Nested stacks can be used to create billions of resources

[Clint Byrum]

Even once bug #1214239 is fixed, 3 levels of nesting a 10000 stack-stack could produce 1 trillion resources. Even if template sizes are limited to 256kB, that will allow 2500 stacks per nested stack, so 15 billion+ nested stacks.

We should impose a limit on the numer of resources per top level stack. I think 10000 would be a reasonable number and allow extremely complicated stacks to be deployed.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/44227

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/44228

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/45343

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/45366

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/45462

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/44227
Committed: http://github.com/openstack/heat/commit/8f528704e154c9927c7f2bcd6bc25ea3fb100ae4
Submitter: Jenkins
Branch: master

commit 8f528704e154c9927c7f2bcd6bc25ea3fb100ae4
Author: Clint Byrum <email address hidden>
Date: Thu Sep 5 15:02:32 2013 -0700

    Add methods to help calculate a stack's resources

    In order to limit a stack's size in future changes, we need to know
    how many resources are already in the stack. We also need to be able
    to find the root stack object of a nested stack.

    Change-Id: Ib848bcd2e10d02dffc30dce45a2675a9f718fa7d
    Related-Bug: #1215100

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/44228
Committed: http://github.com/openstack/heat/commit/ecf3954d2320fc79797d83873805168b8c837a8a
Submitter: Jenkins
Branch: master

commit ecf3954d2320fc79797d83873805168b8c837a8a
Author: Clint Byrum <email address hidden>
Date: Thu Sep 5 15:07:47 2013 -0700

    Provide config option to limit resources per stack

    This provides an upper bounds on the number of resources a root level
    stack can contain. The limitation is only applied to the engine creation
    point so that existing stacks that are over the limit in the database
    will not cause problems. Nested stacks will be addressed in a follow-up
    patch.

    Partial-Bug: #1215100
    Change-Id: I1adcb22cf9bd5750b4ae3f219dd3264d1d02c1fc

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/45343
Committed: http://github.com/openstack/heat/commit/ee154544a23ad61318b38b2cebc2cfef60e20b00
Submitter: Jenkins
Branch: master

commit ee154544a23ad61318b38b2cebc2cfef60e20b00
Author: Clint Byrum <email address hidden>
Date: Thu Sep 5 15:10:16 2013 -0700

    Limit resources per stack in nested stacks

    In an earlier patch, the root stack creation was limited by the
    max_resources_per_stack config setting. Now we need to apply the same
    limit for nested stacks.

    Change-Id: I2f871a5d5f4c51dd9cd7c93e94f8b0c8d87fa069
    Partial-Bug: #1215100

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/45366
Committed: http://github.com/openstack/heat/commit/89bb14f49996c7a2bfe76d0067c46823be77b675
Submitter: Jenkins
Branch: master

commit 89bb14f49996c7a2bfe76d0067c46823be77b675
Author: Clint Byrum <email address hidden>
Date: Thu Sep 5 20:00:56 2013 -0700

    Stop stack updates from exceeding resource limit

    Previous patches raise an error when a newly created stack would exceed
    the limit. This one applies the same logic during an update. Note that
    nested stack updates will be handled in another patch.

    Change-Id: Ic5d32501f582640cb77629b902c32c8cb9c20b42
    Partial-Bug: #1215100

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/45462
Committed: http://github.com/openstack/heat/commit/f2ade590075138d524b14a2a909907ea01f346cd
Submitter: Jenkins
Branch: master

commit f2ade590075138d524b14a2a909907ea01f346cd
Author: Clint Byrum <email address hidden>
Date: Fri Sep 6 09:30:44 2013 -0700

    Stop nested stack updates exceeding resource limit

    This is the final way for a user to exceed the max_resources_per_stack
    configuration value.

    Fixes bug #1215100

    Change-Id: I5e0f86c1ad6d74c2fcb3aa2de1028ec93b3e2dd6