Can't import ResourceGroup index to list index in get_param

[Steven Hardy]

When creating a RandomString resource, we assume all values in the properties are available during validate(), but this is not true when you reference certain properties e.g length via get_param inside a nested stack:

https://review.openstack.org/#/c/301623/2

This shows the problem, which fails with:

ERROR: Failed to validate: Failed to validate: resources[0]: Value '' is not an integer

ERROR heat.engine.stack [req-21a6c303-1282-4dc2-afe5-19e3e9ea5973 None admin] Exception: Value '' is not an integer
2016-04-05 14:40:36.316 TRACE heat.engine.stack Traceback (most recent call last):
2016-04-05 14:40:36.316 TRACE heat.engine.stack File "/opt/stack/heat/heat/engine/stack.py", line 753, in validate
2016-04-05 14:40:36.316 TRACE heat.engine.stack result = res.validate()
2016-04-05 14:40:36.316 TRACE heat.engine.stack File "/opt/stack/heat/heat/engine/resources/openstack/heat/random_string.py", line 273, in validate
2016-04-05 14:40:36.316 TRACE heat.engine.stack length = self.properties[self.LENGTH]
2016-04-05 14:40:36.316 TRACE heat.engine.stack File "/opt/stack/heat/heat/engine/properties.py", line 453, in __getitem__
2016-04-05 14:40:36.316 TRACE heat.engine.stack return self._get_property_value(key)
2016-04-05 14:40:36.316 TRACE heat.engine.stack File "/opt/stack/heat/heat/engine/properties.py", line 446, in _get_property_value
2016-04-05 14:40:36.316 TRACE heat.engine.stack return self.get_user_value(key, validate)
2016-04-05 14:40:36.316 TRACE heat.engine.stack File "/opt/stack/heat/heat/engine/properties.py", line 438, in get_user_value
2016-04-05 14:40:36.316 TRACE heat.engine.stack raise ValueError(six.text_type(e))
2016-04-05 14:40:36.316 TRACE heat.engine.stack ValueError: Value '' is not an integer
2016-04-05 14:40:36.316 TRACE heat.engine.stack

The problem AFAICT is that random_string.py shouldn't fail in validate(), because the check for self.properties[self.LENGTH] may fail to get a value to validate until create.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/302042

[Rico Lin (rico-lin)]

This bug is discovered by [1].
After some trace, I found out that we surprisely didn't support length: {get_param: [lengths, '1']}
this can lead to length: {get_param: [lengths, {get_param: index}]} in [1] raise error and didn't know what to do in this RG case.
This means that we now have a way to import "%index%" to a list index in get_param

[1]https://review.openstack.org/#/c/301623/2

[Rico Lin (rico-lin)]

Steven
I change the title from `RandomString validation happens to early` to `Can't import ResourceGroup index to list index in get_param`.
Since IMO we can have better understanding of this bug. Feel free to change back if it's not appropriated.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/302042
Committed: https://git.openstack.org/cgit/openstack/heat/commit/?id=1df6d2aa7984035015391abe13f86b8980035b92
Submitter: Jenkins
Branch: master

commit 1df6d2aa7984035015391abe13f86b8980035b92
Author: ricolin <email address hidden>
Date: Wed Apr 6 14:00:44 2016 +0800

    Support string index for list in get_param

    Accept for string index like '1' for list in get_param function
    For example, with lengths equal to [4,5,6]. We can write down something
    like this: `length: {get_param: [lengths,'1']}`.
    Closes-Bug: #1566321

    Change-Id: I52447dea93ff2e6a32d597a632093661feed7c71

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/mitaka
Review: https://review.openstack.org/302956

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/liberty
Review: https://review.openstack.org/302963

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/302956
Committed: https://git.openstack.org/cgit/openstack/heat/commit/?id=f71f912a95860bd7a0efba2ea2c7b383bddca0bd
Submitter: Jenkins
Branch: stable/mitaka

commit f71f912a95860bd7a0efba2ea2c7b383bddca0bd
Author: ricolin <email address hidden>
Date: Wed Apr 6 14:00:44 2016 +0800

    Support string index for list in get_param

    Accept for string index like '1' for list in get_param function
    For example, with lengths equal to [4,5,6]. We can write down something
    like this: `length: {get_param: [lengths,'1']}`.
    Closes-Bug: #1566321
    Depends-On: I14377e0497f1589f1234226babcf7d78761b7b7b

    Change-Id: I52447dea93ff2e6a32d597a632093661feed7c71

[Doug Hellmann (doug-hellmann)]

This issue was fixed in the openstack/heat 7.0.0.0b1 development milestone.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/302963
Committed: https://git.openstack.org/cgit/openstack/heat/commit/?id=e13e00734d2d563b18ed7428527f1c67f5b8e686
Submitter: Jenkins
Branch: stable/liberty

commit e13e00734d2d563b18ed7428527f1c67f5b8e686
Author: ricolin <email address hidden>
Date: Wed Apr 6 14:00:44 2016 +0800

    Support string index for list in get_param

    Accept for string index like '1' for list in get_param function
    For example, with lengths equal to [4,5,6]. We can write down something
    like this: `length: {get_param: [lengths,'1']}`.
    Closes-Bug: #1566321

    Change-Id: I52447dea93ff2e6a32d597a632093661feed7c71

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/heat 6.1.0 release.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/heat 5.0.2 release.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/heat 6.1.0 release.