Fix Provider updated_by_last_action return value

[phlipper]

This PR uses the return value from the executed resource vs. hard-coding a true/false return.

[coveralls]

Coverage remained the same at 100.0% when pulling 9b641bd on phlipper:provider-notification into b2824ae on DataDog:master.

[coveralls]

Coverage remained the same at 100.0% when pulling 9b641bd on phlipper:provider-notification into b2824ae on DataDog:master.

[miketheman]

This commit does a lot more than update the action, it changes style as well.
Not saying that the change isn't welcome, but sectioning them to behavior vs style changes is a better approach, as they can be diff'ed accordingly.

[phlipper]

@miketheman are you asking me to change this PR now, or are you just commenting generally?

[miketheman]

I think I'm commenting in general. i've been working through a bunch of bug tickets here, and commenting on issues as I notice things.
I may split & rebase the code so that it does that when I get to this feature.

[olivielpeau]

@phlipper Unfortunately this approach doesn't change the current behavior because t.updated_by_last_action? is evaluated during the compile phase and therefore always evaluates to false. For reference see chef/chef#3748.

A comment on the above issue recommends using use_inline_resources instead, but it has the drawbacks of only working on Chef >= 11 and of not allowing external resources to be notified inside of the LWRP (see https://docs.chef.io/lwrp.html#disable). As the behavior of use_inline_resources will be the default one in future versions of Chef we should think about handling it though (maybe by notifying the datadog-agent service when datadog_monitor is used, or by using definitions).

Also, for reference, this email on the chef mailing list recommends running the embedded resource of the LWRP before evaluating updated_by_last_action? on it, but this approach has the same drawback of not allowing to notify external resources in the embedded resource.

@miketheman Any thoughts on this?

[miketheman]

@olivielpeau The current cookbook aims to support Chef 10, so a pattern used there is:

use_inline_resources if defined?(use_inline_resources)

This pattern dates back a while.

So I think the final desire could be accomplished using the inline resources approach, as long as it's qualified.

There's also this post on the approach.