Getting SAML to play nice with Memcached for PHP 7.1 [#2912807]

I am trying to get an existing site upgraded to PHP 7.1 from 5.6 on Acquia. I needed to update the memcache module to the latest version (2.0-alpha4) as part of the process. In the documentation (https://docs.acquia.com/acquia-cloud/known-issues) it mentioned that memcache would be deprecated for 7. I'm currently using the SAML library 1.14.16 and am getting this error:

php-error staging-19842 [29-Sep-2017 10:40:15 America/Chicago] Uncaught PHP Exception Exception: "Missing Memcache class. Is the memcache extension installed?" at /.../.../.../.../vendor/simplesamlphp/simplesamlphp/lib/SimpleSAML/Memcache.php line 297 request_id="v-84e8d976-a52c-11e7-afe5-063f2feb7b10"

Any help would be greatly appreciated.

Comments

Comment #1

29 September 2017 at 15:41

kkambeya created an issue. See original summary.

Comment #2

yojohnyo commented 11 October 2017 at 19:56

We encountered this same problem. As a workaround we switched from using memcache to store session information to use the database.

Comment #3

kkambeya commented 12 October 2017 at 17:08

Using the database isn't an option for this project. I was able to do a workaround. Here's what I did:

1) Add the commits from https://github.com/simplesamlphp/simplesamlphp/pull/395/files/5880a72f2f...

2) Change lines 296-301 of simplesamlphp/lib/SimpleSAML/Memcache.php to:

if (!class_exists('Memcached')) {
throw new Exception('Missing Memcache class. Is the memcache extension installed?');
}

// create the Memcache object
$memcache = new Memcached();

FROM

if (!class_exists('Memcache')) {
throw new Exception('Missing Memcache class. Is the memcache extension installed?');
}

// create the Memcache object
$memcache = new Memcache();

I'm not sure if its the best approach but it does work. Which makes me believe the issue is not with the module.

Comment #4

camoa commented 25 October 2017 at 15:30

Checking on this issue:

PHP 7.1 has deprecated the php-memcache module in favor of the php-memcached, this causes the simplesamlphp library to crash on any release of version 1.14.

This issue was fixed for SimpleSAMLPHP v. 1.15(any of the RC) but this brought another issue:

in the SImpleSAMLPHPAuthManager.php file we have this:

  /**
   * {@inheritdoc}
   *
   * @param ConfigFactoryInterface $config_factory
   *   The configuration factory.
   * @param SimpleSAML_Auth_Simple $instance
   *   SimpleSAML_Auth_Simple instance.
   * @param SimpleSAML_Configuration $config
   *   SimpleSAML_Configuration instance.
   */
  public function __construct(ConfigFactoryInterface $config_factory, SimpleSAML_Auth_Simple $instance = NULL, SimpleSAML_Configuration $config = NULL) {
    $this->checkLibrary();
    $this->config = $config_factory->get('simplesamlphp_auth.settings');
    if (!$instance) {
      $auth_source = $this->config->get('auth_source');
     <strong> $this->instance = new SimpleSAML_Auth_Simple($auth_source);</strong>
    }
    else {
      $this->instance = $instance;
    }

    if (!$config) {
      $this->simplesamlConfig = \SimpleSAML_Configuration::getInstance();
    }
    else {
      $this->simplesamlConfig = $config;
    }
  }

Problem is V1.15 of the library renamed this class to Simple and this is causing issues now on the Drupal side.