ResourceGroup attributes references not validated

[Steven Hardy]

When using the "attributes" interface of ResourceGroup, no validation of the attributes schema (or outputs in the case of a nested stack) is performed, so we fail slow in the event that there's an error in the template.

For example:

heat_template_version: 2014-10-16
resources:
  Controller:
    type: OS::Heat::ResourceGroup
    properties:
      count: 1
      resource_def:
        type: OS::Heat::RandomString

  ANested:
    type: nested.yaml
    properties:
      random_values: {get_attr: [Controller, attributes, valuex]}

Where nested.yaml is (dummy empty template just for the reproducer):

heat_template_version: 2014-10-16
parameters:
  random_values:
    type: json

The typo "valuex" isn't caught during validation, so the stack create starts and we go to CREATE_FAILED, not a big deal in this case, but I discovered this working on TripleO templates where such a fail-slow situation is much less convenient :)

[Steve Baker (steve-stevebaker)]

This may be hard to fix since some resources have a dynamic attributes schema (such as deployment resources, where arbitrary outputs become attributes). There is a danger of over-validating templates which used to work just fine.

[kumari paluru (kumari-paluru)]

Hi..
 I tried with the template. It is working fine.
heat_template_version: 2014-10-16
resources:
  Controller:
    type: OS::Heat::ResourceGroup
    properties:
      count: 1
      resource_def:
        type: OS::Heat::RandomString

  ANested:
    type: nested.yaml
    properties:
      random_values: {get_attr: [Controller, value]}