Fix export_info NIC IP address update

This patch makes sure that exported instances never lose IP addressing
information, even after replicating with instance off.

coriolis/tasks/replica_tasks.py

@@ -74,6 +74,28 @@ def _check_ensure_volumes_info_ordering(export_info, volumes_info):
     return ordered_volumes_info
 
 
+def _preserve_old_export_info_nic_ips(old_export_info, new_export_info):
+    def _get_nic(nics_info, nic_id):
+        for nic_info in nics_info:
+            if nic_info['id'] == nic_id:
+                return nic_info
+
+    old_nics_info = old_export_info.get('devices', {}).get('nics', [])
+    new_nics_info = new_export_info.get('devices', {}).get('nics', [])
+
+    for new_info in new_nics_info:
+        old_info = _get_nic(old_nics_info, new_info['id'])
+        if old_info:
+            old_ips = old_info.get('ip_addresses', [])
+            new_ips = new_info.get('ip_addresses', [])
+            if not new_ips:
+                new_info['ip_addresses'] = old_ips
+
+
+def _update_export_info(old_export_info, result_export_info):
+    _preserve_old_export_info_nic_ips(old_export_info, result_export_info)
+
+
 class GetInstanceInfoTask(base.TaskRunner):
     """ Task which gathers the export info for a VM.  """
 
@@ -104,12 +126,14 @@ def _run(self, ctxt, instance, origin, destination, task_info,
         connection_info = base.get_connection_info(ctxt, origin)
 
         source_environment = task_info['source_environment']
+        old_export_info = task_info.get('export_info', {})
         export_info = provider.get_replica_instance_info(
             ctxt, connection_info, source_environment, instance)
 
         # Validate the output
         schemas.validate_value(
             export_info, schemas.CORIOLIS_VM_EXPORT_INFO_SCHEMA)
+        _update_export_info(old_export_info, export_info)
 
         return {
             'export_info': export_info}

coriolis/tests/tasks/data/test_nic_ips_update.yml

@@ -0,0 +1,61 @@
+# Provider receives first IP address
+- old_export_info:
+    devices:
+      nics: []
+  new_export_info:
+    devices:
+      nics:
+        - id: 1
+          ip_addresses: ['10.0.0.1']
+  expected_export_info:
+    devices:
+      nics:
+        - id: 1
+          ip_addresses: ['10.0.0.1']
+
+# Export NIC changes
+- old_export_info:
+    devices:
+      nics:
+        - id: 1
+          ip_addresses: ['10.0.0.1']
+  new_export_info:
+    devices:
+      nics:
+        - id: 2
+          ip_addresses: []
+  expected_export_info:
+    devices:
+      nics:
+        - id: 2
+          ip_addresses: []
+
+# Export NIC doesn't report IP address (result keeps old one)
+- old_export_info:
+    devices:
+      nics:
+        - id: 1
+          ip_addresses: ['10.0.0.1']
+  new_export_info:
+    devices:
+      nics:
+        - id: 1
+          ip_addresses: []
+  expected_export_info:
+    devices:
+      nics:
+        - id: 1
+          ip_addresses: ['10.0.0.1']
+
+# No NICs get reported
+- old_export_info:
+    devices:
+      nics:
+        - id: 1
+          ip_addresses: ['10.0.0.1']
+  new_export_info:
+    devices:
+      nics: []
+  expected_export_info:
+    devices:
+      nics: []

coriolis/tests/tasks/test_replica_tasks.py

@@ -53,6 +53,14 @@ def test__check_ensure_volumes_info_ordering(
             mock_sanitize.has_calls(expected_calls)
             self.assertEqual(result, expected_result)
 
+    @ddt.file_data("data/test_nic_ips_update.yml")
+    @ddt.unpack
+    def test__preserve_old_export_info_nic_ips(
+            self, old_export_info, new_export_info, expected_export_info):
+        replica_tasks._preserve_old_export_info_nic_ips(
+            old_export_info, new_export_info)
+        self.assertEqual(new_export_info, expected_export_info)
+
 
 class GetInstanceInfoTaskTestCase(test_base.CoriolisBaseTestCase):