[GTALUG] overengineering: hostnamectl

[D. Hugh Redelmeier]

How do you set the hostname of a Linux machine?  It used to be you just 
put it in the file /etc/hostname.

Now, at least on CentOS, the SystemD way is to use the hostnamectl
command.  There are other ways (GUI and TUI) but I think hostnamectl
is the real way.

This lets you set the real, pretty, and transient name of the host.  I
didn't know those existed.  In fact, there are lots of other options.

The text space of the hostnamectld is 272K (40% larger than the text
editor I use and 2.5 times the size of the hostname command).

You can even change the hostname of other machines and hostnamectl
will use ssh to accomplish this.  I don't see why it is hostnamectl's
job to know how to ssh.

I will admit that the good old days were not that wonderful.  The
hostname(1) manpage lists:
       hostname - show or set the system's host name
       domainname - show or set the system's NIS/YP domain name
       ypdomainname - show or set the system's NIS/YP domain name
       nisdomainname - show or set the system's NIS/YP domain name
       dnsdomainname - show the system's DNS domain name
and a lot of flags.

And there's uname -n.

I remember uuname but that is no longer standard -- you'd have to
install uucp to get that.

Every ethernet interface can have one or more DNS names.

And plenty more that I don't remember.  Kerberos?  SMB?  Hesiod?

To be honest, what bothers me is that there seem to be several
different models of what a hostname is.  It would be nice if we
actually could delete some of these interfaces, and merge some others,
leaving behind only one model.  Maybe the SystemD model is that one.