Infinitely recursing stacks reach python's maximum recursion depth

[Clint Byrum]

Steps to reproduce:

* Create a template like this:

Resources:
  C0:
    Type: AWS::CloudFormation::Stack
    Properties:
      TemplateURL: http://someplace/you/control/template.yaml

* Put this template in the URL above so that heat-engine can access it.
* Create a stack with this template

It will recursively download and try to deploy until this is printed in heat-engine's log:

2013-08-20 04:38:01.570 13720 TRACE heat.engine.resource RuntimeError: maximum recursion depth exceeded while calling a Python object

The stack will be 'stuck' in the CREATE/IN PROGRESS state, and can be deleted.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/43044

[Steven Hardy (shardy)]

lifeless raised a bug on this topic a while back, but I can't find it atm, IIRC maybe it expired incomplete as it didn't provide any method to reproduce.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/43044
Committed: http://github.com/openstack/heat/commit/b1b31f170b2256cb73b330341b143f1299e424dd
Submitter: Jenkins
Branch: master

commit b1b31f170b2256cb73b330341b143f1299e424dd
Author: Clint Byrum <email address hidden>
Date: Tue Aug 27 09:10:54 2013 -0700

    Provide user control for maximum nesting depth

    In the case of an infinitely recursing stack, Heat will continue to
    keep nesting stacks until python's maximum stack recursion depth
    is reached. By this point a lot of memory and time may have been
    spent parsing/loading/etc.

    The default of 3 is enough to deploy a stack of stacks of stacks. It
    can be raised by deployers if there is a desire to do larger and more
    complicated stacks, at the cost of more resource utilization.

    Fixes bug #1214239

    Change-Id: Ic492ef84b94b1f715c49eef7e1794a486fb8182f