Created attachment 1376235 [details]
ovirt-provider-ovn.log

Description of problem:
When creating OVN router, OVN network, OVN subnet attached to the OVN network, and adding router interface by subnet, if the router is deleted, it is impossible remove the subnet using the provider. Provider error is logged: "Unable to delete subnet <SUBNET_ID> because it is connected to router <ROUTER_ID>. Please disconnect the subnet from the router first."

Version-Release number of selected component (if applicable):
ovirt-provider-ovn-1.2.2-1.el7ev.noarch

How reproducible:
100%

Steps to Reproduce:
1. Create OVN network:
{
    "network": {
        "name": "test_network",
        "admin_state_up": true
    }
}

NOTE network_id in response.

2. Create OVN subnet and attach it to the OVN network:
{
    "subnet": {
        "name": "test_subnet",
        "network_id": "<OVN_NET_ID>",
        "ip_version": 4,
        "cidr": "<CIDR>/24",
        "gateway_ip": "<CIDR_GW>"
    }
}

NOTE subnet_id in response.

3. Create OVN router:
{
    "router": {
        "name": "test_router",
        "admin_state_up": true
    }
}

NOTE router_id in response.

4. Create interface router by subnet:
{
    "subnet_id": "<OVN_SUBNET_ID>"
}

5. Delete the router:
DELETE on https://<SERVER>:9696/v2.0/routers/<OVN_ROUTER_ID>

6. Try to delete the subnet:
DELETE on https://<SERVER>:9696/v2.0/subnets/<OVN_SUBNET_ID>
{
  "error": {
    "message": "Unable to delete subnet <SUBNET_ID> because it is connected to router <ROUTER_ID. Please disconnect the subnet from the router first.",
    "code": 400,
    "title": "Bad Request"
  }
}

Actual results:
You cannot remove the subnet from the provider using API requests, only by using OVN commands.

Expected results:
All interfaces of a router should be removed once the router is deleted.

Additional info: