dnscontrol/documentation/functions/domain/CNAME.md

name	parameters	parameter_types
CNAME	name target modifiers...	name target modifiers... string string RecordModifier[]

CNAME adds a CNAME record to the domain. The name should be the relative label for the domain. Using @ or * for CNAME records is not recommended, as different providers support them differently.

Target should be a string representing the CNAME target. If it is a single label we will assume it is a relative name on the current domain. If it contains any dots, it should be a fully qualified domain name, ending with a ..

D("example.com", REGISTRAR, DnsProvider("R53"),
  CNAME("foo", "google.com."), // foo.example.com -> google.com
  CNAME("abc", "@"), // abc.example.com -> example.com
  CNAME("def", "test"), // def.example.com -> test.example.com
);