auto-allocate related v2 jobs failures

probably due to Id2db458f4688e4aa4c70ccdb09867b9a66de28ea

eg. http://logs.openstack.org/05/458305/1/check/gate-tempest-dsvm-networking-midonet-v2-ubuntu-xenial/a5f0813/logs/testr_results.html.gz

ft1.2: neutron.tests.tempest.api.test_auto_allocated_topology.TestAutoAllocatedTopology.test_get_allocated_net_topology_as_tenant[id-64bc0b02-cee4-11e5-9f3c-080027605a2b]_StringException: Empty attachments:
  stderr
  stdout

pythonlogging:'': {{{
2017-04-20 03:01:36,913 13056 INFO [tempest.lib.common.rest_client] Request (TestAutoAllocatedTopology:test_get_allocated_net_topology_as_tenant): 200 GET http://10.35.62.156:9696/v2.0/networks?admin_state_up=True 0.136s
2017-04-20 03:01:36,913 13056 DEBUG [tempest.lib.common.rest_client] Request - Headers: {'Content-Type': 'application/json', 'Accept': 'application/json', 'X-Auth-Token': '<omitted>'}
        Body: None
    Response - Headers: {'status': '200', u'connection': 'close', 'content-location': 'http://10.35.62.156:9696/v2.0/networks?admin_state_up=True', u'content-type': 'application/json', u'x-openstack-request-id': 'req-c1067813-b061-4d9e-96ab-70359fbb4f0f', u'date': 'Thu, 20 Apr 2017 03:01:36 GMT', u'content-length': '510'}
        Body: {"networks":[{"status":"ACTIVE","subnets":["6a592e06-0557-42f9-bd12-2e53df9fe756","bcce1169-7c5f-48d5-aaf6-1b48b768d386"],"name":"public","admin_state_up":true,"tenant_id":"d0f5742ccab84035a0ee67a3e25a3c24","created_at":"2017-04-20T02:49:31Z","tags":[],"updated_at":"2017-04-20T03:01:36Z","is_default":false,"router:external":true,"revision_number":8,"shared":false,"port_security_enabled":true,"project_id":"d0f5742ccab84035a0ee67a3e25a3c24","id":"b02dacde-d6ff-4d7e-b6b8-9b425f0db6e2","description":"gman"}]}
2017-04-20 03:01:36,960 13056 INFO [tempest.lib.common.rest_client] Request (TestAutoAllocatedTopology:test_get_allocated_net_topology_as_tenant): 200 GET http://10.35.62.156:9696/v2.0/subnets?admin_state_up=True 0.046s
2017-04-20 03:01:36,960 13056 DEBUG [tempest.lib.common.rest_client] Request - Headers: {'Content-Type': 'application/json', 'Accept': 'application/json', 'X-Auth-Token': '<omitted>'}
        Body: None
    Response - Headers: {'status': '200', u'connection': 'close', 'content-location': 'http://10.35.62.156:9696/v2.0/subnets?admin_state_up=True', u'content-type': 'application/json', u'x-openstack-request-id': 'req-f88f9ed9-d5c3-4df5-9ec2-af7d1d67332d', u'date': 'Thu, 20 Apr 2017 03:01:36 GMT', u'content-length': '14'}
        Body: {"subnets":[]}
2017-04-20 03:01:37,031 13056 INFO [tempest.lib.common.rest_client] Request (TestAutoAllocatedTopology:test_get_allocated_net_topology_as_tenant): 200 GET http://10.35.62.156:9696/v2.0/routers?admin_state_up=True 0.070s
2017-04-20 03:01:37,031 13056 DEBUG [tempest.lib.common.rest_client] Request - Headers: {'Content-Type': 'application/json', 'Accept': 'application/json', 'X-Auth-Token': '<omitted>'}
        Body: None
    Response - Headers: {'status': '200', u'connection': 'close', 'content-location': 'http://10.35.62.156:9696/v2.0/routers?admin_state_up=True', u'content-type': 'application/json', u'x-openstack-request-id': 'req-ab0a411a-d97d-4ffb-a456-e6f6ec04e6d1', u'date': 'Thu, 20 Apr 2017 03:01:37 GMT', u'content-length': '15'}
        Body: {"routers": []}
2017-04-20 03:01:37,064 13056 INFO [tempest.lib.common.rest_client] Request (TestAutoAllocatedTopology:test_get_allocated_net_topology_as_tenant): 409 GET http://10.35.62.156:9696/v2.0/auto-allocated-topology/None 0.032s
2017-04-20 03:01:37,064 13056 DEBUG [tempest.lib.common.rest_client] Request - Headers: {'Content-Type': 'application/json', 'Accept': 'application/json', 'X-Auth-Token': '<omitted>'}
        Body: None
    Response - Headers: {'status': '409', u'connection': 'close', 'content-location': 'http://10.35.62.156:9696/v2.0/auto-allocated-topology/None', u'content-type': 'application/json', u'x-openstack-request-id': 'req-239c6fdb-8399-4233-b605-823afa6531ad', u'date': 'Thu, 20 Apr 2017 03:01:37 GMT', u'content-length': '133'}
        Body: {"NeutronError": {"message": "Deployment error: No default router:external network.", "type": "AutoAllocationFailure", "detail": ""}}
}}}

Traceback (most recent call last):
  File "/opt/stack/new/neutron/neutron/tests/tempest/api/test_auto_allocated_topology.py", line 91, in test_get_allocated_net_topology_as_tenant
    body = self.client.get_auto_allocated_topology()
  File "/opt/stack/new/neutron/neutron/tests/tempest/services/network/json/network_client.py", line 802, in get_auto_allocated_topology
    resp, body = self.get(uri)
  File "tempest/lib/common/rest_client.py", line 292, in get
    return self.request('GET', url, extra_headers, headers)
  File "tempest/lib/common/rest_client.py", line 666, in request
    self._error_checker(resp, resp_body)
  File "tempest/lib/common/rest_client.py", line 787, in _error_checker
    raise exceptions.Conflict(resp_body, resp=resp)
tempest.lib.exceptions.Conflict: An object with that identifier already exists
Details: {u'type': u'AutoAllocationFailure', u'detail': u'', u'message': u'Deployment error: No default router:external network.'}