[chef] Re: Re: Re: Re: updated_by_last action from a resource inside a LWP

[Peter Donald < >]

Hi,

On Tue, Jul 17, 2012 at 1:30 AM,  
<
 >
 wrote:
> yfeldblum pointed me to a great pattern for dealing with this.  Here is the
> gist
>
> https://gist.github.com/d85be145f3ff824ccc07/0e97d44f20ec65411b141cb46cbeb19bb34b44ad
>
> The general idea is you cache your current run_context, create a new one, 
> blank
> out the resource collection, perform all your resource actions.  Then you
> restore the run_context back to the original and converge on the new run
> context you created.  This sub run context contains the subset of resources
> acted upon in your provider.  Then you call converge on the sub run context 
> and
> check each of its resources to see if they were updated.  If any did get
> updated you pass that along to your new_resource.
>
> Awesome and nifty.  I implemented in my redisio cookbook in the install
> provider and it seems to work great.

Awesome indeed. I have tested it out and it works fine and dandy for
me. Except we have lots of LWRPs so doing this everytime would be
tiresome. I abstracted the essential goodness into a method
notifying_action and now most of my providers look something like

notifying_action :run do
  file "/tmp/something" do
    owner "root"
    group "root"
    mode "0755"
    action :create
  end
end

Much nicer!

Anyhoo I documented for posterity at

http://realityforge.org/code/2012/07/17/lwrp-notify-on-changed-resources.html

-- 
Cheers,

Peter Donald