Neutron-LBaaS v2: Providing invalid subnet_id to add member causing LB to go into pending_update indefinitely

[Franklin Naval]

1. Create Load Balancer
2. Create Listener
3. Create Pool
4. Add member to Pool with a subnet_id that does not exist (but has a valid uuid format)
5. Check Load Balancer provisioning_status

Result: Load Balancer stays in provisioning_status PENDING_UPDATE for more than 10 minutes.

Expected: Load Balancer should give an error that the subnet_id does not exist.

[Elena Ezhova (eezhova)]

Neutronclient validates that subnet exists [1] before sending request to neutron server so attempt to add a member with a non-existent subnet_id leads to an error:

dev-user@eezhova-devstack-2:~/devstack$ neutron lbaas-member-create --subnet d5709bff-b2fe-4df3-85ad-5a350a130e98 --address 10.0.0.6 --protocol-port 80 pool1
Unable to find subnet with name or id 'd5709bff-b2fe-4df3-85ad-5a350a130e98'
dev-user@eezhova-devstack-2:~/devstack$ neutron lbaas-loadbalancer-show lb1
+---------------------+------------------------------------------------+
| Field | Value |
+---------------------+------------------------------------------------+
| admin_state_up | True |
| description | |
| id | 47f878fe-2e3b-4f2d-9c61-a5a2f8d82c51 |
| listeners | {"id": "f2e4c75c-fd56-4cfd-9b6f-37f12ca62f1a"} |
| name | lb1 |
| operating_status | ONLINE |
| pools | {"id": "e5cc91a3-bb50-45c7-ba5a-928d19ea0dca"} |
| provider | octavia |
| provisioning_status | ACTIVE |
| tenant_id | 28d5aad6535e4ba09ba613b1d656f667 |
| vip_address | 10.0.0.3 |
| vip_port_id | 1af6a5cf-7198-4c56-a656-dfe7cb007b9b |
| vip_subnet_id | d5709bff-b2fe-4df3-85ad-5a350a130e90 |
+---------------------+------------------------------------------------+

Could you please provide more info on how this can be reproduced?

[1] https://github.com/openstack/python-neutronclient/blob/master/neutronclient/neutron/v2_0/lb/v2/member.py#L112-L113

[Elena Ezhova (eezhova)]

At the same time it is incorrect to have validation only on CLI level, validation should also be added to server code.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/310490

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/310490
Committed: https://git.openstack.org/cgit/openstack/neutron-lbaas/commit/?id=0ec8c1c29bec9cda5f1ebb2f843b935715dc93e0
Submitter: Jenkins
Branch: master

commit 0ec8c1c29bec9cda5f1ebb2f843b935715dc93e0
Author: Elena Ezhova <email address hidden>
Date: Wed Apr 27 17:25:02 2016 +0300

    Validate that subnet exists before adding member to pool

    Providing nonexistent subnet_id on pool member create leads
    to LB getting stuck in PENDING_UPDATE state. subnet_id is validated
    in neutronclient only on CLI level, so this problem takes place
    for all API calls.

    Change-Id: I9c9f790b6661cc7b15a8883bb5b7e45e69898d99
    Closes-Bug: #1573828

[Doug Hellmann (doug-hellmann)]

This issue was fixed in the openstack/neutron-lbaas 9.0.0.0b2 development milestone.