    log "Restart condition met - Restarting device"
    reboot now
fi