[chef-dev] Re: Re: Re: Re: MySQL, chef-solo and node.save

[Peter Donald < >]

Hi,

On Thu, Oct 4, 2012 at 12:07 PM, John Vincent
<
 >
 wrote:
> I have a DB server. I have an app server. Under the current Chef model
> (and the design of the official Opscode cookbooks) is that the node
> NEEDS the resource, declares the resource. If I need a db created, a
> migration run or a user created the consumer of that resource (in this
> case the app server) does that work under its Chef cookbooks. Mind you
> I'd argue that the creator of that resource should be the DB server.
> However that's just not possible in the current Chef world. I could
> use Noah to do the orchestration but even I'd admit it's kludgy. What
> we essentially are faced with his how to declare a resource on another
> node from the node that needs it.

This is how we do it for some of our applications. Let's say we have a
node that runs a service that provides resources to other
applications. Say we have a node that runs a message broker that hosts
topics and queues for other applications. We have N application nodes
that as part of their converge will publish override attributes that
declare their requirement for a topic or a queue. The next time the
broker node converges it uses search to pick up all the resources
requested by application nodes and then uses that data to drive the
configuration of the set of queues/topics that the broker hosts. The
releases is often a multi converge process where we first converge the
application nodes (so they publish requirements and disable the app
during an upgrade), converge the resource provider nodes (creating the
resources and possibly doing migrations), then converge the
application nodes (bringing them online using the new resources).

of course we rely fairly heavily on chef server to do this...

-- 
Cheers,

Peter Donald