[chef] Re: Re: Ideas on kickstarting a node and auto-applying a role

[Paul Choi < >]

On 5/14/10 11:37 AM, John Merrells wrote:
> On May 14, 2010, at 11:11 AM, Paul Choi wrote:
>
>    
> > We want to be able to do something similar with Chef - the goal being, 
> > kickstart a host, then install Chef RPMs, then the host should just 
> > automagically get configured according to its IP, hostname, or some kind of 
> > identifying criteria. Any ideas on how to do this?
> >      
> I'm doing this, so it is possible.
>
>    
> > So far, the workflow that Chef expects is:
> >   - install chef-client on node.
> >   - chef-client auto-registers itself with either validation cert or password
> >   - Use knife to apply role(s) to the newly created node
> >      
> This is what I do, except for the last part.
>
> I have a separate piece of code that is driven by a data file that maps 
> virtual hosts onto virtual servers onto physical machines. The code sets up 
> the name servers, creates the machines through my hosting provider API and 
> sets up the roles for the servers in chef. You can actually create the nodes 
> before the client actually connects for the first time. The common key 
> between the virtual and the physical is the hostname of the machine. I know 
> what the machine name will be e.g 'webserver6' and the boot script names the 
> machine that before the chef client code is installed.
>    
That's good to know, thanks.
> > It's the manual application of role(s) to the newly created node that I would like to 
> > see automated. I don't think there's a way in Chef to set a rule saying, "if a 
> > host is in 10.1.12.* subnet, apply role[a], role[b], role[z], etc". If I can 
> > figure out this last step, life would be just awesome. :)
> >      
>
> You might be able to do this by writing some ruby code in a role file..... 
> I'm not sure how the chef client determines which cookbooks to download from 
> the server... it might be static.... others on the list can probably answer 
> this.
>
> However, I'd have thought that basing roles on ip addresses is going to 
> remove some flexibility that you might need later on.
>
>    
Since our servers are not in the cloud, it's actually good for us to tie 
stuff to host IP. The firewall allows access based on IP, and physical 
server specs are different based on their role.

As for cookbooks, I might be misunderstanding what you are saying, but 
after applying the correct roles to a node, recipes are applied 
according to the run list. I think that's what I'm looking for, unless 
there's more flexibility with downloading cookbooks that you might want 
to tell me about.
> John
>
>