Monitor an Endpoint on Telegram

ping.php

<?php

// Config information
$server = "IP/DOMAINWHOTOMONITOR"; // the address to test, without the "http://"
$port = "PORT";

// Telegram Bot API configuration
$telegramToken = 'YOURTELEGRAMTOKEN';
$chatId = 'YOURTELEGRAMCHATID';

// Create a text file to store the result of the ping for comparison
$db = "pingdata.txt";

if (file_exists($db)) {
    $previous_status = file_get_contents($db, true);
} else {
    file_put_contents($db, "up");
    $previous_status = "up";
}

// Ping the server and check if it's up
$current_status = ping($server, $port, 10);

// If it's down, log it and send alert
if ($current_status == "down") {
    echo "Server is down! ";
    file_put_contents($db, "down");

    if ($previous_status == "up") {
        sendTelegramMessage("Server is down!");
        echo "Alert sent.";
    }

} else {
    echo "Server is up! ";
    file_put_contents($db, "up");

    if ($previous_status == "down") {
        sendTelegramMessage("Server is back up!");
        echo "Alert sent.";
    }
}

function ping($host, $port, $timeout)
{
    $tB = microtime(true);
    $fP = fsockopen($host, $port, $errno, $errstr, $timeout);
    if (!$fP) {
        return "down";
    }
    $tA = microtime(true);
    return round((($tA - $tB) * 1000), 0) . " ms";
}

function sendTelegramMessage($message)
{
    global $telegramToken, $chatId;
    $telegramUrl = "https://api.telegram.org/bot" . $telegramToken . "/sendMessage";
    $telegramParams = [
        "chat_id" => $chatId,
        "text" => $message,
    ];
    $ch = curl_init($telegramUrl);
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($telegramParams));
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    $result = curl_exec($ch);
    curl_close($ch);
}