block search engine indexing on all sub-domain
I host many demo site on a single droplet like this, for examples
they all use demosite.com as the domain
How can I block search engine from indexing all my website with in that domain?
Is it possible to do in DigitalOcean's control panel or I have to do it on Nginx?
I know it possible to manually block search engine for each one of them. However, sometimes I forgot to manually block it and need to make sure that my demo site don't affect the SEO of the real one.