Ensure that the serial console is always closed.

cloudinit/sources/DataSourceSmartOS.py

@@ -30,9 +30,11 @@
 #       Comments with "@datadictionary" are snippets of the definition
 
 import binascii
+import contextlib
 import os
 import random
 import re
+
 import serial
 
 from cloudinit import log as logging
@@ -371,11 +373,10 @@ def query_data(noun, seed_device, seed_timeout, strip=False, default=None,
     if not noun:
         return False
 
-    ser = get_serial(seed_device, seed_timeout)
+    with contextlib.closing(get_serial(seed_device, seed_timeout)) as ser:
+        client = JoyentMetadataClient(ser)
+        response = client.get_metadata(noun)
 
-    client = JoyentMetadataClient(ser)
-    response = client.get_metadata(noun)
-    ser.close()
     if response is None:
         return default
 

tests/unittests/test_datasource/test_smartos.py

@@ -409,6 +409,18 @@ class TestSmartOSDataSource(helpers.FilesystemMockingTestCase):
         self.assertEqual(dsrc.device_name_to_device('FOO'),
                          mydscfg['disk_aliases']['FOO'])
 
+    @mock.patch('cloudinit.sources.DataSourceSmartOS.JoyentMetadataClient')
+    @mock.patch('cloudinit.sources.DataSourceSmartOS.get_serial')
+    def test_serial_console_closed_on_error(self, get_serial, metadata_client):
+        class OurException(Exception):
+            pass
+        metadata_client.side_effect = OurException
+        try:
+            DataSourceSmartOS.query_data('noun', 'device', 0)
+        except OurException:
+            pass
+        self.assertEqual(1, get_serial.return_value.close.call_count)
+
 
 def apply_patches(patches):
     ret = []