python-neutronclient — Errors

Errors — python-neutronclient — branch stable/2026.2

Branch stable/2026.2 @ 596a9d99b188 (14.0.0 + 2 maintenance commits) — repository https://opendev.org/openstack/python-neutronclient — analysed on 2026-11-01

Every [observed] run is in [_rewrite/defect-repros_stable-2026.2.json](_rewrite/defect-repros_stable-2026.2.json), under the ID given in parentheses. The stub is not Neutron: these runs show how the client reacts to a given response, not that a real service sends it.

1. Exit codes

Some validation runs after parsing, and so exits 1, not 2: --source-port :5 (fc-create-port-empty), --branching-point a (graph-no-colon).

2. Exceptions of the Python library

All are in neutronclient/common/exceptions.py. The library has three groups, as the module docstring says (neutronclient/common/exceptions.py:20-31).

HTTP status → exception

exception_handler_v20 chooses the class in this order (neutronclient/v2_0/client.py:46-92):

1. if the body has NeutronError with type, message and detail: the class <type>Client in the exceptions module, if it exists;
2. otherwise the class for the status;
3. otherwise NeutronClientException.

status_code and request_ids are set on the instance, and the message ends with Neutron server returns request_ids: […] when the response has that header (neutronclient/common/exceptions.py:76-87).

NeutronError.type → exception

A compatible service must keep these type names, since the projects below catch these classes.

Projects can add to this list by monkey-patching the module: Manila adds PortBindingAlreadyExistsClient (manila:manila/network/neutron/api.py:80).

Exceptions raised by the library itself

AmbiguousEndpoints (neutronclient/common/exceptions.py:209) is never raised, and its template %(matching_endpoints) lacks the conversion type.

Error body → text

401: keystoneauth invalidates the token and retries once (keystoneauth1:keystoneauth1/session.py:1130). error-401-once exits 0 after two GET; error-401-always sends two GET and fails.

3. Messages of the commands

Generated from the code. CommandError here is osc_lib.exceptions.CommandError, unless stated otherwise.

The row "built at run time" covers: Protocol port value %s must be an integer or integer:integer. (neutronclient/osc/v2/sfc/sfc_flow_classifier.py:346), Error: Duplicate destination chains from source chain {} (neutronclient/osc/v2/sfc/sfc_service_graph.py:262), and Error: Source chain {} is in use already (neutronclient/osc/v2/sfc/sfc_service_graph.py:267).

Logged and not raised: Failed to delete … with name or ID '…': …, once per failed item, before the final count (neutronclient/osc/v2/logging/network_log.py:180, neutronclient/osc/v2/sfc/sfc_flow_classifier.py:169, neutronclient/osc/v2/sfc/sfc_port_chain.py:126, neutronclient/osc/v2/sfc/sfc_port_pair.py:122, neutronclient/osc/v2/sfc/sfc_port_pair_group.py:130, neutronclient/osc/v2/sfc/sfc_service_graph.py:142).

Logged on stderr by each of the 7 binding commands, at level warning, with exit 0 [observed: warning-on-python-binding]: The python binding code in neutronclient is deprecated in favor of OpenstackSDK, please use that as this will be removed in a future release. (neutronclient/v2_0/client.py:253).

4. Defects found

Only what was reproduced on the stub or read in the code. All pass the unit tests, because these mock the clients (neutronclient/tests/unit/osc/v2/fakes.py:27-30).

Not defects, but traps [observed]:

• network log create --project p with a 403 from Keystone sends the name as project_id (log-create-project-forbidden, neutronclient/osc/utils.py:113-116). This is deliberate, says the docstring.
• A catalog without network gives public endpoint for network service in RegionOne region not found on binding commands, and a longer SDK text on sfc commands (catalog-no-network-log, catalog-no-network-sfc). No crash.
• --port-pair-group-parameters foo=bar passes any key to the server (ppg-create-other-key).

5. Asynchronous errors

None. The process exits with the first failure, except for the loops in the delete commands. See 05.

Source: reverse-spec-python-neutronclient/02-errors_stable-2026.2.md. The _rewrite/ and _inventory/ files are not published on the site.