[chef] Re: A proof of concept cookbook for the on_failure Chef RFC

[Kannan Manickam < >]

Hello Dan,

Thanks for your ideas.

My responses are inline.

On Apr 9, 2014, at 12:12 PM, Dan Razzell < "> > wrote:

Nice.  A processing path for resource failures has been conspicuously absent in Chef, and workarounds require painfully awkward management of success counters.

I appreciate that, in keeping with the spirit of convergence, the on_failure attribute is designed to retry the original resource once its block completes.  But there's another, lower level use case that more closely resembles notification, only for failure.  Indeed it would be best implemented as an :on_failure option for the notifies and subscribes attributes.

That is one way to do it but that limits on what we can do during the failure. This implementation can contain arbitrary ruby code. Let’s see what others think.

That discussion would be somewhat out of scope for the on_failure RFC, except that a very similar effect could be had if on_failure supported something like a noretry option.  It would be clear from this option that the original resource was not to be retried on completion of the specified block.  Control would return to the resource, however, so that in the ordinary way, depending on the value for ignore_failure, it would either continue the recipe or raise an exception.

I was also thinking about something like this. There might be cases where you want to make sure some steps are done before the Chef run fails. I currently use a Chef handler for this and wrote a blog post here: http://blog.arangamani.net/blog/2014/03/30/writing-custom-chef-handlers/. So the `noretry` option would simply execute the block and raise the original exception.

Thanks,
Dan

On 14-04-09 12:37 AM, Kannan Manickam wrote:

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I have playing with a proof of concept cookbook for the on_failure Chef RFC proposed recently. I made some good progress on that and it works for most use cases. So I just wanted to share it with everybody.

Here is the: https://github.com/arangamani-cookbooks/on_failure
I published it to the community site: http://community.opscode.com/cookbooks/on_failure

And I wrote the following blog post that explains how this works including some demonstration.
http://blog.arangamani.net/blog/2014/04/08/chef-on-failure-handler/

Thanks Steven, Paul, and Seth for providing awesome examples in the RFC.

Cheers,
Kannan.

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