From 6cce41eaa3e73cad9d04255521634f1af08267b6 Mon Sep 17 00:00:00 2001
From: Adam Gandelman <adamg@ubuntu.com>
Date: Mon, 20 Jul 2015 15:44:23 -0700
Subject: [PATCH] Only work with ipv4 subnet metadata if one exists

This code currently throws an exception and fails the build if an
instance boots on a network without a v4 subnet.  Protect against
this by checking it has a ipv4 subnet.

Change-Id: I7c5de308b557293f5ac6b919d5566ace809ce200
Closes-bug: #1476402
---
 nova/tests/unit/network/test_network_info.py | 50 ++++++++++++++++++++
 nova/virt/netutils.py                        |  2 +-
 2 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/nova/tests/unit/network/test_network_info.py b/nova/tests/unit/network/test_network_info.py
index e779a5ee3871..7dc50ba3e79d 100644
--- a/nova/tests/unit/network/test_network_info.py
+++ b/nova/tests/unit/network/test_network_info.py
@@ -1140,3 +1140,53 @@ class TestNetworkMetadata(test.NoDBTestCase):
 
         network_json = netutils.get_network_metadata(self.netinfo)
         self.assertEqual(expected_json, network_json)
+
+    def test_get_network_metadata_no_ipv4(self):
+        expected_json = {
+            "services": [
+                {
+                    "type": "dns",
+                    "address": "1:2:3:4::"
+                },
+                {
+                    "type": "dns",
+                    "address": "2:3:4:5::"
+                }
+            ],
+            "networks": [
+                {
+                    "network_id": 1,
+                    "type": "ipv6",
+                    "netmask": "ffff:ffff:ffff::",
+                    "link": "interface0",
+                    "routes": [
+                        {
+                            "netmask": "::",
+                            "network": "::",
+                            "gateway": "fd00::1"
+                        },
+                        {
+                            "netmask": "ffff:ffff:ffff::",
+                            "network": "::",
+                            "gateway": "fd00::1:1"
+                        }
+                    ],
+                    "ip_address": "fd00::2",
+                    "id": "network0"
+                }
+            ],
+            "links": [
+                {
+                    "ethernet_mac_address": "aa:aa:aa:aa:aa:aa",
+                    "mtu": 1500,
+                    "type": "phy",
+                    "id": "interface0",
+                    "vif_id": 1
+                }
+            ]
+        }
+
+        # drop the ipv4 subnet
+        self.netinfo[0]['network']['subnets'].pop(0)
+        network_json = netutils.get_network_metadata(self.netinfo)
+        self.assertEqual(expected_json, network_json)
diff --git a/nova/virt/netutils.py b/nova/virt/netutils.py
index acefda9ddb5e..4a53f4a1ccf2 100644
--- a/nova/virt/netutils.py
+++ b/nova/virt/netutils.py
@@ -226,7 +226,7 @@ def get_network_metadata(network_info, use_ipv6=None):
             links.append(link)
 
         # Add IPv4 and IPv6 networks if they exist
-        if subnet_v4.get('ips'):
+        if subnet_v4 and subnet_v4.get('ips'):
             net_num += 1
             nets.append(_get_nets(vif, subnet_v4, 4, net_num, link['id']))
             services += [dns for dns in _get_dns_services(subnet_v4)