Ports are not being deleted with clusters

[Davide Agnello]

Executing a cluster creation test with a Rally benchmark of 100x in Devstack reviled ports are not being deleted when respective clusters are being deleted. This test reached the port creation limit which then led to Cluster creation failures due to no being able to create new ports.

Possible solution:
The Cluster Delete work flow should also explicitly delete a Cluster's associated ports.

[Davide Agnello (dagnello)]

Verified issue.

Scenario 1:
1. Created two ports
2. Created a VM and attached both ports from step 1
3. Verified both networks are connected to new VM
4. Issued delete of VM
5. Verified VM was deleted
6. Verified two ports created in step 1 are still around (Cue assumption was ports would be deleted)

Scenario 2:
1. Created one port
2. Created a VM and attached port from step 1
3. Verified network is connected to new VM
4. Issued delete of VM
5. Verified VM was deleted
6. Verified port created in step 1 is still around (should be deleted as per Cue's assumption)

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/182870
Committed: https://git.openstack.org/cgit/stackforge/cue/commit/?id=0dc7db6e80f3f781f008cdfafda9f01cbcfb15b6
Submitter: Jenkins
Branch: master

commit 0dc7db6e80f3f781f008cdfafda9f01cbcfb15b6
Author: dagnello <email address hidden>
Date: Wed May 13 15:05:11 2015 -0700

    Deleting VM ports on cluster delete flow

    - modified delete port task to take a list of ports and delete all
      specified ports as well as taking a single port
    - delete port task also does not throw an exception upon failure to
      delete a port, it instead logs a warning
    - modified delete cluster flow to retrieve a list of ports for a VM and
      attempt to delete each port after deleting the VM

    Change-Id: Ib311b23fdf3a58bc4b79257ed412e9d53d039013
    closes-bug: 1448140