The top level of your Config file is a
services key whose value
is a list of Services.
Service names are arbitrary, but they act as the internal host name for the Service. This is the name other Services in the Preview would use to refer to the Service. As a result, there are a few rules you must observe when naming Services:
As an example, a set of Services that serve a PHP-based site with a MySQL database and a Redis cache might be: