Fix SUSE detection on Tumbleweed and SLE15

It seems platform.dist and platform.linux_distribution are broken with
newer operating systems. Specifically /etc/os-release seems to be the
new hotness. EG: opensuse-tumbleweed and fedora-27.

Vendor the distro (1.2.0) package, as not to have external
dependencies installed.

Change-Id: Ib9580aa7fe84a20e44d32248d7b4716456684dbc
Depends-On: https://review.openstack.org/545183/
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

glean/cmd.py

@@ -22,7 +22,6 @@ import errno
 import json
 import logging
 import os
-import platform
 import re
 import subprocess
 import sys
@@ -30,6 +29,7 @@ import time
 
 from glean import systemlock
 from glean import utils
+from glean._vendor import distro
 
 log = logging.getLogger("glean")
 
@@ -1123,10 +1123,11 @@ def main():
     parser = argparse.ArgumentParser(description="Static network config")
     parser.add_argument(
         '-n', '--noop', action='store_true', help='Do not write files')
+    _distro = distro.linux_distribution(
+        full_distribution_name=False)[0].lower()
     parser.add_argument(
-        '--distro', dest='distro',
-        default=platform.dist()[0].lower(),
-        help='Override distro (detected "%s")' % platform.dist()[0].lower())
+        '--distro', dest='distro', default=_distro,
+        help='Override distro (detected "%s")' % _distro)
     parser.add_argument(
         '--root', dest='root', default='/',
         help='Mounted root for config drive info, defaults to /')

glean/tests/test_glean.py

@@ -138,10 +138,7 @@ class TestGlean(base.BaseTestCase):
             return False
         return real_path_exists(path)
 
-    @mock.patch('platform.dist', new_callable=mock.Mock)
     @mock.patch('subprocess.call', return_value=0, new_callable=mock.Mock)
-    @mock.patch('subprocess.check_output', return_value=0,
-                new_callable=mock.Mock)
     @mock.patch('os.unlink', return_value=0, new_callable=mock.Mock)
     @mock.patch('os.symlink', return_value=0, new_callable=mock.Mock)
     @mock.patch('os.path.exists', new_callable=mock.Mock)
@@ -156,21 +153,17 @@ class TestGlean(base.BaseTestCase):
                                 mock_os_path_exists,
                                 mock_os_symlink,
                                 mock_os_unlink,
-                                mock_check_output,
                                 mock_call,
-                                mock_platform_dist,
                                 skip_dns=False):
         """Main test function
 
-        :param distro: distro to return from "platform.dist"
+        :param distro: distro to return from "distro.linux_distribution()"
         :param provider: we will look in fixtures/provider for mocked
                          out files
         :param interface: --interface argument; None for no argument
         :param skip_dns: --skip-dns argument; False for no argument
         """
 
-        mock_platform_dist.return_value = (distro, '', '')
-
         # These functions are watching the path and faking results
         # based on various things
         # XXX : There are several virtual file-systems available, we
@@ -184,6 +177,8 @@ class TestGlean(base.BaseTestCase):
         mock_open.side_effect = functools.partial(
             self.open_side_effect, provider)
 
+        sys.argv.append('--distro=%s' % distro.lower())
+
         if interface:
             sys.argv.append('--interface=%s' % interface)
         if skip_dns: