Merge lp:~blake-rouse/maas/fix-1401983-1.7 into lp:maas/1.7

[Blake Rouse]

Previously every PXE request would update the nodes pxe_mac link even if it was already that value. This make sure that it is only update when the mac address that was PXE booted changes.

Backport: https://code.launchpad.net/~blake-rouse/maas/fix-1401983/+merge/244646

[Blake Rouse (blake-rouse)]

Self-approve for backport.

review: Approve

=== modified file 'src/maasserver/api/pxeconfig.py'
--- src/maasserver/api/pxeconfig.py	2014-12-09 10:10:58 +0000
+++ src/maasserver/api/pxeconfig.py	2014-12-12 22:03:49 +0000
@@ -166,9 +166,12 @@
     node = get_node_from_mac_string(request_mac)
 
     if node is not None:
-        # Update the record of which MAC address this node uses to PXE boot.
-        node.pxe_mac = MACAddress.objects.get(mac_address=request_mac)
-        node.save()
+        # Only update the PXE booting interface for the node if it has
+        # changed.
+        if (node.pxe_mac is None or
+                node.pxe_mac.mac_address != request_mac):
+            node.pxe_mac = MACAddress.objects.get(mac_address=request_mac)
+            node.save()
 
     if node is None or node.get_boot_purpose() == "commissioning":
         osystem = Config.objects.get_config('commissioning_osystem')

=== modified file 'src/maasserver/api/tests/test_pxeconfig.py'
--- src/maasserver/api/tests/test_pxeconfig.py	2014-12-09 10:10:58 +0000
+++ src/maasserver/api/tests/test_pxeconfig.py	2014-12-12 22:03:49 +0000
@@ -40,6 +40,7 @@
     Config,
     Event,
     MACAddress,
+    Node,
     )
 from maasserver.preseed import (
     compose_enlistment_preseed_url,
@@ -503,9 +504,19 @@
                 description,
                 Event.objects.get(node=node).description)
 
-    def test_pxeconfig_updates_pxe_mac_for_existing_node(self):
+    def test_pxeconfig_sets_pxe_mac_when_empty(self):
+        node = factory.make_Node(mac=True)
+        mac = node.macaddress_set.first()
+        params = self.get_default_params()
+        params['mac'] = mac.mac_address
+        self.client.get(reverse('pxeconfig'), params)
+        node = reload_object(node)
+        self.assertEqual(mac, node.pxe_mac)
+
+    def test_pxeconfig_updates_pxe_mac_when_changed(self):
         node = factory.make_Node()
         node.pxe_mac = factory.make_MACAddress(node=node)
+        node.save()
         mac = factory.make_MACAddress(node=node)
         params = self.get_default_params()
         params['mac'] = mac.mac_address
@@ -513,6 +524,16 @@
         node = reload_object(node)
         self.assertEqual(mac, node.pxe_mac)
 
+    def test_pxeconfig_doesnt_update_pxe_mac_when_same(self):
+        node = factory.make_Node()
+        node.pxe_mac = factory.make_MACAddress(node=node)
+        node.save()
+        params = self.get_default_params()
+        params['mac'] = node.pxe_mac.mac_address
+        mock_save = self.patch(Node, 'save')
+        self.client.get(reverse('pxeconfig'), params)
+        self.assertThat(mock_save, MockNotCalled())
+
     def test_pxeconfig_returns_commissioning_os_series_for_other_oses(self):
         osystem = Config.objects.get_config('default_osystem')
         release = Config.objects.get_config('default_distro_series')