Merge ~bjornt/maas:bug-1884720-2.8 into maas:2.8

[Björn Tillenius]

LP #1884720: Commissioning fails on ppc64 node

Store hardware UUID as None if there is no UUID for the machine.

(cherry picked from commit 94d87f8873e1331253d18b13145c1b015f765b1d)

[Björn Tillenius (bjornt)]

Self-approve backport

review: Approve

[MAAS Lander (maas-lander)]

LANDING
-b bug-1884720-2.8 lp:~bjornt/maas/+git/maas into -b 2.8 lp:~maas-committers/maas

STATUS: FAILED BUILD
LOG: http://maas-ci.internal:8080/job/maas/job/branch-tester/7778/consoleText

[MAAS Lander (maas-lander)]

UNIT TESTS
-b bug-1884720-2.8 lp:~bjornt/maas/+git/maas into -b 2.8 lp:~maas-committers/maas

STATUS: SUCCESS
COMMIT: f0dfb8458632251a4a43b98ce27f462fcf940096

review: Approve

diff --git a/src/metadataserver/builtin_scripts/hooks.py b/src/metadataserver/builtin_scripts/hooks.py
index 96962b5..e07e6a0 100644
--- a/src/metadataserver/builtin_scripts/hooks.py
+++ b/src/metadataserver/builtin_scripts/hooks.py
@@ -405,7 +405,9 @@ def _process_system_information(node, system_data):
         else:
             NodeMetadata.objects.filter(node=node, key=key).delete()
 
-    node.hardware_uuid = system_data.get("uuid")
+    uuid = system_data.get("uuid")
+    # Convert "" to None, so that the unique check isn't triggered.
+    node.hardware_uuid = None if uuid == "" else uuid
 
     # Gather system information. Custom built machines and some Supermicro
     # servers do not provide this information.
diff --git a/src/metadataserver/builtin_scripts/tests/test_hooks.py b/src/metadataserver/builtin_scripts/tests/test_hooks.py
index 3805712..7da60fd 100644
--- a/src/metadataserver/builtin_scripts/tests/test_hooks.py
+++ b/src/metadataserver/builtin_scripts/tests/test_hooks.py
@@ -95,11 +95,13 @@ lldp_output_interface_template = """
 """
 
 
-def make_lxd_system_info(virt_type=None):
+def make_lxd_system_info(virt_type=None, uuid=None):
     if not virt_type:
         virt_type = random.choice(["physical", "container", "virtual-machine"])
+    if uuid is None:
+        uuid = factory.make_UUID()
     return {
-        "uuid": factory.make_UUID(),
+        "uuid": uuid,
         "vendor": factory.make_name("system_vendor"),
         "product": factory.make_name("system_product"),
         "family": factory.make_name("system_family"),
@@ -532,6 +534,7 @@ def make_lxd_output(
     server_name=None,
     virt_type=None,
     with_xenial_network=False,
+    uuid=None,
 ):
     if not resources:
         resources = deepcopy(SAMPLE_LXD_RESOURCES)
@@ -547,7 +550,7 @@ def make_lxd_output(
         ),
         "resources": resources,
     }
-    ret["resources"]["system"] = make_lxd_system_info(virt_type)
+    ret["resources"]["system"] = make_lxd_system_info(virt_type, uuid)
     if with_xenial_network:
         ret["resources"]["network"] = deepcopy(SAMPLE_LXD_XENIAL_NETWORK)
     return ret
@@ -1250,6 +1253,26 @@ class TestProcessLXDResults(MAASServerTestCase):
         node = reload_object(node)
         self.assertEquals(deb_arch, node.architecture)
 
+    def test_sets_uuid(self):
+        node = factory.make_Node()
+        create_IPADDR_OUTPUT_NAME_script(node, IP_ADDR_OUTPUT)
+        uuid = factory.make_UUID()
+        process_lxd_results(node, make_lxd_output_json(uuid=uuid), 0)
+        node = reload_object(node)
+        self.assertEquals(uuid, node.hardware_uuid)
+
+    def test_sets_empty_uuid(self):
+        node = factory.make_Node()
+        create_IPADDR_OUTPUT_NAME_script(node, IP_ADDR_OUTPUT)
+        # LXD reports the uuid as "" if the machine doesn't have one
+        # set.
+        uuid = ""
+        process_lxd_results(node, make_lxd_output_json(uuid=uuid), 0)
+        node = reload_object(node)
+        # In the DB, we store the missing UUID as None, so that the
+        # check for unique UUIDs isn't triggered.
+        self.assertIsNone(node.hardware_uuid)
+
     def test_sets_os_hostname_for_controller(self):
         rack = factory.make_RackController()
         create_IPADDR_OUTPUT_NAME_script(rack, IP_ADDR_OUTPUT)