[Server-devel] fixing the installation instructions

[Martin Langhoff]

On Tue, Jul 21, 2009 at 6:58 PM, Daniel Drake<dsd at laptop.org> wrote:
> I just had a go at fixing the page:
> http://wiki.laptop.org/index.php?title=XS_Installing_Software&diff=212755&oldid=212729
> Please review.

Thanks! Makes sense.

(I've been away for a few days as you've probably noticed. Now I am
trying to get XS-0.6 out of the door, which simplifies all the process
significantly.)


> The page now explicitly states the XS position on DNS - i.e. don't
> need to do anything because the XS does it for you. However, some
> people may want to use ISP dns servers. It would be nice to see
> instructions for such users, but the current ones were incorrect. (the
> way to do it would be to configure bind to send all requests to an
> upstream server.)

Yes. We need a canonical list of the names that need to be set on the
external DNS.

> I am personally confused by issues surrounding hostname resolution of
> the local server. Deployments will usually make up hostnames, right?

The expectation is that they'll make up the leftmost bit of the domain
name, so that the _hostname_ is always 'schoolserver'.

> In which case they don't resolve on the out-of-the-box XS setup, yes?
> Does ejabberd really fail if it can't resolve the hostname?
>
> In Paraguay, we modified /etc/hosts on all XSs as follows:
> 127.0.0.1
> schoolserver.escuelaXX.caacupe.paraguayeduca.org schoolserver
> localhost.localdomain localhost
>
> i.e. we added the FQDN (as stated in /etc/sysconfig/hostname) to the
> very front of the 127.0.0.1 resolution (must be the first entry,
> because I couldn't find any other way to get "hostname -s" and
> "hostname -f" working correctly), then we added the unqualified
> hostname "schoolserver."

On 0.6 the domain_config scripts do that as well, IIRC.

> If I remember correctly, this was done in order to make puppet work.
> Maybe these are puppet and ejabberd bugs, but it doesn't seem
> unreasonable for applications to require the local hostname being
> correctly resolvable and the hostname being correctly output by the
> hostname program.

Yep. Though there's a bit of trickery in that schoolserver != localhost.

> Finally I commented out the instructions explaining how to fix
> ejabberd when the user changes the hostname, because they were
> incorrect. The solution would be to re-run domain_config and then fix
> the Mnesia DBs, but I'm not sure if re-running domain_config is
> advisable or if a certain flag needs to be used or something. It would
> be nice to see these instructions return if someone is in-the-know or
> can experiment. Alternatively we could wait for XS_0.6 as trac
> suggests that this is no longer an issue.

The new domain_config clears out mnesia -- all of it is re-creatable anyway.

cheers,


m
-- 
 martin.langhoff at gmail.com
 martin at laptop.org -- School Server Architect
 - ask interesting questions
 - don't get distracted with shiny stuff  - working code first
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