Description of problem:

We have two network-environment files, stage and prod. Originally the overcloud was deployed using the prod network-environment files.

Then someone has run the overcloud deployment on top of prod environment with stage network-environment file. Which created new subnets and networks related to stage environment.

Undercloud then see duplicated neutron networks from both stage and prod environment:

$ neutron subnet-list
+--------------------------------------+---------------------+-----------------+-----------------------------------------------------+
| id                                   | name                | cidr            | allocation_pools                                    |
+--------------------------------------+---------------------+-----------------+-----------------------------------------------------+
| 22dc1807-5669-4a3b-9578-506bd3f7619a | storage_mgmt_subnet | 192.168.202.0/24 | {"start": "192.168.202.11", "end": "192.168.202.250"} |
| 32f483ec-9306-4bb5-a5e6-037c09bfda91 | tenant_subnet       | 192.168.201.0/24 | {"start": "192.168.201.11", "end": "192.168.201.250"} |
| 41802666-6d63-4611-bef4-e5b364553565 | internal_api_subnet | 192.168.204.0/24 | {"start": "192.168.204.11", "end": "192.168.204.250"} |
| 45876116-a72b-4f05-92f7-091a2fd68ef8 | storage_subnet      | 192.168.103.0/24 | {"start": "192.168.103.11", "end": "192.168.103.250"} |
| 47f66366-221d-4ca1-81d7-736c4dc62650 | internal_api_subnet | 192.168.104.0/24 | {"start": "192.168.104.11", "end": "192.168.104.250"} |
| 4bd8c967-f99c-49a1-9ecb-a5559e0779d4 |                     | 10.1.38.0/24    | {"start": "10.1.38.20", "end": "10.1.38.120"}       |
| 6cc46f60-5a23-45b2-9d98-fb88075a886b | storage_mgmt_subnet | 192.168.102.0/24 | {"start": "192.168.102.11", "end": "192.168.102.250"} |
| a7ce3bfe-0779-4b0d-9188-0d025e022042 | external_subnet     | 10.2.188.0/24   | {"start": "10.2.188.11", "end": "10.2.188.253"}     |
| b2bdc779-c946-4782-9977-21e789fd2be9 | external_subnet     | 10.2.188.0/24   | {"start": "10.2.188.11", "end": "10.2.188.253"}     |
| c83303c7-571e-4933-9d4b-eaf4f4cd519b | tenant_subnet       | 192.168.101.0/24 | {"start": "192.168.101.11", "end": "192.168.101.250"} |
+--------------------------------------+---------------------+-----------------+-----------------------------------------------------+

We have deleted all the duplicate subnets that matched the incorrect (staging) settings, and attempted a full stack update, unfortunately we hit the following error:

Deploying templates in the directory /home/stack/centralci-openstack-templates/templates                                                         
Stack failed with status: resources.Networks: resources.StorageNetwork: Conflict: resources.StorageSubnet: Unable to complete operation on subnet
45876116-a72b-4f05-92f7-091a2fd68ef8. One or more ports have an IP allocation from this subnet.                                      


Version-Release number of selected component (if applicable):

openstack-heat-api-2015.1.4-1.el7ost.noarch
openstack-heat-api-cfn-2015.1.4-1.el7ost.noarch
openstack-heat-api-cloudwatch-2015.1.4-1.el7ost.noarch
openstack-heat-common-2015.1.4-1.el7ost.noarch
openstack-heat-engine-2015.1.4-1.el7ost.noarch
openstack-heat-templates-0-0.8.20150605git.el7ost.noarch
openstack-tripleo-heat-templates-0.8.6-128.el7ost.noarch


How reproducible:

Deploy overcloud with two different environment files on top of each other.

Steps to Reproduce:
1. See above.
2.
3.

We need an fix to Heat DB to make sure when we run the update next time, it will not try to recreate the networks and will allow us to complete the update.

Thank you.