We can run one instance of Nginx in front of another to provide a layer of caching. This requires:
- create a directory for cached files
- apply the cache configuration for the server block
It is not necessary to pass the cache status in the response header, but it's helpful in building.
Also, note the pass_through name is special http://demo_nginx
as this is a Docker project. In a normal server setting, that is an IP address.