Move custom exceptions in errors.py (#22)

docker_explorer/de.py

@@ -24,6 +24,7 @@
 import os
 import sys
 
+from docker_explorer import errors
 from docker_explorer.lib import aufs
 from docker_explorer.lib import overlay
 
@@ -33,19 +34,6 @@
 sys.stdout = codecs.getwriter('utf8')(sys.stdout)
 
 
-class BadStorageException(Exception):
-  """Raised when the Storage method detection failed."""
-
-  def __init__(self, message):
-    """Constructor for a BadStorageException.
-
-    Args:
-      message (str): the error message.
-    """
-    super(BadStorageException, self).__init__(message)
-    self.message = message
-
-
 class DockerExplorer(object):
   """Main class for the DockerExplorer tool.
 
@@ -70,14 +58,14 @@ def DetectStorage(self):
     http://jpetazzo.github.io/assets/2015-06-04-deep-dive-into-docker-storage-drivers.html#60
 
     Raises:
-      BadStorageException: If the storage backend couldn't be detected.
+      errors.BadStorageException: If the storage backend couldn't be detected.
     """
     if not os.path.isdir(self.docker_directory):
-      error_msg = (
+      err_message = (
           '{0:s} is not a Docker directory\n'
           'Please specify the Docker\'s directory path.\n'
           'hint: de.py -r /var/lib/docker').format(self.docker_directory)
-      raise BadStorageException(error_msg)
+      raise errors.BadStorageException(err_message)
 
     if os.path.isfile(
         os.path.join(self.docker_directory, 'repositories-aufs')):
@@ -99,7 +87,7 @@ def DetectStorage(self):
           'Make sure the docker directory ({0:s}) is correct. '
           'If it is correct, you might want to run this script'
           ' with higher privileges.'.format(self.docker_directory))
-      raise BadStorageException(err_message)
+      raise errors.BadStorageException(err_message)
 
   def AddBasicOptions(self, argument_parser):
     """Adds the global options to the argument_parser.

docker_explorer/errors.py

@@ -0,0 +1,38 @@
+# -*- coding: utf-8 -*-
+# Copyright 2016 Google 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.
+"""Custom exceptions."""
+
+from __future__ import print_function, unicode_literals
+
+
+class DockerExplorerError(Exception):
+  """Base class for DockerExplorer custom errors."""
+
+  def __init__(self, message):
+    """Constructor for a DockerExplorerError.
+
+    Args:
+      message (str): the error message.
+    """
+    super(DockerExplorerError, self).__init__(message)
+    self.message = message
+
+
+class BadContainerException(DockerExplorerError):
+  """Raised when there was an issue parsing a Container configuration file."""
+
+
+class BadStorageException(DockerExplorerError):
+  """Raised when the Storage method detection failed."""

tests.py

@@ -24,6 +24,7 @@
 import unittest
 
 from docker_explorer import de
+from docker_explorer import errors
 
 from docker_explorer.lib import aufs
 from docker_explorer.lib import overlay
@@ -110,7 +111,7 @@ def testDetectStorage(self):
         'Please specify the Docker\'s directory path.\n'
         'hint: de.py -r /var/lib/docker')
 
-    with self.assertRaises(de.BadStorageException) as err:
+    with self.assertRaises(errors.BadStorageException) as err:
       de_test_object.DetectStorage()
     self.assertEqual(expected_error_message, err.exception.message)
 
@@ -266,7 +267,7 @@ def testDetectStorage(self):
         'Please specify the Docker\'s directory path.\n'
         'hint: de.py -r /var/lib/docker')
 
-    with self.assertRaises(de.BadStorageException) as err:
+    with self.assertRaises(errors.BadStorageException) as err:
       de_test_object.DetectStorage()
     self.assertEqual(expected_error_message, err.exception.message)
 
@@ -421,7 +422,7 @@ def testDetectStorage(self):
         'Please specify the Docker\'s directory path.\n'
         'hint: de.py -r /var/lib/docker')
 
-    with self.assertRaises(de.BadStorageException) as err:
+    with self.assertRaises(errors.BadStorageException) as err:
       de_test_object.DetectStorage()
     self.assertEqual(expected_error_message, err.exception.message)