Email Working Directory Utility Method

A utility method that ensures that a typo inside of the email plugin
won't ruin our day. By using this method instead we can change the
location of our working directories in one place, rather than several.

Change-Id: I3a562d839544c55deee22a85c435df629c67edc0

storyboard/plugin/email/__init__.py

@@ -15,6 +15,9 @@
 from oslo.config import cfg
 from oslo_log import log
 
+from storyboard.common.working_dir import get_plugin_directory
+
+
 CONF = cfg.CONF
 LOG = log.getLogger(__name__)
 
@@ -62,3 +65,11 @@ PLUGIN_OPTS = [
 ]
 
 CONF.register_opts(PLUGIN_OPTS, "plugin_email")
+
+
+def get_email_directory():
+    """A shared utility method that always provides the same working
+    directory. Error handling is explicitly not provided, as the methods used
+    'should' be consistent about the errors they themselves raise.
+    """
+    return get_plugin_directory("email")

storyboard/tests/plugin/email/test_init.py

@@ -12,15 +12,19 @@
 # implied. See the License for the specific language governing permissions and
 # limitations under the License.
 
+import os
+import stat
+
 from oslo.config import cfg
 
+from storyboard.plugin.email import get_email_directory
 from storyboard.tests import base
 
 
 CONF = cfg.CONF
 
 
-class TestConfiguration(base.TestCase):
+class TestEmailConfiguration(base.TestCase):
     def test_configuration_defaults(self):
         self.assertIsNotNone(CONF.plugin_email)
 
@@ -34,3 +38,35 @@ class TestConfiguration(base.TestCase):
         self.assertEqual(None, conf.smtp_ssl_certfile)
         self.assertEqual(None, conf.smtp_user)
         self.assertEqual(None, conf.smtp_password)
+
+
+class TestGetEmailDirectory(base.WorkingDirTestCase):
+    def test_get_email_directory(self):
+        """Can we resolve the email directory? Most of this testing also
+        exists in test_working_dir, however it behooves us to test it here as
+        well.
+        """
+        expected_path = os.path.realpath(os.path.join(CONF.working_directory,
+                                                      'plugin', 'email'))
+        self.assertFalse(os.path.exists(expected_path))
+
+        resolved_path = get_email_directory()
+
+        self.assertEqual(expected_path, resolved_path)
+        self.assertTrue(os.path.exists(CONF.working_directory))
+        self.assertTrue(os.path.exists(expected_path))
+
+        self.assertTrue(os.access(CONF.working_directory, os.W_OK))
+        self.assertTrue(os.access(expected_path, os.W_OK))
+
+    def test_get_email_directory_not_creatable(self):
+        """Assert that the get_email_directory() method raises an error if
+        it cannot be created.
+        """
+
+        # Set the permissions
+        os.chmod(CONF.working_directory,
+                 stat.S_IRUSR + stat.S_IRGRP + stat.S_IROTH)
+
+        # Make sure it raises an exception.
+        self.assertRaises(IOError, get_email_directory)