Bug 1651805

Description of problem:

  Currently users can easily destroy their overcloud by running a deploy without original environment files. Specifically network environment files. If a deploy has isolated networks and a subsequent deploy,scale,update is ran without all the original network environment files then the overcloud can be destroyed. This happens because without the network environment files that specify isolated networks, the deployment will put everything on controlplane and attempt to delete isolated networks.
  This problem can also occur if users are using a script to deploy and add a new line to the script without the \ . This will cause the script not to use any environment files after the mistake. Given all these scenerios are user mistakes , we need to make sure it's not so easy to destroy an environment. 



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

How reproducible:
unknown

Steps to Reproduce:
1.deploy overcloud with isolated networks
2.re-run deploy command without network environmetn files
3.

Actual results:
overcloud destroyed

Expected results:
Warning message or something to alert users they need to include original deployment network environment files
Additional info:

Currently the only safegaurd against this is the fact that once the deployment attempts to delete the overcloud networks it can not since there are still neutron ports on the network. So deploy fails with unable to delete netork errors such as:
[overcloud-Networks-impwtkh5lxyq-ExternalNetwork-3373wgx7a2nm]: DELETE_FAILED  Resource DELETE failed: Conflict: resources.ExternalSubnet: Unable to complete operation on subnet f2972d18-95a8-43c7-aa98-8f1e5250dab3: One or more ports have an IP allocation from this subnet.

UPDATE_FAILED  resources.Networks: Conflict: 
resources.InternalNetwork.resources.InternalApiSubnet: Unable to complete operation on subnet 8c4ba2d9-cbb1-4398-a024-c405a16daf3a: One or more ports have an IP allocation from this subnet.