linuxShortcuts/Services/fixDNS.sh

function isDNSWorking() {
    dnsWorking=$(dig brunofontes.net | grep "ANSWER: 0")
}
logfile="/var/log/bfontes"

sudo echo "$(date +"%Y-%m-%d %H:%M:%S") - Checking if DNS is working" >> "$logfile"
isDNSWorking

if [ "$dnsWorking" ]; then
    sudo echo "$(date +"%Y-%m-%d %H:%M:%S") - DNS not working, hour may be wrong. Trying to fix..." >> "$logfile"
    sudo chattr -i /etc/resolv.conf
    sudo sed -i 's/127.0.0.2/9.9.9.9/' /etc/resolv.conf 2>>"$logfile"
    sudo chattr +i /etc/resolv.conf

    sudo echo "$(date +"%Y-%m-%d %H:%M:%S") - Forcing time to sync" >> "$logfile"
    sudo chronyc online 2>"$logfile"
    sudo chronyc -a 'burst 4/4'
    i=0
    while [ "$dnsWorking" -a $i -le 4 ]; do
        sudo echo "$(date +"%Y-%m-%d %H:%M:%S") - Waiting..." >> "$logfile"
        sleep 20
        isDNSWorking
        i=$(( "$i" + 1 ))
    done

    if [ -z "$dnsWorking" ]; then
        sudo echo "$(date +"%Y-%m-%d %H:%M:%S") - FIXED!" >> "$logfile"
    else
        sudo echo "$(date +"%Y-%m-%d %H:%M:%S") - Script has failed..." >> "$logfile"
        sudo echo "$(date +"%Y-%m-%d %H:%M:%S") - Fixing DNS script has failed. More details on $logfile" >> ~/.log_error
    fi
    sudo echo "$(date +"%Y-%m-%d %H:%M:%S") - Configuring DNS servers back." >> "$logfile"
    sudo chattr -i /etc/resolv.conf
    sudo sed -i 's/9.9.9.9/127.0.0.2/' /etc/resolv.conf
    sudo chattr +i /etc/resolv.conf
fi
sudo echo "$(date +"%Y-%m-%d %H:%M:%S") - Done" >> "$logfile"