Nova's fault wrap hiding real error status code from Neutron (and maybe others)

[Justin Hammond]

As a user I expect something that would produce a 404 to return a 404. Such as:

$ nova net-delete some_garbage

REQ: curl -i 'http://127.0.0.1:8774/v2/4eb9fda29831446cbfd22ab82a901284/os-tenant-networks/asdfasdfasdf' -X DELETE -H "Accept: application/json" -H "User-Agent: python-novaclient" -H "X-Auth-Project-Id: demo" -H "X-Auth-Token: {SHA1}c7b9ac5b9d6c88abd70694db6cbb175c223f988a"
RESP: [500] CaseInsensitiveDict({'date': 'Thu, 17 Jul 2014 18:00:59 GMT', 'content-length': '128', 'content-type': 'application/json; charset=UTF-8', 'x-compute-request-id': 'req-9f02f305-c01d-462c-abd4-0f9a283d992f'})
RESP BODY: {"computeFault": {"message": "The server has either erred or is incapable of performing the requested operation.", "code": 500}}

DEBUG (shell:802) The server has either erred or is incapable of performing the requested operation. (HTTP 500) (Request-ID: req-9f02f305-c01d-462c-abd4-0f9a283d992f)
Traceback (most recent call last):
  File "/opt/stack/python-novaclient/novaclient/shell.py", line 799, in main
    OpenStackComputeShell().main(argv)
  File "/opt/stack/python-novaclient/novaclient/shell.py", line 729, in main
    args.func(self.cs, args)
  File "/opt/stack/python-novaclient/novaclient/v1_1/contrib/tenant_networks.py", line 78, in do_net_delete
    cs.tenant_networks.delete(args.network_id)
  File "/opt/stack/python-novaclient/novaclient/v1_1/contrib/tenant_networks.py", line 36, in delete
    self._delete('/os-tenant-networks/%s' % base.getid(network))
  File "/opt/stack/python-novaclient/novaclient/base.py", line 109, in _delete
    _resp, _body = self.api.client.delete(url)
  File "/opt/stack/python-novaclient/novaclient/client.py", line 491, in delete
    return self._cs_request(url, 'DELETE', **kwargs)
  File "/opt/stack/python-novaclient/novaclient/client.py", line 459, in _cs_request
    **kwargs)
  File "/opt/stack/python-novaclient/novaclient/client.py", line 441, in _time_request
    resp, body = self.request(url, method, **kwargs)
  File "/opt/stack/python-novaclient/novaclient/client.py", line 435, in request
    raise exceptions.from_response(resp, body, url, method)
InternalServerError: The server has either erred or is incapable of performing the requested operation. (HTTP 500) (Request-ID: req-9f02f305-c01d-462c-abd4-0f9a283d992f)
ERROR (InternalServerError): The server has either erred or is incapable of performing the requested operation. (HTTP 500) (Request-ID: req-9f02f305-c01d-462c-abd4-0f9a283d992f)

When it is not implemented that makes sense. On my cloud installation I also receive this from neutron:

2014-07-14 16:39:08.200 29740 INFO neutron.wsgi [-] 10.23.245.95,10.13.143.233 - - [14/Jul/2014 16:39:08] "DELETE /v2.0/networks/jlh_delete_me.json HTTP/1.1"
404 176 0.010104

I believe nova.api.openstack.FaultWrapper is messing up the return from Neutron and showing the user a 500 (the default response to exceptions) instead of the expected 404.

[Thang Pham (thang-pham)]

I tried this on my devstack environment, with neutron as my networking service, and got:

$ nova net-delete <uuid>
ERROR (ClientException): The server has either erred or is incapable of performing the requested operation. (HTTP 500) (Request-ID: req-a7c2f648-9d1e-41cb-b55f-bb9fdea303a0)

Trace:
2014-08-12 10:43:27.597 21183 TRACE nova.api.openstack File "/opt/stack/nova/nova/api/openstack/compute/contrib/os_tenant_networks.py", line 135, in delete
2014-08-12 10:43:27.597 21183 TRACE nova.api.openstack self.network_api.delete(context, id)
2014-08-12 10:43:27.597 21183 TRACE nova.api.openstack File "/opt/stack/nova/nova/network/neutronv2/api.py", line 872, in delete
2014-08-12 10:43:27.597 21183 TRACE nova.api.openstack raise NotImplementedError()
2014-08-12 10:43:27.597 21183 TRACE nova.api.openstack NotImplementedError

The error (HTTP500) appears correct. Looking at the code, nova/network/neutronv2/api.py, delete() is raising a NotImplementedError exception. I am not sure why that part of the code is left unimplemented, but using the neutron CLI works fine.

[Sean Dague (sdague)]

While I'm not sure when it changed:

nova net-delete some_garbage now seems to do the right thing on Juno.

os1:~> nova net-delete some_garbage
ERROR (NotFound): Network not found (HTTP 404) (Request-ID: req-5b97d675-7d9c-48c7-9462-d6c06e28ab61)