[chef] Re: Re: Re: Re: Starting out with the opscode platform.

[Tim Uckun < >]

> I would ask why you need to set the ip address and host name and where
> else could you put it?

I am just using that as an example. It could be any variable like to
location of the backup file, the name of the user that the
applications are deployed under, etc.

Basically every host has some unique requirements and settings.

>
> If you've only got a couple of actual nodes then, by all means, set
> the details in a recipe. But the point of chef is that you can manage
> hundreds or thousands of nodes.
>
> to know about the app servers, say). This means you need to write
> something to find it. You could have your nodes register with the DNS
> server or you could call an API on your load balancer. Lastly, your
> load balancer could query chef to find out what IP addresses it needs.
> I've not used it but Chef has a search function so you could write
> something that looks for all nodes with the app-server role. In the
> load balancer chef recipe you iterate that list and write a config
> file with it.

I'll have to think about this a while and see how I can make it fit.

Like I said right now I am able to specify global configurations like
load_balancer_ip and load_balancer_traffic_subnet and then I can
reference those in the various templates that nodes use to manage
their resources.

I also have overrides for those variables and additional variables on
a per host basis.

For example in my case the load balancer is managed by rackspace.
Rackspace tells me what subnets to expect the traffic from and the IP
of the load balancer. Every host that is being that load balancer has
to have an IPtables rule to accept traffic from the subnets for that
load balancer.