Make tests work with Python 3.8 (#139)

* Make DistroChecker test work with Python 3.8

In Python 3.8, `platform.linux_distribution` has been removed. This was
anticipated, and the cloud-init code uses its own
`util.get_linux_distro` instead, which works fine w/o
`platform.linux_distribution`. However, these tests still try to mock
the platform function, which fails if it doesn't exist (Python 3.8).
Instead, mock the new function here, as this is a test for code that
depends on it rather than the function itself.

* Make GetLinuxDistro tests work with Python 3.8

In Python 3.8, `platform.dist` was removed, so allow mock to create the
function by setting `create=True`.

* Make linter happy in Python 3.8

Suppress E1101(no-member) as this function was removed.

3 files changed, 9 insertions, 9 deletions

diff --git a/cloudinit/analyze/tests/test_boot.py b/cloudinit/analyze/tests/test_boot.py
index 706e2cc0..f4001c14 100644
--- a/cloudinit/analyze/tests/test_boot.py
+++ b/cloudinit/analyze/tests/test_boot.py
@@ -12,17 +12,17 @@ class TestDistroChecker(CiTestCase):
     @mock.patch('cloudinit.util.system_info', return_value={'dist': ('', '',
                                                                      ''),
                                                             'system': ''})
-    @mock.patch('platform.linux_distribution', return_value=('', '', ''))
+    @mock.patch('cloudinit.util.get_linux_distro', return_value=('', '', ''))
     @mock.patch('cloudinit.util.is_FreeBSD', return_value=False)
-    def test_blank_distro(self, m_sys_info, m_linux_distribution, m_free_bsd):
+    def test_blank_distro(self, m_sys_info, m_get_linux_distro, m_free_bsd):
         self.assertEqual(err_code, dist_check_timestamp())
 
     @mock.patch('cloudinit.util.system_info', return_value={'dist': ('', '',
                                                                      '')})
-    @mock.patch('platform.linux_distribution', return_value=('', '', ''))
+    @mock.patch('cloudinit.util.get_linux_distro', return_value=('', '', ''))
     @mock.patch('cloudinit.util.is_FreeBSD', return_value=True)
     def test_freebsd_gentoo_cant_find(self, m_sys_info,
-                                      m_linux_distribution, m_is_FreeBSD):
+                                      m_get_linux_distro, m_is_FreeBSD):
         self.assertEqual(err_code, dist_check_timestamp())
 
     @mock.patch('cloudinit.util.subp', return_value=(0, 1))
diff --git a/cloudinit/tests/test_util.py b/cloudinit/tests/test_util.py
index 64ed82ea..be100646 100644
--- a/cloudinit/tests/test_util.py
+++ b/cloudinit/tests/test_util.py
@@ -523,7 +523,7 @@ class TestGetLinuxDistro(CiTestCase):
         self.assertEqual(
             ('opensuse-tumbleweed', '20180920', platform.machine()), dist)
 
-    @mock.patch('platform.dist')
+    @mock.patch('platform.dist', create=True)
     def test_get_linux_distro_no_data(self, m_platform_dist, m_path_exists):
         """Verify we get no information if os-release does not exist"""
         m_platform_dist.return_value = ('', '', '')
@@ -531,7 +531,7 @@ class TestGetLinuxDistro(CiTestCase):
         dist = util.get_linux_distro()
         self.assertEqual(('', '', ''), dist)
 
-    @mock.patch('platform.dist')
+    @mock.patch('platform.dist', create=True)
     def test_get_linux_distro_no_impl(self, m_platform_dist, m_path_exists):
         """Verify we get an empty tuple when no information exists and
         Exceptions are not propagated"""
@@ -540,7 +540,7 @@ class TestGetLinuxDistro(CiTestCase):
         dist = util.get_linux_distro()
         self.assertEqual(('', '', ''), dist)
 
-    @mock.patch('platform.dist')
+    @mock.patch('platform.dist', create=True)
     def test_get_linux_distro_plat_data(self, m_platform_dist, m_path_exists):
         """Verify we get the correct platform information"""
         m_platform_dist.return_value = ('foo', '1.1', 'aarch64')
diff --git a/cloudinit/util.py b/cloudinit/util.py
index 9d9d5c72..830c8e54 100644
--- a/cloudinit/util.py
+++ b/cloudinit/util.py
@@ -635,8 +635,8 @@ def get_linux_distro():
     else:
         dist = ('', '', '')
         try:
-            # Will be removed in 3.7
-            dist = platform.dist()  # pylint: disable=W1505
+            # Was removed in 3.8
+            dist = platform.dist()  # pylint: disable=W1505,E1101
         except Exception:
             pass
         finally: