Update stack return empty values value for Template Resource after Check Stack

Issue

What problem/issue/behavior are you having trouble with? What do you expect to see?

Bad behavior can be seen when updating a stack ( Heat Stack Check->Update ).All the Outputs params for Resource Type could be lost depending on the scenario of our stacks.

This could be an exmple setup: There is a Resource B that get some param from Resource A. Performing a Check Stack and then Update Stack – Resource B need to get the param from Resource A and now this param appears as null/empty, then the stack update will use empty value and will fail .

The following traces could be seen on Server B:

 log_http_response /usr/lib/python2.7/site-packages/glanceclient/common/http.py:136
2016-01-14 20:06:16.255 17722 INFO heat.engine.resource [-] UPDATE: Server "server" [b324dac9-6abd-4795-9f4a-b53de09943f1] Stack "test8-resource_B-sa6xqkai65pq" [1b81f309-d8ac-4acb-9583-f9b6dbfe64e3]
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource Traceback (most recent call last):
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource File "/usr/lib/python2.7/site-packages/heat/engine/resource.py", line 543, in _action_recorder
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource yield
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource File "/usr/lib/python2.7/site-packages/heat/engine/resource.py", line 811, in update
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource args=[after, tmpl_diff, prop_diff])
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource File "/usr/lib/python2.7/site-packages/heat/engine/scheduler.py", line 296, in wrapper
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource step = next(subtask)
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource File "/usr/lib/python2.7/site-packages/heat/engine/resource.py", line 584, in action_handler_task
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource handler_data = handler(*args)
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource File "/usr/lib/python2.7/site-packages/heat/engine/resources/openstack/nova/server.py", line 1115, in handle_update
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource self.client_plugin().rename(server, prop_diff[self.NAME])
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource File "/usr/lib/python2.7/site-packages/heat/engine/clients/os/nova.py", line 348, in rename
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource server.update(name)
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource File "/usr/lib/python2.7/site-packages/novaclient/v2/servers.py", line 55, in update
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource self.manager.update(self, name=name)
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource File "/usr/lib/python2.7/site-packages/novaclient/v2/servers.py", line 918, in update
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource return self._update("/servers/%s" % base.getid(server), body, "server")
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource File "/usr/lib/python2.7/site-packages/novaclient/base.py", line 174, in _update
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource _resp, body = self.api.client.put(url, body=body)
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource File "/usr/lib/python2.7/site-packages/novaclient/client.py", line 456, in put
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource return self._cs_request(url, 'PUT', **kwargs)
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource File "/usr/lib/python2.7/site-packages/novaclient/client.py", line 428, in _cs_request
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource resp, body = self._time_request(url, method, **kwargs)
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource File "/usr/lib/python2.7/site-packages/novaclient/client.py", line 397, in _time_request
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource resp, body = self.request(url, method, **kwargs)
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource File "/usr/lib/python2.7/site-packages/novaclient/client.py", line 391, in request
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource raise exceptions.from_response(resp, body, url, method)
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource BadRequest: Server name has a minimum character requirement of 1. (HTTP 400) (Request-ID: req-3950e5c0-c04f-4292-b93f-b3b9d24a5a36)
2016-01-14 20:06:16.255 17722 TRACE heat.engine.resource
2016-01-14 20:06:16.261 17722 DEBUG heat.engine.scheduler [-] Task update_task from Stack "test8" [1e3411a3-7e6d-4ba9-99e2-055faa394b82] running step /usr/lib/python2.7/site-packages/heat/engine/scheduler.py:220
2016-01-14 20:06:16.262 17722 DEBUG heat.engine.scheduler [-] Task Stack "test8" [1e3411a3-7e6d-4ba9-99e2-055faa394b82] Update running step /usr/lib/python2.7/site-packages/heat/engine/scheduler.py:220

Example templates:

[1] test.yaml
heat_template_version: 2013-05-23

description:

parameters:
  public_net_id:
    type: string
    description: ID of public network
    constraints:
      - custom_constraint: neutron.network
        description: Must be a valid network ID
  flavor:
    type: string
    description: Flavor to use
    constraints:
      - custom_constraint: nova.flavor
        description: Must be a valid flavor name
  image:
    type: string
    description: Name of image to use
    constraints:
      - custom_constraint: glance.image
        description: Must be a valid image name

resources:
  server:
    type: OS::Nova::Server
    properties:
      networks:
      - port:
          get_resource: server_port
      name: server_A
      image: { get_param: image }
      flavor: { get_param: flavor }

  server_port:  
    type: OS::Neutron::Port
    properties:
      network_id: { get_param: public_net_id }

outputs:
  ip_A:
    description: IP address A server
    value: { get_attr: [ server, first_address ] }
  image_A:
    value: { get_param: image }


[2] env.yaml
parameters:
  flavor: m1.demo
  image: cirros 

  public_net_id: b54b1eb9-8076-4b3a-92d3-1d5725b03fad