Neutron Lib

3.25.0 verified Mon Apr 27 auth: no python

neutron-lib is a library of shared routines and utilities for OpenStack Neutron. It provides common code (exceptions, DB models, API definitions, extensions) used by neutron and neutron sub-projects. Version 3.25.0 supports Python >=3.10. Release cadence follows OpenStack coordinated releases, often with multiple minor releases per cycle.

pip install neutron-lib

Common errors

error ImportError: cannot import name 'NeutronException' from 'neutron_lib' ↓

cause NeutronException is in neutron_lib.exceptions, not directly in neutron_lib.

fix

Use: from neutron_lib import exceptions try: raise exceptions.NeutronException(...)

error AttributeError: module 'neutron_lib' has no attribute 'context' ↓

cause Common mistake: trying to use 'neutron_lib.context' but context module is not automatically imported. You need an explicit import.

fix

Add: from neutron_lib import context

error neutron_lib.exceptions.NeutronException: Object not found ↓

cause This error is raised when a resource is not found (like a port, network, etc.) but the caller may not realize it's an exception from neutron-lib.

fix

Catch neutron_lib.exceptions.NeutronException or a more specific subclass like PortNotFound, NetworkNotFound.

Warnings

breaking In neutron-lib >= 2.0.0, the DB model classes were moved into separate database backend modules. Direct imports from neutron_lib.db.model_base may be deprecated or changed. ↓

fix If using neutron_lib.db.model_base, check the OpenStack release notes for the exact new import path, e.g., from neutron_lib.db import model_base as mb.

breaking The api.attributes module was refactored in some versions; constants like ATTR_NOT_SPECIFIED were moved to neutron_lib.api.definitions. ↓

fix Use from neutron_lib.api.definitions import ATTR_NOT_SPECIFIED instead.

gotcha Do not install both neutron and neutron-lib from different versions in the same environment. They must be from the same OpenStack release series to avoid API incompatibility. ↓

fix Ensure that the versions of neutron and neutron-lib are consistent (e.g., both from the same OpenStack release).

Imports

context
wrong
```
from neutron import context
```
correct
```
from neutron_lib import context
```
neutron-lib was extracted from neutron; direct imports from 'neutron' may break.
exceptions
wrong
```
from neutron.common import exceptions
```
correct
```
from neutron_lib import exceptions
```
Old path from monolithic neutron; use neutron_lib.exceptions.

Quickstart

Creates a RequestContext and demonstrates using exceptions.

from neutron_lib import context
from neutron_lib import exceptions

# Create a request context
req_context = context.RequestContext(user_id='admin',
                                      tenant_id='admin',
                                      roles=['admin'])
print(req_context.to_dict())

# Raise a NeutronException
try:
    raise exceptions.NeutronException(message='example')
except exceptions.NeutronException as e:
    print(e)