Reviewed: https://review.opendev.org/c/openstack/neutron/+/753717 Committed: https://opendev.org/openstack/neutron/commit/f759915ab0c30ebba6d3d970943b596b5c245599 Submitter: "Zuul (22348)" Branch: master
commit f759915ab0c30ebba6d3d970943b596b5c245599 Author: Thomas Bachman <[email protected]> Date: Wed Sep 23 14:34:36 2020 +0000 Fix default value for MTUs, when not provided When networks are created using REST APIs, if the MTU isn't specified in the request, then a default value of 0 is used. Some use cases, such as the auto-allocated-topology workflow, call the plugin directly to create networks, bypassing the layer that inserts this default value. Commit 68625686a40b3eb75502c8116f23d2297e288ca1 introduced a different default value at the DB layer, defined by a constant in neutron-lib. If the maximum MTU size has been configured lower than this constant, then the user receives an exception, even though they didn't provide a value for MTU. This patch changes the default value used in the DB layer, so that it's consistent with the workflow seen via REST APIs. Change-Id: Ica21e891cd2559942abb0ab2b12132e7f6cdd835 Closes-Bug: #1896933 ** Changed in: neutron Status: In Progress => Fix Released -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to neutron. https://bugs.launchpad.net/bugs/1896933 Title: Exception when plugin creates a network without specifying the MTU Status in neutron: Fix Released Bug description: This was found as a UT regression failure in the x/group-based-policy project, but I think the same issue applies to the auto-allocated- topology workflow (or any feature that creates a network at the plugin or DB layer instead of at the REST layer). The exception seen is this: File "/home/zuul/src/opendev.org/x/group-based-policy/.tox/py36/lib/python3.6/site-packages/neutron/plugins/ml2/plugin.py", line 1053, in create_network result, mech_context = self._create_network_db(context, network) File "/home/zuul/src/opendev.org/x/group-based-policy/gbpservice/neutron/plugins/ml2plus/plugin.py", line 333, in _create_network_db context, network) File "/home/zuul/src/opendev.org/x/group-based-policy/.tox/py36/lib/python3.6/site-packages/neutron/plugins/ml2/plugin.py", line 1013, in _create_network_db net_db.mtu = self._get_network_mtu(net_db) File "/home/zuul/src/opendev.org/x/group-based-policy/.tox/py36/lib/python3.6/site-packages/neutron/plugins/ml2/plugin.py", line 995, in _get_network_mtu raise exc.InvalidInput(error_message=msg) neutron_lib.exceptions.InvalidInput: Invalid input for operation: Requested MTU is too big, maximum is 1000. The UT limits the network MTU using configuration file settings: https://opendev.org/x/group-based-policy/src/branch/master/gbpservice/neutron/tests/unit/services/grouppolicy/test_aim_mapping_driver.py#L2951-L2952 The regression happens because a default MTU for the DB layer was introduced in this patch: https://review.opendev.org/#/c/679399/ The default value used is the DEFAULT_NETWORK_MTU constant from neutron-lib (1500). This is different than the default value installed by the REST layer (0). When the network MTU is constrained using configuration files, it gets to this code path: https://opendev.org/openstack/neutron/src/branch/master/neutron/plugins/ml2/plugin.py#L992-L1002 Since the DB layer has set the default to 1500 instead of 0, this exception gets triggered, even though the caller at the plugin layer didn't specify a value for the MTU. One possible fix is to have the DB layer use a value of 0 for the default instead of DEFAULT_NETWORK_MTU. To manage notifications about this bug go to: https://bugs.launchpad.net/neutron/+bug/1896933/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : [email protected] Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp
