Subnet details page fails when a subnet uses IPv6 with prefix delegation

[Jorge]

Package: openstack-dashboard
Description: Ubuntu 16.04.2 LTS
Release: 16.04
openstack-dashboard:
  Installed: 2:9.1.2-0ubuntu1
  Candidate: 2:9.1.2-0ubuntu1

Description: problem occurs when using an IPv6 subnet with prefix delegation (IPv4 subnets are ok). When using web interface, if we try to see subnet details in menu System -> Networks -> Click on network name -> Click on subnet name we got the following error:

neutron-server[22658]: 2017-07-04 16:29:21.186 22864 INFO neutron.wsgi [req-0fbaad92-83ff-4179-8056-8521fbef5ff9 e85813733498d6d6b6678b77d4756aaddef55bba18166be7d3bc3a8d20a65fd8 769822d4bf984cfeb3ab910cec9fa5b3 - - -] 192.168.0.1 - - [04/Jul/2017 16:29:21] "GET /v2.0/subnetpools/prefix_delegation.json HTTP/1.1" 404 266 0.007587

The subnet is working fine. Here is the output of opentack CLI 'show' statement:

$ openstack subnet show nti-subnet-ipv6

+-------------------+-------------------------------------------------------------+
| Field | Value |
+-------------------+-------------------------------------------------------------+
| allocation_pools | 2001:DB8:1400:5026::2-2001:DB8:1400:5026:ffff:ffff:ffff:ffff|
| cidr | 2001:DB8:1400:5026::/64 |
| created_at | 2016-09-12T13:01:15 |
| description | |
| dns_nameservers | 2001:DB8:1400:2127::FFFE |
| enable_dhcp | True |
| gateway_ip | 2001:DB8:1400:5026::1 |
| host_routes | |
| id | 129bd534-7121-4759-93a2-68ac907edf74 |
| ip_version | 6 |
| ipv6_address_mode | dhcpv6-stateless |
| ipv6_ra_mode | dhcpv6-stateless |
| name | nti-subnet-ipv6 |
| network_id | d204d9a2-bb8a-48af-bfa0-f0438970d98b |
| project_id | 769822d4bf984cfeb3ab910cec9fa5b3 |
| subnetpool_id | prefix_delegation |
| updated_at | 2017-05-31T18:59:50 |
+-------------------+------------------------------------------------------------ +

Trying to find the problem, I found the file openstack_dashboard/dashboards/project/networks/subnets/views.py with this code (comments are mine):

class DetailView(tabs.TabView):
    tab_group_class = project_tabs.SubnetDetailTabs
    template_name = 'horizon/common/_detail.html'
    page_title = "{{ subnet.name|default:subnet.id }}"

    @memoized.memoized_method
    def get_data(self):
        subnet_id = self.kwargs['subnet_id']
        try:
            subnet = api.neutron.subnet_get(self.request, subnet_id)
        except Exception:
            subnet = []
            msg = _('Unable to retrieve subnet details.')
            exceptions.handle(self.request, msg,
                              redirect=self.get_redirect_url())
        else:
            if subnet.ip_version == 6:
                ipv6_modes = utils.get_ipv6_modes_menu_from_attrs(
                    subnet.ipv6_ra_mode, subnet.ipv6_address_mode)
                subnet.ipv6_modes_desc = utils.IPV6_MODE_MAP.get(ipv6_modes)

# if ('subnetpool_id' in subnet and
# subnet.subnetpool_id and
# api.neutron.is_extension_supported(self.request,
# 'subnet_allocation')):
# subnetpool = api.neutron.subnetpool_get(self.request,
# subnet.subnetpool_id)
# subnet.subnetpool_name = subnetpool.name

The commented code snippet seems to be the problem. It tries to get some information about the subnetpool. However, when a subnet uses IPv6 prefix delegation this is automatically setted when creating de subnet and if we try to read information about a subnetpool called "prefix_delegation" we get nothing (empty).

So, as showed, if I comment that code snippet the web interface succedds and show the subnet details.

I think it is necessary to correct something with this part of the code.

Thanks!

[Akihiro Motoki (amotoki)]

Yes, we need to add a special handling when subnetpool_id is 'prefix_delegation'. It is a special subnet pool and we cannot retrieve such subnetpool via the neutron API.

[Akihiro Motoki (amotoki)]

Note that 9.1.2 is a mitaka release of horizon. Mitaka is no longer maintained as the upstream, so the fix will be only in the master and pike release.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/510302

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/510302
Committed: https://git.openstack.org/cgit/openstack/horizon/commit/?id=5de6b3eb14e414364bc115225d6067e3a87ad0ac
Submitter: Zuul
Branch: master

commit 5de6b3eb14e414364bc115225d6067e3a87ad0ac
Author: Akihiro Motoki <email address hidden>
Date: Sat Oct 7 16:02:50 2017 +0000

    Show subnet detail with prefix_delegation subnetpool properly

    Subnet pool ID 'prefix_delegation' is a special subnet pool in Neutron
    and there is no real subnet pool with ID 'prefix_delegation',
    so we need to skip subnetpool_get() call
    if a subnet has 'prefix_delegation' subnet pool.

    This commit also adds unit tests which covers subnet pool operations
    in the subnet detail view.

    Change-Id: I3227a92084ee79b60d2b10262ed94a034e396306
    Closes-Bug: #1702466

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/horizon 13.0.0.0b1 development milestone.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/pike
Review: https://review.openstack.org/534359

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/534359
Committed: https://git.openstack.org/cgit/openstack/horizon/commit/?id=d60ea82bfc8cd1c2a576d201e3dfe1ce9a5f99b3
Submitter: Zuul
Branch: stable/pike

commit d60ea82bfc8cd1c2a576d201e3dfe1ce9a5f99b3
Author: Akihiro Motoki <email address hidden>
Date: Sat Oct 7 16:02:50 2017 +0000

    Show subnet detail with prefix_delegation subnetpool properly

    Subnet pool ID 'prefix_delegation' is a special subnet pool in Neutron
    and there is no real subnet pool with ID 'prefix_delegation',
    so we need to skip subnetpool_get() call
    if a subnet has 'prefix_delegation' subnet pool.

    This commit also adds unit tests which covers subnet pool operations
    in the subnet detail view.

    Change-Id: I3227a92084ee79b60d2b10262ed94a034e396306
    Closes-Bug: #1702466
    (cherry picked from commit 5de6b3eb14e414364bc115225d6067e3a87ad0ac)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/horizon 12.0.3 release.