SmartOS: fix get_interfaces for nics that do not have addr_assign_type.

When attempting to apply network configuration for SmartOS's container
platform, cloud-init would not identify nics.  The nics on provided
in this container service do not have 'addr_assign_type'.  That
was being interpreted as being a "stolen" mac, and would be filtered
out by get_interfaces.

2 files changed, 46 insertions, 8 deletions

diff --git a/cloudinit/net/__init__.py b/cloudinit/net/__init__.py
index 43226bd0..3ffde52c 100644
--- a/cloudinit/net/__init__.py
+++ b/cloudinit/net/__init__.py
@@ -359,8 +359,12 @@ def interface_has_own_mac(ifname, strict=False):
       1: randomly generated   3: set using dev_set_mac_address"""
 
     assign_type = read_sys_net_int(ifname, "addr_assign_type")
-    if strict and assign_type is None:
-        raise ValueError("%s had no addr_assign_type.")
+    if assign_type is None:
+        # None is returned if this nic had no 'addr_assign_type' entry.
+        # if strict, raise an error, if not return True.
+        if strict:
+            raise ValueError("%s had no addr_assign_type.")
+        return True
     return assign_type in (0, 1, 3)
 
 
diff --git a/tests/unittests/test_net.py b/tests/unittests/test_net.py
index fac82678..31807e13 100644
--- a/tests/unittests/test_net.py
+++ b/tests/unittests/test_net.py
@@ -2,12 +2,9 @@
 
 from cloudinit import net
 from cloudinit.net import cmdline
-from cloudinit.net import eni
-from cloudinit.net import natural_sort_key
-from cloudinit.net import netplan
-from cloudinit.net import network_state
-from cloudinit.net import renderers
-from cloudinit.net import sysconfig
+from cloudinit.net import (
+    eni, interface_has_own_mac, natural_sort_key, netplan, network_state,
+    renderers, sysconfig)
 from cloudinit.sources.helpers import openstack
 from cloudinit import temp_utils
 from cloudinit import util
@@ -2691,6 +2688,43 @@ class TestGetInterfaces(CiTestCase):
             any_order=True)
 
 
+class TestInterfaceHasOwnMac(CiTestCase):
+    """Test interface_has_own_mac.  This is admittedly a bit whitebox."""
+
+    @mock.patch('cloudinit.net.read_sys_net_int', return_value=None)
+    def test_non_strict_with_no_addr_assign_type(self, m_read_sys_net_int):
+        """If nic does not have addr_assign_type, it is not "stolen".
+
+        SmartOS containers do not provide the addr_assign_type in /sys.
+
+            $ ( cd /sys/class/net/eth0/ && grep -r . *)
+            address:90:b8:d0:20:e1:b0
+            addr_len:6
+            flags:0x1043
+            ifindex:2
+            mtu:1500
+            tx_queue_len:1
+            type:1
+        """
+        self.assertTrue(interface_has_own_mac("eth0"))
+
+    @mock.patch('cloudinit.net.read_sys_net_int', return_value=None)
+    def test_strict_with_no_addr_assign_type_raises(self, m_read_sys_net_int):
+        with self.assertRaises(ValueError):
+            interface_has_own_mac("eth0", True)
+
+    @mock.patch('cloudinit.net.read_sys_net_int')
+    def test_expected_values(self, m_read_sys_net_int):
+        msg = "address_assign_type=%d said to not have own mac"
+        for address_assign_type in (0, 1, 3):
+            m_read_sys_net_int.return_value = address_assign_type
+            self.assertTrue(
+                interface_has_own_mac("eth0", msg % address_assign_type))
+
+        m_read_sys_net_int.return_value = 2
+        self.assertFalse(interface_has_own_mac("eth0"))
+
+
 class TestGetInterfacesByMac(CiTestCase):
     _data = {'bonds': ['bond1'],
              'bridges': ['bridge1'],