The problem usually happens because the mysql password is not correctly set.  I have ran into the issue even at times when there was no mysql password.
 Solution 1: set a password
1. $ mysqladmin -u root password NEWPASSWORD or $ mysqladmin -u root -p'oldpassword' password newpass
2. set a mysql password edit: /var/www/fog/commons/config.php and /opt/fog/service/etc/config.php
 
Solution 2:  Add corrected values to /service config.
1. vi /opt/fog/service/etc/config.php
2. add host:"localhost" username:"root" database:"fog"