[chef] Re: Using data generated in a LWRP

[Andrea Campi < >]

On Mon, Apr 2, 2012 at 7:21 PM, Nick Peirson 
<
 >
 wrote:
> Hi all,
>
> I've only been using chef for a couple of months, so bear with me if I
> mangle the terminology :)
>
> I've got a LWRP that's creating an AWS RDS instance. Within the LWRP I wait
> till the RDS instance becomes available (while loop + sleep) and get it's
> details, of which I'm particularly interested in the endpoint address. I can
> log this by doing something along the lines of:
>
> Chef::Log.info("RDS endpoint address is #{rds_instance[:endpoint_address]}")
>
> What I now want to do is subscribe to the resource that's using this
> provider to create the rds_instance and for the subscribing resource to have
> the rds_instance object available, particularly the endpoint address. The
> subscribing resource is then going to connect to the RDS instance create a
> database, set up some permissions, etc.
>
> Is there a way to pass this information, e.g. something along the lines of
> making the rds_instance object available? If not, my other thought is to
> store it on the node or in a data bag, but this seems like a hack to get
> round a limitation that's only there due to my lack of knowledge.

The interesting thing is that the Notification object (which is used
to keep track of queued notifications) holds a reference to resource
that triggered the notification.
You can see that in the logs:

        Chef::Log.info( "#{notification.notifying_resource} sending
#{notification.action}"\
                        " action to #{notification.resource} (delayed)")

However when it's time to call run_action, that reference is dropped.

We could store a reference to either the Notification or
notification.notifying_resource in the run_context, so that the
notified resource could access it.
I don't see a real downside here, and it.

Thoughts?


Andrea