In certain scenarios facter will make strange decisions in determining the value for the fqdn (and domain) fact. This can lead to misleading results.

In a NIS environment when a host is under a subdomin facter will use ‘domainname’ to determine the domain fact and then use that to set the fqdn fact. domainname (the command) will return the configured nis domain or “(none)” if no nis domain is configured.

— Example 1 — host in nis environment with subdomain

hostname¶

foo.bar.example.com

domainname¶

example.com

facter domain¶

example.com

facter fqdn¶

foo.example.com

— Example 2 — non-nis environment

hostname¶

foo.bar.example.com

domainname¶

(none)

facter domain¶

bar.example.com

facter fqdn¶

foo.bar.example.com

It seems that facter should use hostname if it’s set (and fully qualified) to determine the fqdn rather then try to build it from pieces. Assuming hostname is only reporting short hostname then building it from domainname is in consistent.

facter version: facter-1.5.2-1.el5 host os: rhel5