We have item key system.hostname (which returns the hostname) for use in HostMetadata and HostMetadataItem in agent configuration file. Please add two new item keys system.dnsdomainname (should return the dnsdomain name of host i.e, fully qualified domain name only) and system.nisdomainname (should return the yp/nis domain name of the host). These two new item keys will help in validating agent autoregistration process in a distributed environment setups.

Note: For distributed environments, we can validate agents by proxy in autoregistration, but for a smaller fleet distributed infrastructure, validating based on item keys is preferable as it eliminates the need of a proxy.