Vps – Best practices for setting hostname and domainname in a VPS

networkingvps

I’m quite experienced managing Linux on standalone machines and in local networks.

Recently I’ve hired a VPS server running Linux and also a domain name and I have a few questions regarding the hostname and domainname commands.

Right now my domain name (e.g. foobar.com) is pointed to the IP address of my VPS (e.g. 1.23.45.67). Additionally, my VPS has an assigned host name (e.g. virt1000) with the hosting company domain name (hostingcompany.com). Therefore, there are two ways I can SSH to my VPS:

$ ssh -l user virt1000.hostingcompany.com
$ ssh -l user foobar.com

I have changed the domain name to be foobar.com from the command line and the host name to another one (e.g. mynicehost). Should I add mynicehost.foobar.com to /etc/hosts/ and also set up the subdomain mynicehost.foobar.com in the A records from my domain?

I’m asking for best practices, really. As it stands, everything kind of works (the domain takes you to the right web site, etc.).

Thanks in advance.

Best Answer

You appear to have missed the point of my comment, so I'll elaborate in an answer:

Virtual machines are not special. They should be treated like any other physical host.
In other words, if it makes sense for you to set the hostname to mynicehost.foobar.com for a physical machine you should do the same thing for a virtual machine.

The DNS and /etc/hosts question is a matter of personal preference.
Some people will tell you the local hostname should always be in /etc/hosts, others (like me) will say it should alway be in DNS (and generally not in /etc/hosts).

If you are sending mail from the system it is generally important that its hostname be resolvable in DNS (and that the forward A record match the reverse PTR record).

Note that the domainname command probably does not do what you think it does.
The domainname command is historically a NIS thing. If you don't know what NIS is count yourself among the lucky.

Related Solutions

Setting the Hostname: FQDN or Short Name?

I would choose a consistent approach across the entire environment. Both solutions work fine and will remain compatible with most applications. There is a difference in manageability, though.

I go with the short name as the HOSTNAME setting, and set the FQDN as the first column in /etc/hosts for the server's IP, followed by the short name.

I have not encountered many software packages that enforce or display a preference between the two. I find the short name to be cleaner for some applications, specifically logging. Maybe I've been unlucky in seeing internal domains like server.northside.chicago.rizzomanufacturing.com. Who wants to see that in the logs or a shell prompt?

Sometimes, I'm involved in company acquisitions or restructuring where internal domains and/or subdomains change. I like using the short hostname in these cases because logging, kickstarts, printing, systems monitoring, etc. do not need full reconfiguration to account for the new domain names.

A typical RHEL/CentOS server setup for a server named "rizzo" with internal domain "ifp.com", would look like:

/etc/sysconfig/network:
HOSTNAME=rizzo
...

/etc/hosts:
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

172.16.100.13   rizzo.ifp.com rizzo

[root@rizzo ~]# hostname 
rizzo

/var/log/messages snippet:
Dec 15 10:10:13 rizzo proftpd[19675]: 172.16.100.13 (::ffff:206.15.236.182[::ffff:206.15.236.182]) - Preparing to               
 chroot to directory '/app/upload/GREEK'
Dec 15 10:10:51 rizzo proftpd[20660]: 172.16.100.13 (::ffff:12.28.170.2[::ffff:12.28.170.2]) - FTP session opened.
Dec 15 10:10:51 rizzo proftpd[20660]: 172.16.100.13 (::ffff:12.28.170.2[::ffff:12.28.170.2]) - Preparing to chroot                
to directory '/app/upload/ftp/SRRID'

Linux – How to create email accounts via SSH

It's trivially easy to do that with a UNIX MTA, eg sendmail, if you don't mind each email address being associated with an actual user on your system (make the user with useradd; put the aliases in /etc/aliases and run newaliases).

I applaud your decision to get out from under the thumb of cpanel, and I reckon you should be fine doing this if you're OK with hacking virtual hosts into your apache config, which (imho) is a lot fiddlier.

Edit: I wouldn't look for "resources for managing hosting via ssh", because a lot of UNIX guides either take it for granted that you're doing everything from the shell (ie, command line, via SSH), or provide shell alternatives to everything graphical, anyway. If I were you I'd start with the official documentation for whatever distro you're running on your VPS. If you say what that distro is, people may have other good pointers for you.

Best Answer

Related Solutions

Setting the Hostname: FQDN or Short Name?

Linux – How to create email accounts via SSH

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