Implement HTTP Transport

This patch implements the HTTP transport.

Some notes:
    - Consider not having a version for the transport implementation
      since we already have one for the API definition.
    - Consider moving transport implementations under a private package
      since they're not suppose to be inherited nor imported. To load a
      transport users have to use `transport.get_transport(_for)`

Partially-Implements blueprint python-marconiclient-v1

Change-Id: Ie2c70b3c160c5a331bd79765b2f4d69433e5bd73

marconiclient/common/http.py

@@ -23,6 +23,10 @@ class Client(object):
     def __init__(self, *args, **kwargs):
         self.session = requests.session(*args, **kwargs)
 
+    def request(self, *args, **kwargs):
+        """Raw request."""
+        return self.session.request(*args, **kwargs)
+
     def get(self, *args, **kwargs):
         """Does  http GET."""
         return self.session.get(*args, **kwargs)

marconiclient/tests/transport/api.py

@@ -0,0 +1,32 @@
+# Copyright (c) 2013 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.
+
+from marconiclient.transport import api
+
+
+class FakeApi(api.Api):
+    schema = {
+        'test_operation': {
+            'ref': 'test/{name}',
+            'method': 'GET',
+            'properties': {
+                'name': {'type': 'string'},
+                'address': {'type': 'string'}
+            },
+
+            'additionalProperties': False,
+            'required': ['name']
+        }
+    }

marconiclient/transport/api.py

@@ -24,6 +24,26 @@ class Api(object):
     schema = {}
     validators = {}
 
+    def get_schema(self, operation):
+        """Returns the schema for an operation
+
+        :param operation: Operation for which params need
+            to be validated.
+        :type operation: `six.text_type`
+
+        :returns: Operation's schema
+        :rtype: dict
+
+        :raises: `errors.InvalidOperation` if the operation
+            does not exist
+        """
+        try:
+            return self.schema[operation]
+        except KeyError:
+            # TODO(flaper87): gettext support
+            msg = '{0} is not a valid operation'.format(operation)
+            raise errors.InvalidOperation(msg)
+
     def validate(self, operation, params):
         """Validates the request data
 
@@ -44,13 +64,8 @@ class Api(object):
         """
 
         if operation not in self.validators:
-            try:
+            schema = self.get_schema(operation)
-                schema = self.schema[operation]
+            self.validators[operation] = validators.Draft4Validator(schema)
-                self.validators[operation] = validators.Draft4Validator(schema)
-            except KeyError:
-                # TODO(flaper87): gettext support
-                msg = '{0} is not a valid operation'.format(operation)
-                raise errors.InvalidOperation(msg)
 
         try:
             self.validators[operation].validate(params)

marconiclient/transport/http.py

@@ -0,0 +1,59 @@
+# Copyright (c) 2013 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.
+
+from marconiclient.common import http
+from marconiclient.transport import base
+
+
+class HttpTransport(base.Transport):
+
+    def __init__(self, conf):
+        super(HttpTransport, self).__init__(conf)
+        self.client = http.Client()
+
+    def _prepare(self, request):
+        if not request.api:
+            return request.endpoint, 'GET', request
+
+        # TODO(flaper87): Validate if the user
+        # explicitly wants so. Validation must
+        # happen before any other operation here.
+        # request.validate()
+
+        schema = request.api.get_schema(request.operation)
+        ref = schema.get('ref', '')
+        ref_params = {}
+
+        for param in list(request.params.keys()):
+            if '{{{0}}}'.format(param) in ref:
+                ref_params[param] = request.params.pop(param)
+
+        url = '{0}/{1}'.format(request.endpoint.rstrip('/'),
+                               ref.format(**ref_params))
+        return url, schema.get('method', 'GET'), request
+
+    def send(self, request):
+        url, method, request = self._prepare(request)
+
+        # NOTE(flape87): Do not modify
+        # request's headers directly.
+        headers = request.headers.copy()
+        headers['content-type'] = 'application/json'
+
+        return self.client.request(method,
+                                   url=url,
+                                   params=request.params,
+                                   headers=headers,
+                                   data=request.content)

setup.cfg

@@ -29,6 +29,10 @@ setup-hooks =
 packages =
     marconiclient
 
+[entry_points]
+marconiclient.transport =
+    http.v1 = marconiclient.transport.http:HttpTransport
+
 [nosetests]
 where=tests
 verbosity=2

tests/unit/transport/test_api.py

@@ -15,27 +15,14 @@
 
 from marconiclient import errors
 from marconiclient.tests import base
-from marconiclient.transport import api
+from marconiclient.tests.transport import api as tapi
-
-
-class FakeApi(api.Api):
-    schema = {
-        'test_operation': {
-            'properties': {
-                'name': {'type': 'string'}
-            },
-
-            'additionalProperties': False,
-            'required': ['name']
-        }
-    }
 
 
 class TestApi(base.TestBase):
 
     def setUp(self):
         super(TestApi, self).setUp()
-        self.api = FakeApi()
+        self.api = tapi.FakeApi()
 
     def test_valid_params(self):
         self.assertTrue(self.api.validate('test_operation',

tests/unit/transport/test_http.py

@@ -0,0 +1,78 @@
+# Copyright (c) 2013 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
+
+from marconiclient.tests import base
+from marconiclient.tests.transport import api
+from marconiclient.transport import http
+from marconiclient.transport import request
+
+
+class TestHttpTransport(base.TestBase):
+    """Tests for the HTTP transport."""
+
+    def setUp(self):
+        super(TestHttpTransport, self).setUp()
+        self.api = api.FakeApi()
+        self.transport = http.HttpTransport(self.conf)
+
+    def test_basic_send(self):
+        params = {'name': 'Test',
+                  'address': 'Outer space'}
+        req = request.Request('http://example.org/',
+                              operation='test_operation',
+                              params=params)
+
+        with mock.patch.object(self.transport.client, 'request',
+                               autospec=True) as request_method:
+
+            request_method.return_value = None
+
+            # NOTE(flaper87): Bypass the API
+            # loading step by setting the _api
+            # attribute
+            req._api = self.api
+            self.transport.send(req)
+
+            final_url = 'http://example.org/test/Test'
+            final_params = {'address': 'Outer space'}
+            final_headers = {'content-type': 'application/json'}
+
+            request_method.assert_called_with('GET', url=final_url,
+                                              params=final_params,
+                                              headers=final_headers,
+                                              data=None)
+
+    def test_send_without_api(self):
+        params = {'name': 'Test',
+                  'address': 'Outer space'}
+        req = request.Request('http://example.org/',
+                              operation='test_operation',
+                              params=params)
+
+        with mock.patch.object(self.transport.client, 'request',
+                               autospec=True) as request_method:
+
+            request_method.return_value = None
+            self.transport.send(req)
+
+            final_url = 'http://example.org/'
+            final_headers = {'content-type': 'application/json'}
+
+            request_method.assert_called_with('GET', url=final_url,
+                                              params=params,
+                                              headers=final_headers,
+                                              data=None)