Open Stack

Hi,

After updating a quantum attribute, I'm looking for a way to "clear"
the field dns_nameservers

+------------------+-------------------------------------------------------+
| Field            | Value                                                 |
+------------------+-------------------------------------------------------+
| allocation_pools | {"start": "192.168.123.50", "end": "192.168.123.254"} |
| cidr             | 192.168.123.0/24                                      |
| dns_nameservers  |                                                       |
| enable_dhcp      | True                                                  |
| gateway_ip       | 192.168.123.49                                        |
| host_routes      |                                                       |
| id               | 336674e1-eded-4e5b-a87c-744281bab14b                  |
| ip_version       | 4                                                     |
| name             | fixed                                                 |
| network_id       | f6dd957c-3079-499d-a6bb-b34e278b23a6                  |
| tenant_id        | d765841b7e9b450a8d0d91f3b1189ded                      |
+------------------+-------------------------------------------------------+
:~ # neutron subnet-update fixed --dns_nameservers list=true 8.8.8.7 8.8.8.8
Updated subnet: fixed
:~ # neutron subnet-show fixed
+------------------+-------------------------------------------------------+
| Field            | Value                                                 |
+------------------+-------------------------------------------------------+
| allocation_pools | {"start": "192.168.123.50", "end": "192.168.123.254"} |
| cidr             | 192.168.123.0/24                                      |
| dns_nameservers  | 8.8.8.7                                               |
|                  | 8.8.8.8                                               |
| enable_dhcp      | True                                                  |
| gateway_ip       | 192.168.123.49                                        |
| host_routes      |                                                       |
| id               | 336674e1-eded-4e5b-a87c-744281bab14b                  |
| ip_version       | 4                                                     |
| name             | fixed                                                 |
| network_id       | f6dd957c-3079-499d-a6bb-b34e278b23a6                  |
| tenant_id        | d765841b7e9b450a8d0d91f3b1189ded                      |
+------------------+-------------------------------------------------------+


:~ # neutron subnet-update fixed --dns_nameservers list=false
Invalid input for dns_nameservers. Reason: Invalid data format for
nameserver: 'list=false'.

:~ # neutron subnet-update fixed --dns_nameservers
Invalid input for dns_nameservers. Reason: Invalid data format for
nameserver: 'True'.

:~ # neutron subnet-update fixed --dns_nameservers list=false 8.8.8.7 8.8.8.8
Invalid input for dns_nameservers. Reason: 'list=false' is not a valid
nameserver.

:~ # quantum subnet-update fixed --dns_nameservers list=false ""
Invalid input for dns_nameservers. Reason: 'list=false' is not a valid
nameserver.

:~ # neutron subnet-update fixed --dns-nameservers ""
Invalid input for dns_nameservers. Reason: Invalid data format for
nameserver: ''.

Any idea how can I clear this field?

Thanks,
Alejandro