get_interfaces: don't exclude Open vSwitch bridge/bond members (#608)

If an OVS bridge was used as the only/primary interface, the 'init'
stage failed with a "Not all expected physical devices present" error,
leaving the system with a broken SSH setup.

LP: #1898997

2 files changed, 48 insertions, 3 deletions

diff --git a/cloudinit/net/__init__.py b/cloudinit/net/__init__.py
index 75e79ca8..de65e7af 100644
--- a/cloudinit/net/__init__.py
+++ b/cloudinit/net/__init__.py
@@ -124,6 +124,15 @@ def master_is_bridge_or_bond(devname):
     return (os.path.exists(bonding_path) or os.path.exists(bridge_path))
 
 
+def master_is_openvswitch(devname):
+    """Return a bool indicating if devname's master is openvswitch"""
+    master_path = get_master(devname)
+    if master_path is None:
+        return False
+    ovs_path = sys_dev_path(devname, path="upper_ovs-system")
+    return os.path.exists(ovs_path)
+
+
 def is_netfailover(devname, driver=None):
     """ netfailover driver uses 3 nics, master, primary and standby.
         this returns True if the device is either the primary or standby
@@ -862,8 +871,10 @@ def get_interfaces(blacklist_drivers=None) -> list:
             continue
         if is_bond(name):
             continue
-        if get_master(name) is not None and not master_is_bridge_or_bond(name):
-            continue
+        if get_master(name) is not None:
+            if (not master_is_bridge_or_bond(name) and
+                    not master_is_openvswitch(name)):
+                continue
         if is_netfailover(name):
             continue
         mac = get_interface_mac(name)
diff --git a/cloudinit/net/tests/test_init.py b/cloudinit/net/tests/test_init.py
index 311ab6f8..0535387a 100644
--- a/cloudinit/net/tests/test_init.py
+++ b/cloudinit/net/tests/test_init.py
@@ -190,6 +190,28 @@ class TestReadSysNet(CiTestCase):
         self.assertTrue(net.master_is_bridge_or_bond('eth1'))
         self.assertTrue(net.master_is_bridge_or_bond('eth2'))
 
+    def test_master_is_openvswitch(self):
+        ovs_mac = 'bb:cc:aa:bb:cc:aa'
+
+        # No master => False
+        write_file(os.path.join(self.sysdir, 'eth1', 'address'), ovs_mac)
+
+        self.assertFalse(net.master_is_bridge_or_bond('eth1'))
+
+        # masters without ovs-system => False
+        write_file(os.path.join(self.sysdir, 'ovs-system', 'address'), ovs_mac)
+
+        os.symlink('../ovs-system', os.path.join(self.sysdir, 'eth1',
+                   'master'))
+
+        self.assertFalse(net.master_is_openvswitch('eth1'))
+
+        # masters with ovs-system => True
+        os.symlink('../ovs-system', os.path.join(self.sysdir, 'eth1',
+                   'upper_ovs-system'))
+
+        self.assertTrue(net.master_is_openvswitch('eth1'))
+
     def test_is_vlan(self):
         """is_vlan is True when /sys/net/devname/uevent has DEVTYPE=vlan."""
         ensure_file(os.path.join(self.sysdir, 'eth0', 'uevent'))
@@ -465,20 +487,32 @@ class TestGetInterfaceMAC(CiTestCase):
     ):
         bridge_mac = 'aa:bb:cc:aa:bb:cc'
         bond_mac = 'cc:bb:aa:cc:bb:aa'
+        ovs_mac = 'bb:cc:aa:bb:cc:aa'
+
         write_file(os.path.join(self.sysdir, 'br0', 'address'), bridge_mac)
         write_file(os.path.join(self.sysdir, 'br0', 'bridge'), '')
 
         write_file(os.path.join(self.sysdir, 'bond0', 'address'), bond_mac)
         write_file(os.path.join(self.sysdir, 'bond0', 'bonding'), '')
 
+        write_file(os.path.join(self.sysdir, 'ovs-system', 'address'),
+                   ovs_mac)
+
         write_file(os.path.join(self.sysdir, 'eth1', 'address'), bridge_mac)
         os.symlink('../br0', os.path.join(self.sysdir, 'eth1', 'master'))
 
         write_file(os.path.join(self.sysdir, 'eth2', 'address'), bond_mac)
         os.symlink('../bond0', os.path.join(self.sysdir, 'eth2', 'master'))
 
+        write_file(os.path.join(self.sysdir, 'eth3', 'address'), ovs_mac)
+        os.symlink('../ovs-system', os.path.join(self.sysdir, 'eth3',
+                   'master'))
+        os.symlink('../ovs-system', os.path.join(self.sysdir, 'eth3',
+                   'upper_ovs-system'))
+
         interface_names = [interface[0] for interface in net.get_interfaces()]
-        self.assertEqual(['eth1', 'eth2'], sorted(interface_names))
+        self.assertEqual(['eth1', 'eth2', 'eth3', 'ovs-system'],
+                         sorted(interface_names))
 
 
 class TestInterfaceHasOwnMAC(CiTestCase):