Guzzle 5 - get a URL with retries

guzzle_get_retry.php

<?php
/**
 * Get a URL, with automatic retries.
 *
 * @param \GuzzleHttp\Client $client
 * @param string             $url
 * @param int|float          $timeout
 * @param int                $max_attempts
 * 
 * @throws \GuzzleHttp\Exception\RequestException
 *   If there is an HTTP failure.
 * @throws \RuntimeException
 *   If there is an unexpected failure.
 *
 * @return \GuzzleHttp\Message\ResponseInterface
 *   The Guzzle HTTP response.
 */
function guzzle_get_retry(\GuzzleHttp\Client $client, $url, $timeout = 10, $max_attempts = 3) {
  for ($attempt = 0; $attempt < $max_attempts; $attempt++) {
    try {
      return $client->get($url, ['timeout' => $timeout]);
    }
    catch (\GuzzleHttp\Exception\RequestException $e) {
      // Abort immediately on 5xx errors.
      if ($e->hasResponse() && $e->getResponse()->getCode() >= 500) {
        throw $e;
      }
    }
  }
  throw isset($e) ? $e : new \RuntimeException('Request failed to URL: ' . $url);
}