Merge ~dojordan/cloud-init:fix_azure_hostname into cloud-init:master

[Douglas Jordan]

This commit fixes get_hostname on the AzureDataSource.

LP: #1754495

This commit fixes get_hostname on the AzureDataSource.

LP #1754495

[Server Team CI bot (server-team-bot)]

PASSED: Continuous integration, rev:a0fffc2fffc8db3fa32a41f0eda7c2f162e3275c
https://jenkins.ubuntu.com/server/job/cloud-init-ci/830/
Executed test runs:
    SUCCESS: Checkout
    SUCCESS: Unit & Style Tests
    SUCCESS: Ubuntu LTS: Build
    SUCCESS: Ubuntu LTS: Integration
    SUCCESS: MAAS Compatability Testing
    IN_PROGRESS: Declarative: Post Actions

Click here to trigger a rebuild:
https://jenkins.ubuntu.com/server/job/cloud-init-ci/830/rebuild

review: Approve (continuous-integration)

[Chad Smith (chad.smith)]

approve with a minor ask for a unit test.

review: Approve

dbf110c... by Douglas Jordan on 2018-03-09

Adding UT coverage and checking if iterable type first

[Server Team CI bot (server-team-bot)]

PASSED: Continuous integration, rev:dbf110cb3a81f815b73536b2ce3da1f29c62c223
https://jenkins.ubuntu.com/server/job/cloud-init-ci/834/
Executed test runs:
    SUCCESS: Checkout
    SUCCESS: Unit & Style Tests
    SUCCESS: Ubuntu LTS: Build
    SUCCESS: Ubuntu LTS: Integration
    SUCCESS: MAAS Compatability Testing
    IN_PROGRESS: Declarative: Post Actions

Click here to trigger a rebuild:
https://jenkins.ubuntu.com/server/job/cloud-init-ci/834/rebuild

review: Approve (continuous-integration)

[Chad Smith (chad.smith)]

An upstream commit landed for this bug.

To view that commit see the following URL:
https://git.launchpad.net/cloud-init/commit/?id=f891df34

[Server Team CI bot (server-team-bot)]

PASSED: Continuous integration, rev:
https://jenkins.ubuntu.com/server/job/cloud-init-ci/836/
Executed test runs:
    SUCCESS: Checkout
    SUCCESS: Unit & Style Tests
    SUCCESS: Ubuntu LTS: Build
    SUCCESS: Ubuntu LTS: Integration
    SUCCESS: MAAS Compatability Testing
    IN_PROGRESS: Declarative: Post Actions

Click here to trigger a rebuild:
https://jenkins.ubuntu.com/server/job/cloud-init-ci/836/rebuild

review: Approve (continuous-integration)

diff --git a/cloudinit/sources/DataSourceAzure.py b/cloudinit/sources/DataSourceAzure.py
index 4bcbf3a..0bb7fad 100644
--- a/cloudinit/sources/DataSourceAzure.py
+++ b/cloudinit/sources/DataSourceAzure.py
@@ -223,6 +223,8 @@ DEF_PASSWD_REDACTION = 'REDACTED'
 
 
 def get_hostname(hostname_command='hostname'):
+    if not isinstance(hostname_command, (list, tuple)):
+        hostname_command = (hostname_command,)
     return util.subp(hostname_command, capture=True)[0].strip()
 
 
diff --git a/tests/unittests/test_datasource/test_azure.py b/tests/unittests/test_datasource/test_azure.py
index 254e987..da7da0c 100644
--- a/tests/unittests/test_datasource/test_azure.py
+++ b/tests/unittests/test_datasource/test_azure.py
@@ -643,6 +643,21 @@ fdescfs            /dev/fd          fdescfs rw              0 0
         expected_config['config'].append(blacklist_config)
         self.assertEqual(netconfig, expected_config)
 
+    @mock.patch("cloudinit.sources.DataSourceAzure.util.subp")
+    def test_get_hostname_with_no_args(self, subp):
+        dsaz.get_hostname()
+        subp.assert_called_once_with(("hostname",), capture=True)
+
+    @mock.patch("cloudinit.sources.DataSourceAzure.util.subp")
+    def test_get_hostname_with_string_arg(self, subp):
+        dsaz.get_hostname(hostname_command="hostname")
+        subp.assert_called_once_with(("hostname",), capture=True)
+
+    @mock.patch("cloudinit.sources.DataSourceAzure.util.subp")
+    def test_get_hostname_with_iterable_arg(self, subp):
+        dsaz.get_hostname(hostname_command=("hostname",))
+        subp.assert_called_once_with(("hostname",), capture=True)
+
 
 class TestAzureBounce(CiTestCase):