#your ip at : myhostname.mydomain es: my.mydns.com

#domain
$mydomain = "yourdomain.com"
#Production on godaddy https://developer.godaddy.com/keys
$myhostname = "my"
#pubkey:privatekey
$gdapikey = "9Q7p8YLDzVg_MCggBvJXYBCPRsKCP3KzSL:5KDtXPfgRxQH2uD9pa1HBW"

#log
$logfile = "log.txt"
Add-Content $($logfile) 'starting deamon..'

$myip = Invoke-RestMethod -Uri "https://api.ipify.org"
$dnsdata = Invoke-RestMethod -Uri "https://api.godaddy.com/v1/domains/$($mydomain)/records/A/$($myhostname)" -Headers @{ Authorization = "sso-key $($gdapikey)" }
$gdip = $dnsdata.data

#clear log if it's too long
$nlines = 0;
# Read file by 1000 lines at a time
gc $logfile -read 1000 | % { $nlines += $_.Length };
[string]::Format("{0} has {1} lines", $logfile, $nlines)
if ($nlines -gt 2000){
    Clear-Content $($logfile)
    Add-Content $($logfile) 'Log cleared.'
}

#log and output
$log1 = "$(Get-Date -Format 'u') - Current External IP is $($myip), GoDaddy DNS IP is $($gdip)"
Add-Content $($logfile) $log1
Write-Output $log1

if ( $gdip -NotMatch $myip ) {

   Invoke-RestMethod -Method PUT -Uri "https://api.godaddy.com/v1/domains/$($mydomain)/records/A/$($myhostname)" -Headers @{ Authorization = "sso-key $($gdapikey)" } -ContentType "application/json" -Body "[{`"data`": `"$($myip)`"}]";

   Add-Content $($logfile) "IP has changed!! Updating on GoDaddy from $($gdip) to new: $($myip) "
   Write-Output "IP has changed!! Updating on GoDaddy"

}else
{
   Add-Content $($logfile) 'No updates to do!'
   Write-Output "No updates to do!"
}