Purpose of this directory to store SimplesamlPHP configuration.

SimplesamlPHP library code manages via composer and stored in vendor/simplesamlphp

Configuration from this directory attached to application via vhost settings in apache server like:

  SetEnv SIMPLESAMLPHP_CONFIG_DIR /var/www/html/simplesamlphp/config
  Alias /simplesaml /var/www/vendor/simplesamlphp/simplesamlphp/www

In example above is assumes that your project installed in /var/www directory.

Recommended directories configuration in simplesamlphp/config/config.php file:

    'certdir' => '/project/root/path/simplesamlphp/cert/',
    'loggingdir' => '/project/root/path/logs/simplesamlphp/',
    'datadir' => '/project/root/path/simplesamlphp/data/',
    'tempdir' => '/project/root/path/tmp/simplesamlphp',

Configuration from this directory attached to application via vhost settings in apache server like:

  SetEnv SIMPLESAMLPHP_CONFIG_DIR /var/simplesamlphp/config
  Alias /simplesaml /var/simplesamlphp/www

Add extra line to [docroot]/sites/default/settings.php

$settings['simplesamlphp_dir'] = '/var/simplesamlphp';