Drush was not able to start (bootstrap) the Drupal database.

drush dl disqus
[notice] Project disqus (8.x-1.0-rc1) downloaded to /opt/lampp/htdocs/website//modules/disqus.
drush en disqus
[error] Command pm-enable needs a higher bootstrap level to run - you will need to invoke drush from a more functional Drupal environment to run this command.
[error] The drush command 'en disqus' could not be executed.
[error] Drush was not able to start (bootstrap) the Drupal database.
Hint: This may occur when Drush is trying to:
* bootstrap a site that has not been installed or does not have a configured database. In this case you can select another site with a working database setup by specifying the URI to use with the --uri parameter on the command line. See `drush topic docs-aliases` for details.
* connect the database through a socket. The socket file may be wrong or the php-cli may have no access to it in a jailed shell. See http://drupal.org/node/1428638 for details.

Drush was attempting to connect to:
Drupal version : 8.1.3
Site URI : http://default
Database driver : mysql
Database hostname : localhost
Database port : 3306
Database username : root
Database name : website
PHP configuration : /etc/php/php.ini
PHP OS : Linux
Drush script : /usr/share/webapps/drush/drush.phar
Drush version : 9.0-dev
Drush temp directory : /tmp
Drush configuration :
Drush alias files : /etc/drush/aliases.drushrc.php
Drupal root : /opt/lampp/htdocs/website
Drupal Settings File : sites/default/settings.php
Site path : sites/default
Sync config path : sites/default/files/config_0zmvrOOK_1FYrvFphuxQwHH9zoW8Owkih_fBfP2q2DefAJn1x2IyC2lFI2CWr0o5GxT
7whTc1g/sync