we rely on a DNS misconfiguration [#894024]

For some reason, we assume that "hostname" and "uname -n" return the FQDN. That is not a proper configuration.

The "hostname" is the short name of the machine. So for a machine designated by foo.example.com, "hostname" (and uname -n) should return "foo" and hostname -f should return foo.example.com.

This is documented in a few places, but just an example:

http://www.debian.org/doc/manuals/debian-reference/ch05.en.html#_the_hos...

We should make sure people configure their /etc/hosts correctly (which we do, i think) and make sure they configure their hostname correctly too (which we don't, and we assume that we set the /etc/hostname to the FQDN, which is wrong).

Comments

Comment #1

anarcat CreditAttribution: anarcat commented 25 October 2010 at 15:54

Status:

Active

» Needs review

Basically, I think this means changing the INSTALL.txt to read this:

  AEGIR_HOST=`hostname -f`
  resolveip $AEGIR_HOST

instead of this:

  AEGIR_HOST=`uname -n`
  resolveip $AEGIR_HOST

Would that be sufficient? Where else did we cook in that assumption?

Comment #2

Anonymous (not verified) CreditAttribution: Anonymous commented 26 October 2010 at 03:12

php_uname is littered all through install.hostmaster.inc, migrate.hostmaster.inc and provision.inc's provision_is_local_host($host) function

Comment #3

Anonymous (not verified) CreditAttribution: Anonymous commented 26 October 2010 at 23:43

The more I think about it, it should *definitely* use the FQDN. I added a remote web server and because uname -n was 'aegir' on my other host (which resolved to the public IP due to /etc/hosts on Rackspace Cloud servers), it was trying to talk back to the database on the main server as 'aegir' and couldn't, obviously until I fudged the hosts on the remote web server.

If it was the FQDN, it would likely 'just work'.

Comment #4

Anonymous (not verified) CreditAttribution: Anonymous commented 28 October 2010 at 22:30

Status:

Needs review

» Needs work

hostname -f ought to work - however the fun won't end there. Slicehost and Rackspace servers, for example, set the fqdn as the name of the server when you create it.

In other words, if I spin up a server called 'aegir-02', the short and fqdn of the server is 'aegir-02'.

Given the popularity of such providers, I think we'd still be obligated to give an example of a hosts fudge to make this work.

Adrian, want to update this ticket on what stuff you were doing with slicehost and puppet around this area?

Comment #5

adrian CreditAttribution: adrian commented 1 November 2010 at 00:34

this could work if we get rid of uname -n

  host { "$hostname" :
    ip => $ipaddress,
    ensure => absent,
  }
  host { "$hostname.$domain" :
    ip => $ipaddress,
    host_aliases => [ $hostname ]
  }

save that to hostname.pp and run puppet hostname.pp as root.