[chef] Re: Modelling a collection of resources as an LWRP

[Adam Jacob < >]

On Mon, Feb 14, 2011 at 1:01 PM, Mark J. Reed 
<
 >
 wrote:
> I have a set of resources that I want to invoke as a single unit, that will
> notify other resources if any of the sub-resources would do so.
> One such set could be modeled as its own recipe, I want to be able to
> include multiple instances in other recipes - and you can only include
> another given recipe once.
> So I was thinking an LWRP.  Say I want to create a group, a user who belongs
> to that group, a file owned by that user, and a service that requires that
> file to exist, in one swell foop.  The provider could look like this:
> action :create do
>     resources = Hash.new []
>     resources[:create]  <<
>        group "foo" do ... end    <<
>        user "bar" do ... end     <<
>        file "baz" do ... end
>     resources[:enable] = resources[:start] << service "zoo" do ... end
>     resources.each do |action, res|
>         res.run_action action
>        
> 
 (
> @new_resource.updated_by_last_action? || res.updated_by_last_action? )
>     end
> end
> It seems kind of hacky to force all the resources to run immediately just so
> I can query their updated_by_last_action status.  Is there a better way?

If the only real goal here is to fire a notification if a set of
resources change, you should just include the notification on all the
resources - either through being explicit about it (specifying it in
each resource declaration) or in a loop.  No need to run the actions
in advance, Chef is smart enough to group together the notifications.

Adam

-- 
Opscode, Inc.
Adam Jacob, Chief Product Officer
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