From bc14d3a708be078e03b64e96b9a8daaa3b6909d2 Mon Sep 17 00:00:00 2001
From: James Falcon <therealfalcon@gmail.com>
Date: Fri, 21 Aug 2020 16:21:37 -0500
Subject: [PATCH] Azure: Add netplan driver filter when using hv_netvsc driver

This fixes a long delay during boot of some instances. For Azure instance types using SR-IOV via the Hyper-V netvsc network driver, two network interfaces are created that share the same MAC, but only the virtual device should be configured and used. Updating the netplan configuration to filter on the hv_netvsc driver prevents netplan from trying to figure both devices.

LP: #1830740
---
 cloudinit/sources/DataSourceAzure.py          | 14 +++++++++++---
 tests/unittests/test_datasource/test_azure.py | 17 +++++++++++++++++
 2 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/cloudinit/sources/DataSourceAzure.py b/cloudinit/sources/DataSourceAzure.py
index f572a4efc03..86cc7c28b6c 100755
--- a/cloudinit/sources/DataSourceAzure.py
+++ b/cloudinit/sources/DataSourceAzure.py
@@ -18,6 +18,7 @@
 from cloudinit import log as logging
 from cloudinit import net
 from cloudinit.event import EventType
+from cloudinit.net import device_driver
 from cloudinit.net.dhcp import EphemeralDHCPv4
 from cloudinit import sources
 from cloudinit.sources.helpers import netlink
@@ -1387,9 +1388,16 @@ def parse_network_config(imds_metadata):
                                 ip=privateIp, prefix=netPrefix))
                 if dev_config:
                     mac = ':'.join(re.findall(r'..', intf['macAddress']))
-                    dev_config.update(
-                        {'match': {'macaddress': mac.lower()},
-                         'set-name': nicname})
+                    dev_config.update({
+                        'match': {'macaddress': mac.lower()},
+                        'set-name': nicname
+                    })
+                    # With netvsc, we can get two interfaces that
+                    # share the same MAC, so we need to make sure
+                    # our match condition also contains the driver
+                    driver = device_driver(nicname)
+                    if driver and driver == 'hv_netvsc':
+                        dev_config['match']['driver'] = driver
                     netconfig['ethernets'][nicname] = dev_config
             evt.description = "network config from imds"
         else:
diff --git a/tests/unittests/test_datasource/test_azure.py b/tests/unittests/test_datasource/test_azure.py
index 96bcc7a2a70..47e03bd1a74 100644
--- a/tests/unittests/test_datasource/test_azure.py
+++ b/tests/unittests/test_datasource/test_azure.py
@@ -278,6 +278,23 @@ def test_ipv6_secondary_ips_will_be_static_cidrs(self):
         }
         self.assertEqual(expected, dsaz.parse_network_config(imds_data))
 
+    @mock.patch('cloudinit.sources.DataSourceAzure.device_driver',
+                return_value='hv_netvsc')
+    def test_match_driver_for_netvsc(self, m_driver):
+        """parse_network_config emits driver when using netvsc."""
+        expected = {'ethernets': {
+            'eth0': {
+                'dhcp4': True,
+                'dhcp4-overrides': {'route-metric': 100},
+                'dhcp6': False,
+                'match': {
+                    'macaddress': '00:0d:3a:04:75:98',
+                    'driver': 'hv_netvsc',
+                },
+                'set-name': 'eth0'
+            }}, 'version': 2}
+        self.assertEqual(expected, dsaz.parse_network_config(NETWORK_METADATA))
+
 
 class TestGetMetadataFromIMDS(HttprettyTestCase):