Use FHS-compliant default base directory

/opt/stack as the default base directory is not very friendly to
non-OpenStack users, so this changes the default base directory
to reside in /usr/libexec.  The /opt/stack path will continue to
work for now so any existing users will not be broken by the change.

Also changes the directory name from os-config-refresh to
os-refresh-config to better align with the os-apply-config naming.

Change-Id: I98e93d91685ae25ae74a5470483a1cc8b97da4e5

os_refresh_config/os_refresh_config.py

@@ -22,8 +22,33 @@ import subprocess
 import sys
 import time
 
-BASE_DIR = os.environ.get('OS_REFRESH_CONFIG_BASE_DIR',
-                          '/opt/stack/os-config-refresh')
+OLD_BASE_DIR = '/opt/stack/os-config-refresh'
+DEFAULT_BASE_DIR = '/usr/libexec/os-refresh-config'
+
+
+def default_base_dir():
+    """Determine the default base directory path
+
+    If the OS_REFRESH_CONFIG_BASE_DIR environment variable is set,
+    use its value.
+    Otherwise, prefer the new default path, but still allow the old one for
+    backwards compatibility.
+    """
+    base_dir = os.environ.get('OS_REFRESH_CONFIG_BASE_DIR')
+    if base_dir is None:
+        # NOTE(bnemec): Prefer the new location, but still allow the old one.
+        if os.path.isdir(OLD_BASE_DIR) and not os.path.isdir(DEFAULT_BASE_DIR):
+            logging.warning('Base directory %s is deprecated. The recommended '
+                            'base directory is %s',
+                            OLD_BASE_DIR, DEFAULT_BASE_DIR)
+            base_dir = OLD_BASE_DIR
+        else:
+            base_dir = DEFAULT_BASE_DIR
+    return base_dir
+
+
+BASE_DIR = default_base_dir()
+
 PHASES = ['pre-configure',
           'configure',
           'post-configure',

os_refresh_config/tests/test_os_refresh_config.py

@@ -0,0 +1,37 @@
+# Copyright 2014 Red Hat, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import mock
+import testtools
+
+from os_refresh_config import os_refresh_config
+
+
+class TestRefreshConfig(testtools.TestCase):
+    def test_default_base_dir(self):
+        default = '/usr/libexec/os-refresh-config'
+        with mock.patch('os.path.isdir', lambda x: x == default):
+            self.assertEqual(default, os_refresh_config.default_base_dir())
+
+    def test_default_base_dir_deprecated(self):
+        default = '/opt/stack/os-config-refresh'
+        with mock.patch('os.path.isdir', lambda x: x == default):
+            self.assertEqual(default, os_refresh_config.default_base_dir())
+
+    def test_default_base_dir_both(self):
+        default = '/usr/libexec/os-refresh-config'
+        deprecated = '/opt/stack/os-config-refresh'
+        with mock.patch('os.path.isdir', lambda x: (x == default or
+                                                    x == deprecated)):
+            self.assertEqual(default, os_refresh_config.default_base_dir())

test-requirements.txt

@@ -4,6 +4,7 @@ Babel>=1.3
 coverage>=3.6
 discover
 fixtures>=0.3.14
+mock>=1.0
 python-subunit>=0.0.18
 sphinx>=1.1.2,<1.2
 testrepository>=0.0.18