Create scope for docker client specific errors

With more granular and specific exceptions user
will be able to handle errors properly.

Also changed raising of Exception to more specific
TypeError which python raises in case of wrong
arguments.

docker/auth/auth.py

@@ -20,6 +20,7 @@ import os
 import six
 
 from ..utils import utils
+from docker import errors
 
 INDEX_URL = 'https://index.docker.io/v1/'
 DOCKER_CONFIG_FILENAME = '.dockercfg'
@@ -45,18 +46,19 @@ def expand_registry_url(hostname):
 
 def resolve_repository_name(repo_name):
     if '://' in repo_name:
-        raise ValueError('Repository name cannot contain a '
-                         'scheme ({0})'.format(repo_name))
+        raise errors.InvalidRepository(
+            'Repository name cannot contain a scheme ({0})'.format(repo_name))
     parts = repo_name.split('/', 1)
     if '.' not in parts[0] and ':' not in parts[0] and parts[0] != 'localhost':
         # This is a docker index repo (ex: foo/bar or ubuntu)
         return INDEX_URL, repo_name
     if len(parts) < 2:
-        raise ValueError('Invalid repository name ({0})'.format(repo_name))
+        raise errors.InvalidRepository(
+            'Invalid repository name ({0})'.format(repo_name))
 
     if 'index.docker.io' in parts[0]:
-        raise ValueError('Invalid repository name,'
-                         'try "{0}" instead'.format(parts[1]))
+        raise errors.InvalidRepository(
+            'Invalid repository name, try "{0}" instead'.format(parts[1]))
 
     return expand_registry_url(parts[0]), parts[1]
 
@@ -147,7 +149,8 @@ def load_config(root=None):
             data.append(line.strip().split(' = ')[1])
         if len(data) < 2:
             # Not enough data
-            raise Exception('Invalid or empty configuration file!')
+            raise errors.InvalidConfigFile(
+                'Invalid or empty configuration file!')
 
         username, password = decode_auth(data[0])
         conf[INDEX_URL] = {

docker/client.py

@@ -341,7 +341,7 @@ class Client(requests.Session):
               nocache=False, rm=False, stream=False, timeout=None):
         remote = context = headers = None
         if path is None and fileobj is None:
-            raise Exception("Either path or fileobj needs to be provided.")
+            raise TypeError("Either path or fileobj needs to be provided.")
 
         if fileobj is not None:
             context = utils.mkbuildcontext(fileobj)

docker/errors.py

@@ -0,0 +1,24 @@
+#    Copyright 2014 dotCloud 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.
+
+
+class DockerException(Exception):
+    pass
+
+
+class InvalidRepository(DockerException):
+    pass
+
+
+class InvalidConfigFile(DockerException):
+    pass