neutron net-list with pagination fails on too many subnets

[Mykola Yakovliev]

To reproduce the bug you need to have a lot of subnets:

8192 (max uri length) / 40 (length of single subnet filter) = 204 subnets

In this situation when the count of subnets is over this value, the client will try to paginate request but fails because it does not count for a marker.

for i in `seq 1 254`; do neutron net-create test-net-$i ;done
for i in `seq 1 254`; do neutron subnet-create --name test-subnet-$i test-net-$i 172.25.$i.0/24;done

During "neutron net-list" call you will get an exception:

ERROR: neutronclient.shell An unknown exception occurred.
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/neutronclient/shell.py", line 787, in run_subcommand
    return run_command(cmd, cmd_parser, sub_argv)
  File "/usr/lib/python2.7/dist-packages/neutronclient/shell.py", line 104, in run_command
    return cmd.run(known_args)
  File "/usr/lib/python2.7/dist-packages/neutronclient/common/command.py", line 29, in run
    return super(OpenStackCommand, self).run(parsed_args)
  File "/usr/lib/python2.7/dist-packages/cliff/display.py", line 91, in run
    column_names, data = self.take_action(parsed_args)
  File "/usr/lib/python2.7/dist-packages/neutronclient/common/command.py", line 35, in take_action
    return self.get_data(parsed_args)
  File "/usr/lib/python2.7/dist-packages/neutronclient/neutron/v2_0/__init__.py", line 694, in get_data
    self.extend_list(data, parsed_args)
  File "/usr/lib/python2.7/dist-packages/neutronclient/neutron/v2_0/network.py", line 87, in extend_list
    _get_subnet_list(subnet_ids[i: i + chunk_size]))
  File "/usr/lib/python2.7/dist-packages/neutronclient/neutron/v2_0/network.py", line 61, in _get_subnet_list
    **search_opts).get('subnets', [])
  File "/usr/lib/python2.7/dist-packages/neutronclient/v2_0/client.py", line 96, in with_params
    ret = self.function(instance, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/neutronclient/v2_0/client.py", line 589, in list_subnets
    **_params)
  File "/usr/lib/python2.7/dist-packages/neutronclient/v2_0/client.py", line 301, in list
    for r in self._pagination(collection, path, **params):
  File "/usr/lib/python2.7/dist-packages/neutronclient/v2_0/client.py", line 314, in _pagination
    res = self.get(path, params=params)
  File "/usr/lib/python2.7/dist-packages/neutronclient/v2_0/client.py", line 287, in get
    headers=headers, params=params)
  File "/usr/lib/python2.7/dist-packages/neutronclient/v2_0/client.py", line 264, in retry_request
    headers=headers, params=params)
  File "/usr/lib/python2.7/dist-packages/neutronclient/v2_0/client.py", line 194, in do_request
    content_type=self.content_type())
  File "/usr/lib/python2.7/dist-packages/neutronclient/client.py", line 305, in do_request
    self._check_uri_length(url)
  File "/usr/lib/python2.7/dist-packages/neutronclient/client.py", line 301, in _check_uri_length
    excess=uri_len - MAX_URI_LEN)
RequestURITooLong: An unknown exception occurred.

The problem happens because subnet pagination does not take in a count "&marker=uuid".

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/573821

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/573821
Committed: https://git.openstack.org/cgit/openstack/python-neutronclient/commit/?id=0aefe1ccba63faa0d0e7131bbbd3331741e3ec2e
Submitter: Zuul
Branch: master

commit 0aefe1ccba63faa0d0e7131bbbd3331741e3ec2e
Author: Mykola Yakovliev <email address hidden>
Date: Fri Jun 8 14:35:36 2018 -0500

    Ensure API calls for subnets are in URL length limit

    Fix situation when with pagination enabled, neutronclient failed
    to read subnets information due to too long URI.

    Change-Id: I53240c536d77a95510b5c83b81e21782f29d886a
    Closes-Bug: 1775922

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/python-neutronclient 6.10.0 release.