Guzzle, allow_redirects and cookies are in a boat...

gistfile1.php

<?php

$httpClient = new \GuzzleHttp\Client;

$response = $httpClient->post('http://foo.bar', [ 'body' => [ 'username' => 'mageekguy', 'password' => 'A very strong password, isn\' it?', ], 'allow_redirects' => false, 'cookies' => true ]);

echo '<pre>';
var_dump($response->getStatusCode(), $response->getHeaders());
echo '</pre>';
/*
int(302)
array(5) {
  ["Date"]=>
  array(1) {
    [0]=>
    string(29) "Mon, 16 Feb 2015 09:21:11 GMT"
  }
  ["Server"]=>
  array(1) {
    [0]=>
    string(6) "Apache"
  }
  ["Location"]=>
  array(1) {
    [0]=>
    string(15) "admin/index.php"
  }
  ["Content-Length"]=>
  array(1) {
    [0]=>
    string(1) "0"
  }
  ["Content-Type"]=>
  array(1) {
    [0]=>
    string(11) "'text/html'"
  }
}
*/

$response = $httpClient->post('http://foo.bar', [ 'body' => [ 'username' => 'mageekguy', 'password' => 'A very strong password, isn\' it?', ], 'allow_redirects' => true, 'cookies' => true ]);

echo '<pre>';
var_dump($response->getStatusCode(), $response->getHeaders());
echo '</pre>';
/*
int(200)
array(6) {
  ["Date"]=>
  array(1) {
    [0]=>
    string(29) "Mon, 16 Feb 2015 09:22:38 GMT"
  }
  ["Server"]=>
  array(1) {
    [0]=>
    string(6) "Apache"
  }
  ["P3P"]=>
  array(1) {
    [0]=>
    string(28) "CP="CUR ADM OUR NOR STA NID""
  }
  ["Set-Cookie"]=>
  array(1) {
    [0]=>
    string(74) "sessionID=phpads54e1b6de2d4bf6-59183461; path=/; domain=fh.v1.adaccess.dev"
  }
  ["Transfer-Encoding"]=>
  array(1) {
    [0]=>
    string(7) "chunked"
  }
  ["Content-Type"]=>
  array(1) {
    [0]=>
    string(29) "text/html; charset=ISO-8859-1"
  }
}
*/