A small script to grab floating IP's from Digital Ocean and check if they still have DNS entries pointing at them using Bing's ip: search

do-ip-fisher.php

#!/usr/local/bin/php
<?php

//////////////////////////////////////////////////////
//   A quick POC to grab IP's from Digital Ocean    //
//   that still have DNS records pointing to them   //
//                                                  //
//        Config: 1. Set BING_API_KEY               //
//                2. Set DO_API_KEY                 //
//                                                  //
//danclifford.eu                                    //
//////////////////////////////////////////////////////

define('BING_API_KEY', 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXX');
define('BING_API_URL', 'https://api.datamarket.azure.com/Bing/Search/Web?$format=json&Query=');    
define('DO_API_KEY','XXXXXXXXXXXXXXXXXXXXXXXXXXXXX');

//The current (at time of writing) list of regions floating IP's are available from
$do_region_array = array(
                    "AMS2",
                    "AMS3",
                    "FRA1",
                    "LON1",
                    "NYC1",
                    "NYC2",
                    "NYC3",
                    "SFO1",
                    "SGP1",
                    "TOR1"
);

//Minimal function to interact with the Digital Ocean API
function doAPI($url, $action, $droplet_id = null)
{
    $ch = curl_init();
    
    $headers = array(
        "Authorization: Bearer " . DO_API_KEY,
        "Content-Type: application/json"
    );
    
    if (isset($droplet_id)) {
        $post_data = array(
            "region" => $droplet_id,
        );
        
        $post_data_json = json_encode($post_data);        
        $headers[] = "Content-Length: " . strlen($post_data_json);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $post_data_json);
    } else {
        curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "DELETE");
    }
    
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_URL, $url . $action);
    curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
    curl_setopt($ch, CURLOPT_CAINFO, 'cacert.pem');
    
    $response = curl_exec($ch);

    if ($response === false) {
        print("Error accessing Digital Ocean: " .curl_error($ch));
        return 1;    
    }

    return $response;
}

//Minimal function to interact with the Bing API
function bingReverseIP($ip_address)
{
    $headers = array(
        'Authorization: Basic ' . base64_encode(BING_API_KEY . ":" . BING_API_KEY)
    );
        
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_URL, BING_API_URL . '%27ip%3a' . $ip_address . '%27');
    curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
    curl_setopt($ch, CURLOPT_CAINFO, 'cacert.pem');
    $response = curl_exec($ch);

    return(json_decode($response));
}

while (1) {
    foreach ($do_region_array as $region) {
        $assign_ip = doAPI("https://api.digitalocean.com/v2/", "floating_ips", $region);
        $request_response = json_decode($assign_ip);
        
        if ($request_response !== 1) {        
            $fresh_ip = $request_response->floating_ip->ip;
            print "Grabbed IP: " . $fresh_ip;
            $bing_ip_search = bingReverseIP($fresh_ip);
            
            //If no bing ip: records are found, release the IP and continue
            //If bing ip: records are found, count the results, list them and retain the IP
            if (empty($bing_ip_search->d->results)) {
                print " no records found\n";
                sleep(30); //Give time to grab the IP 
                doAPI("https://api.digitalocean.com/v2/", "floating_ips/" . $fresh_ip);
                print "Released IP: " . $fresh_ip . "\n";
            }else{
                print " matched " . count($bing_ip_search->d->results) . " hosts\n";
                print "Hosts:\n";
                $found_hosts = listBingResults($bing_ip_search);
                foreach ($found_hosts->d->results as $host) {
                    print $host->Url . "\n";
                };
                print "Keeping IP: " . $fresh_ip . "\n";
            }
        }
        
        sleep(30); 

    }
}