Working with BOA ( Barracuda / Octopus / Aegir ) , I've installed a few Drupal sites without any problems and following the same process for all.
BOA is running on Nginx. All sites are going thru Cloudflare's network , where I set the same DNS settings.
A example.com points to IPADDRESS
A www points to IPADDRESS
the nameservers of each domain are pointing to Cloudflare's respective nameservers.
It all works , except for one site that works perfectly without "www" , but with "www" returns the typical database error if Drupal can't find the site's database.
The site is currently not available due to technical problems. Please try again later. Thank you for your understanding.
If you are the maintainer of this site, please check your database settings in the settings.php file and ensure that your hosting provider's database server is running. For more help, see the handbook, or contact your hosting provider.
In BOA, all sites have the same alias, basically a symlink, redirecting like this...
www.example.com -> example.com