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

[Guy Paz]

We are seeing some bad behavior of Heat Stack Check->Update .
If user do Check Stack he will lost all Outputs params for Resource Type (Template Resource)

For example (Hot Templates attached) , we have Resource B that get some param from Resource A and I m doing Check Stack and then Update Stack – Resource B need to get the param from Resource A and now this param is null/empty,
So stack update will use empty value and will fail !

I able to create very simple Heat Template that reproduce this problem.
Resource B getting the IP from resource A and create a VM with this name.

To reproduce:
Scenario 1:
- Create the stack (you can see that B vm name created with the output IP from A)
- Execute 'Check Stack'(at this point you will see that output value for A is - empty: Horizon-> Resourse A -> Overview -> Outputs)
- Update stack with the original template.
- Update Failed

Scenario 2:
- Create the stack
- Remove VM B (that has name IP from A)
- Execute 'Check Stack' (at this point you will see that output from A is empty)
- Update stack with the original template.
- You will see that B will not get the IP/Name from A like it was when we deploy the stack.

My expectation is that B will created with the same values (name in this case) like he had in 'create'.

NOTE that If I ll do only check and then update we are getting update failed since now name is null:
"resources.resource_B: BadRequest: resources.server: Server name has a minimum character requirement of 1. (HTTP 400) (Request-ID: req-3950e5c0-c04f-4292-b93f-b3b9d24a5a36)"

and this is the exception:
 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

[Thomas Herve (therve)]

To confirm, the problem is on Kilo, correct?

[Guy Paz (guy-paz)]

It is in Kilo.
solved in Mitaka (I test it yesterday).
Maybe it was a bug that solved already on Liberty/Mitaka ..

I m trying to check on Liberty (having some issues with my Devstack).
when I switched Liberty I m getting : "Could not load heat_template_version.2016-04-08: 'module' object has no attribute 'HOTemplate20160408'"

[Thomas Herve (therve)]

I suspect it's a duplicate of https://bugs.launchpad.net/heat/+bug/1505054