Ignore IPv6 link local addresses

Prevent IPA from picking up the IPv6 link-local address
as a callback_url in cases where it gets tried before other
addressing methods havn't complete yet. In this scenario IPA
sleeps for 10 seconds and then retries giving the nic a chance to
configure its routable IP address.

Change-Id: Ic53334c630180f0d77bb0231e548d2c44bfe55ca
Closes-Bug: #1732692

ironic_python_agent/agent.py

@@ -21,6 +21,7 @@ import threading
 import time
 from wsgiref import simple_server
 
+import netaddr
 from oslo_concurrency import processutils
 from oslo_config import cfg
 from oslo_log import log
@@ -214,7 +215,12 @@ class IronicPythonAgent(base.ExecuteCommandMixin):
             return
 
         try:
-            return out.strip().split('\n')[0].split('src')[1].split()[0]
+            source = out.strip().split('\n')[0].split('src')[1].split()[0]
+            if netaddr.IPAddress(source).is_link_local():
+                LOG.info('Ignoring link-local source to %(dest)s: %(rec)s',
+                         {'dest': dest, 'rec': out})
+                return
+            return source
         except IndexError:
             LOG.warning('No route to host %(dest)s, route record: %(rec)s',
                         {'dest': dest, 'rec': out})

ironic_python_agent/tests/unit/test_agent.py

@@ -504,6 +504,14 @@ class TestBaseAgent(ironic_agent_base.IronicAgentTest):
         source = self.agent._get_route_source('XXX')
         self.assertEqual('1:2::3:4', source)
 
+    @mock.patch.object(utils, 'execute', autospec=True)
+    def test_get_route_source_ipv6_linklocal(self, mock_execute):
+        mock_execute.return_value = (
+            'XXX src fe80::1234:1234:1234:1234 metric XXX\n    cache', None)
+
+        source = self.agent._get_route_source('XXX')
+        self.assertIsNone(source)
+
     @mock.patch.object(agent, 'LOG', autospec=True)
     @mock.patch.object(utils, 'execute', autospec=True)
     def test_get_route_source_indexerror(self, mock_execute, mock_log):

releasenotes/notes/no-link-local-2e861978c5c7bf30.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - Fixes the issue where link-local IP addresses were sometimes used as part
+    of the callback URL given to ironic. The routable address is used instead.
+    See `bug 1732692 <https://bugs.launchpad.net/ironic-python-agent/+bug/1732692>`_
+    for more details.