Continue bringing up interfaces even if one fails

Currently os-net-config exits immediately if an interface fails to
come up.  This causes problems when we call it with a failsafe
configuration because it can result in working interfaces not
being configured if there are also non-functional interfaces, which
can leave a system unreachable over the network even though it may
have a working connection.

This change stores errors and handles them after all interfaces have
been processed to allow os-net-config to do what it can even with an
invalid configuration.  If any failures are detected it will still
cause os-net-config to report failure at the end.

Change-Id: I3bc75e217d0b7c5ae62900f4253ad57ee3720685
Closes-Bug: 1692725

1 files changed, 31 insertions, 0 deletions

diff --git a/os_net_config/tests/test_impl_ifcfg.py b/os_net_config/tests/test_impl_ifcfg.py
index 9ff2bd6..e400c94 100644
--- a/os_net_config/tests/test_impl_ifcfg.py
+++ b/os_net_config/tests/test_impl_ifcfg.py
@@ -19,6 +19,7 @@ import tempfile
 
 from oslo_concurrency import processutils
 
+import os_net_config
 from os_net_config import impl_ifcfg
 from os_net_config import NetConfig
 from os_net_config import objects
@@ -1231,3 +1232,33 @@ class TestIfcfgNetConfigApply(base.TestCase):
         self.provider.add_interface(interface)
         self.provider.apply()
         self.assertNotIn('Restart openvswitch', execute_strings)
+
+    def _failed_execute(*args, **kwargs):
+        if kwargs.get('check_exit_code', True):
+            raise processutils.ProcessExecutionError('Test stderr',
+                                                     'Test stdout',
+                                                     str(kwargs))
+
+    def test_interface_failure(self):
+        self.stubs.Set(processutils, 'execute', self._failed_execute)
+        v4_addr = objects.Address('192.168.1.2/24')
+        interface = objects.Interface('em1', addresses=[v4_addr])
+        self.provider.add_interface(interface)
+
+        self.assertRaises(os_net_config.ConfigurationError,
+                          self.provider.apply)
+        self.assertEqual(1, len(self.provider.errors))
+
+    def test_interface_failure_multiple(self):
+        self.stubs.Set(processutils, 'execute', self._failed_execute)
+        v4_addr = objects.Address('192.168.1.2/24')
+        interface = objects.Interface('em1', addresses=[v4_addr])
+        v4_addr2 = objects.Address('192.168.2.2/24')
+        interface2 = objects.Interface('em2', addresses=[v4_addr2])
+        self.provider.add_interface(interface)
+        self.provider.add_interface(interface2)
+
+        self.assertRaises(os_net_config.ConfigurationError,
+                          self.provider.apply)
+        # Even though the first one failed, we should have attempted both
+        self.assertEqual(2, len(self.provider.errors))