Retrieves IP of server and sends it to user via Slack. Used when a server boots up.

ip-to-slack.js

<?php

$slackWebhookUrl = "https://hooks.slack.com/services/this/comes/from/slack/after/setting/up/a/webhook";
$slackChannel = 'molly';

// Keeps trying to get the IP address for 20 times
$retries = 0;
$ipAddress = null;
while(empty($ipAddress) && $retries < 20) {
  $ipAddress = exec("ip addr | grep 'state UP' -A2 | tail -n1 | awk '{print $2}' | cut -f1  -d'/'");

  if(empty($ipAddress)) {
    usleep(100000); //sleep for 100ms
  }
  $retries++;
}

$dataString = json_encode(array(
  "payload" => array(
    'channel' => 'molly',
    'text' => 'The IP of this server is: ' . $ipAddress,
    'username' => 'ipbot'
    )
  ));

//open connection
$ch = curl_init();

//set the url, number of POST vars, POST data
curl_setopt($ch, CURLOPT_URL, $slackWebhookUrl);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, $fields_string);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(                                                                          
    'Content-Type: application/json',                                                                                
    'Content-Length: ' . strlen($dataString))                                                                       
);

//execute post
$result = curl_exec($ch);

//close connection
curl_close($ch);