Github Pages, Cloudflare Cache Purge

index.php

<?php

// Cloudflare settings
$CF_API_TOKEN = "";
$CF_ZONE = "";
$CF_EMAIL = "";

// API key
$AUTHORIZATION_KEY = "";

// API Log
$API_LOG = "output.log";

// Github hook ips
$AUTHORIZED_IPS = array(
    "204.232.175.64/27",
    "192.30.252.0/22",
);

// Sanity checks
if($AUTHORIZATION_KEY) {
    if(!array_key_exists('key', $_GET) ||
        $_GET['key'] !== $AUTHORIZATION_KEY) {
        die('Bad authorization key');
    }
}

// Purge function
function purge_url($url) {
    global $CF_API_TOKEN, $CF_ZONE, $CF_EMAIL;
    $payload = array(
        'a' => 'zone_file_purge',
        'tkn' => $CF_API_TOKEN,
        'email' => $CF_EMAIL,
        'z' => $CF_ZONE,
        'url' => $url,
    );

    $data = "";
    foreach($payload as $key => $val) {
        $data .= $key . '=' . urlencode($val) . '&';
    }
    rtrim($data, '&');

    $ch = curl_init();
    curl_setopt($ch,CURLOPT_URL, 'https://www.cloudflare.com/api_json.html');
    curl_setopt($ch,CURLOPT_POST, count($payload));
    curl_setopt($ch,CURLOPT_POSTFIELDS, $data);
    curl_setopt($ch,CURLOPT_RETURNTRANSFER, true);
    $result = curl_exec($ch);
    curl_close($ch);

    return $result;
}

if(count($AUTHORIZED_IPS) > 0) {
    if(!array_key_exists('REMOTE_ADDR', $_SERVER)) {
        die('Could not get IP');
    }

    $ip_match = False;
    foreach($AUTHORIZED_IPS as $range) {
        list($subnet, $mask) = explode('/', $range);

        $ip = ip2long($_SERVER['REMOTE_ADDR']);
        $subnet = ip2long($subnet);
        $mask = -1 << (32 - $mask);
        $subnet &= $mask;

        if(($ip & $mask) === $subnet) {
            $ip_match = True;
        }
    }

    if(!$ip_match) {
        die('Invalid IP');
    }
}

// Get the json
if(!array_key_exists('payload', $_REQUEST)) {
    die('No data passed');
}

$data = json_decode($_REQUEST['payload']);

if(!$data) {
    die('Could not decode JSON');
}

if($data->ref != "refs/heads/master") {
    die('Not on head');
}

if(!array_key_exists('commits', $data)) {
    die('Commits not found');
}

$modified_files = array();
foreach($data->commits as $commit) {
    $modified_files = array_merge($commit->added);
    $modified_files = array_merge($modified_files, $commit->modified);
    $modified_files = array_merge($modified_files, $commit->removed);
}

foreach($modified_files as $file) {
    $url = "http://" . $CF_ZONE . "/" . $file;
    $output = purge_url($url);

    $fh = fopen($API_LOG, 'a');
    fwrite($fh, "[" . date("d-m-Y H:i:s") . "] " . $output . "\n\n");
    fclose($fh);
}
die('ok');
?>