update subnet fails when no-host-route option is set

[Huang Cheng]

[root@controller ~]# openstack subnet set psn1 --no-host-route
HttpException: Bad Request (HTTP 400) (Request-ID: req-093e1224-4146-4f07-921d-73fbde138456), Invalid input for host_routes. Reason: Invalid data format for hostroute: ''.

error in neutron-server:
2018-02-03 09:45:48.529 29218 DEBUG neutron_lib.api.validators [req-093e1224-4146-4f07-921d-73fbde138456 7d40a908cdec477ead0381c28de4c796 06
8a4a1597714916bcf79fed09767f3b - default default] Invalid data format for hostroute: '' validate_hostroutes /usr/lib/python2.7/site-packages
/neutron_lib/api/validators/__init__.py:580
2018-02-03 09:45:48.529 29218 INFO neutron.pecan_wsgi.hooks.translation [req-093e1224-4146-4f07-921d-73fbde138456 7d40a908cdec477ead0381c28d
e4c796 068a4a1597714916bcf79fed09767f3b - default default] PUT failed (client error): Invalid input for host_routes. Reason: Invalid data fo
rmat for hostroute: ''.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/540568

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/python-openstackclient 3.16.0 release.

[Alexey Stupnikov (astupnikov)]

Faced this bug in Queens, cherry-picked the patch to stable/queens:

https://review.opendev.org/#/c/659545/

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/python-openstackclient queens-eol release.