DataSourceSmartOS: sdc:hostname is ignored

There are three potential sources of the hostname, one of which is
documented SmartOS's vmadm(1M) via the hostname property.  That
property's value is retrieved via the sdc:hostname key.  The other
two sources for the hostname are a hostname key in customer_metadata
and the VM's uuid (sdc:uuid).  Of these three, the sdc:hostname value
is not used in a meaningful way by DataSourceSmartOS.

This fix changes the fallback mechanism when hostname is not
specified in customer_metadata.  The order of precedence for setting
the hostname is now 1) hostname in customer_metadata,
2) sdc:hostname, then 3) sdc:uuid.

LP: #1765085

2 files changed, 36 insertions, 2 deletions

diff --git a/cloudinit/sources/DataSourceSmartOS.py b/cloudinit/sources/DataSourceSmartOS.py
index d4386fec..0ef10035 100644
--- a/cloudinit/sources/DataSourceSmartOS.py
+++ b/cloudinit/sources/DataSourceSmartOS.py
@@ -11,7 +11,7 @@
 #    SmartOS hosts use a serial console (/dev/ttyS1) on KVM Linux Guests
 #        The meta-data is transmitted via key/value pairs made by
 #        requests on the console. For example, to get the hostname, you
-#        would send "GET hostname" on /dev/ttyS1.
+#        would send "GET sdc:hostname" on /dev/ttyS1.
 #        For Linux Guests running in LX-Brand Zones on SmartOS hosts
 #        a socket (/native/.zonecontrol/metadata.sock) is used instead
 #        of a serial console.
@@ -273,8 +273,14 @@ class DataSourceSmartOS(sources.DataSource):
         write_boot_content(u_data, u_data_f)
 
         # Handle the cloud-init regular meta
+
+        # The hostname may or may not be qualified with the local domain name.
+        # This follows section 3.14 of RFC 2132.
         if not md['local-hostname']:
-            md['local-hostname'] = md['instance-id']
+            if md['hostname']:
+                md['local-hostname'] = md['hostname']
+            else:
+                md['local-hostname'] = md['instance-id']
 
         ud = None
         if md['user-data']:
diff --git a/tests/unittests/test_datasource/test_smartos.py b/tests/unittests/test_datasource/test_smartos.py
index 6fd431f9..b926263f 100644
--- a/tests/unittests/test_datasource/test_smartos.py
+++ b/tests/unittests/test_datasource/test_smartos.py
@@ -437,6 +437,34 @@ class TestSmartOSDataSource(FilesystemMockingTestCase):
         self.assertEqual(MOCK_RETURNS['hostname'],
                          dsrc.metadata['local-hostname'])
 
+    def test_hostname_if_no_sdc_hostname(self):
+        my_returns = MOCK_RETURNS.copy()
+        my_returns['sdc:hostname'] = 'sdc-' + my_returns['hostname']
+        dsrc = self._get_ds(mockdata=my_returns)
+        ret = dsrc.get_data()
+        self.assertTrue(ret)
+        self.assertEqual(my_returns['hostname'],
+                         dsrc.metadata['local-hostname'])
+
+    def test_sdc_hostname_if_no_hostname(self):
+        my_returns = MOCK_RETURNS.copy()
+        my_returns['sdc:hostname'] = 'sdc-' + my_returns['hostname']
+        del my_returns['hostname']
+        dsrc = self._get_ds(mockdata=my_returns)
+        ret = dsrc.get_data()
+        self.assertTrue(ret)
+        self.assertEqual(my_returns['sdc:hostname'],
+                         dsrc.metadata['local-hostname'])
+
+    def test_sdc_uuid_if_no_hostname_or_sdc_hostname(self):
+        my_returns = MOCK_RETURNS.copy()
+        del my_returns['hostname']
+        dsrc = self._get_ds(mockdata=my_returns)
+        ret = dsrc.get_data()
+        self.assertTrue(ret)
+        self.assertEqual(my_returns['sdc:uuid'],
+                         dsrc.metadata['local-hostname'])
+
     def test_userdata(self):
         dsrc = self._get_ds(mockdata=MOCK_RETURNS)
         ret = dsrc.get_data()