Add support for flavor to the client library

This patch adds support for flavors to the client library. Flavors are
an admin endpoint, which means pool's rules apply to them.

Since flavors were added since 1.1, this patch also adds a version
decorator that will help making sure features are accessible just if the
api_version the client has been instantiated with matches the version
the feature was added into.

Note that the core module does not use the version decorator. There are
2 reasons for this:

    1. Users accessing the core module should know what they're doing
    2. If the transport loads the spec for the API version it was
    instantiated with. If that spec does not contain a specific action,
    the whole operation will fail before hitting the wire.

Partially-Implements blueprint: api-v1.1

Change-Id: I92dbe417655a9eeefb030481a81a67840a63dd0e

tests/functional/queues/v1/test_flavor.py

@@ -0,0 +1,27 @@
+# Copyright (c) 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.
+
+
+from zaqarclient.tests.queues import flavor
+from zaqarclient.transport import http
+
+
+class QueuesV1_1FlavorHttpFunctionalTest(
+        flavor.QueuesV1_1FlavorFunctionalTest):
+
+    is_functional = True
+    transport_cls = http.HttpTransport
+    url = 'http://127.0.0.1:8888/v1.1'
+    version = 1.1

tests/unit/queues/v1/test_flavor.py

@@ -0,0 +1,25 @@
+# Copyright (c) 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.
+
+
+from zaqarclient.tests.queues import flavor
+from zaqarclient.transport import http
+
+
+class QueuesV1_1FlavorHttpUnitTest(flavor.QueuesV1_1FlavorUnitTest):
+
+    transport_cls = http.HttpTransport
+    url = 'http://127.0.0.1:8888/v1.1'
+    version = 1.1

zaqarclient/common/decorators.py

@@ -0,0 +1,67 @@
+# 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 functools
+
+from zaqarclient import errors
+
+
+def version(min_version, max_version=None):
+    min_version = float(min_version)
+    max_version = max_version and float(max_version)
+
+    error_msg = ('Method %(name)s is supported from version %(min)s '
+                 'to %(max)s')
+
+    def method(meth):
+        @functools.wraps(meth)
+        def wrapper(self, *args, **kwargs):
+            if (self.api_version < min_version or
+                    (max_version and self.api_version > max_version)):
+                msg = error_msg % dict(name=str(meth),
+                                       min=min_version,
+                                       max=max_version or 'latest')
+                raise errors.UnsupportedVersion(msg)
+            return meth(self, *args, **kwargs)
+        return wrapper
+    return method
+
+
+def lazy_property(write=False, delete=True):
+    """Creates a lazy property.
+
+    :param write: Whether this property is "writable"
+    :param delete: Whether this property can be deleted.
+    """
+
+    def wrapper(fn):
+        attr_name = '_lazy_' + fn.__name__
+
+        def getter(self):
+            if not hasattr(self, attr_name):
+                setattr(self, attr_name, fn(self))
+            return getattr(self, attr_name)
+
+        def setter(self, value):
+            setattr(self, attr_name, value)
+
+        def deleter(self):
+            delattr(self, attr_name)
+
+        return property(fget=getter,
+                        fset=write and setter,
+                        fdel=delete and deleter,
+                        doc=fn.__doc__)
+    return wrapper

zaqarclient/errors.py

@@ -31,3 +31,7 @@ class DriverLoadFailure(ZaqarError):
 
 class InvalidOperation(ZaqarError):
     """Raised when attempted a non existent operation."""
+
+
+class UnsupportedVersion(ZaqarError):
+    """Raised if there is no endpoint which supports the requested version."""

zaqarclient/queues/v1/api.py

@@ -172,6 +172,24 @@ class V1(api.Api):
             }
         },
 
+        'flavor_create': {
+            'ref': 'flavors/{flavor_name}',
+            'method': 'PUT',
+            'required': ['flavor_name'],
+            'properties': {
+                'flavor_name': {'type': 'string'},
+            }
+        },
+
+        'flavor_delete': {
+            'ref': 'flavors/{flavor_name}',
+            'method': 'DELETE',
+            'required': ['flavor_name'],
+            'properties': {
+                'flavor_name': {'type': 'string'},
+            }
+        },
+
         'claim_create': {
             'ref': 'queues/{queue_name}/claims',
             'method': 'POST',

zaqarclient/queues/v1/client.py

@@ -16,7 +16,9 @@
 import uuid
 import warnings
 
+from zaqarclient.common import decorators
 from zaqarclient.queues.v1 import core
+from zaqarclient.queues.v1 import flavor
 from zaqarclient.queues.v1 import iterator
 from zaqarclient.queues.v1 import pool
 from zaqarclient.queues.v1 import queues
@@ -136,6 +138,18 @@ class Client(object):
         """
         return pool.Pool(self, ref, **kwargs)
 
+    @decorators.version(min_version=1.1)
+    def flavor(self, ref, **kwargs):
+        """Returns a flavor instance
+
+        :param ref: Flavor's reference name.
+        :type ref: `six.text_type`
+
+        :returns: A flavor instance
+        :rtype: `flavor.Flavor`
+        """
+        return flavor.Flavor(self, ref, **kwargs)
+
     def health(self):
         """Gets the health status of Zaqar server."""
         req, trans = self._request_and_transport()

zaqarclient/queues/v1/core.py

@@ -433,6 +433,41 @@ def pool_delete(transport, request, pool_name):
     transport.send(request)
 
 
+def flavor_create(transport, request, name, flavor_data):
+    """Creates a flavor called `name`
+
+    :param transport: Transport instance to use
+    :type transport: `transport.base.Transport`
+    :param request: Request instance ready to be sent.
+    :type request: `transport.request.Request`
+    :param name: Flavor reference name.
+    :type name: `six.text_type`
+    :param flavor_data: Flavor's properties, i.e: pool, capabilities.
+    :type flavor_data: `dict`
+    """
+
+    request.operation = 'flavor_create'
+    request.params['flavor_name'] = name
+    request.content = json.dumps(flavor_data)
+    transport.send(request)
+
+
+def flavor_delete(transport, request, name):
+    """Deletes the flavor `name`
+
+    :param transport: Transport instance to use
+    :type transport: `transport.base.Transport`
+    :param request: Request instance ready to be sent.
+    :type request: `transport.request.Request`
+    :param name: Flavor reference name.
+    :type name: `six.text_type`
+    """
+
+    request.operation = 'flavor_delete'
+    request.params['flavor_name'] = name
+    transport.send(request)
+
+
 def health(transport, request, callback=None):
     """Check the health of web head for load balancing
 

zaqarclient/queues/v1/flavor.py

@@ -0,0 +1,48 @@
+# Copyright (c) 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.
+
+from zaqarclient.queues.v1 import core
+
+
+class Flavor(object):
+
+    def __init__(self, client, name,
+                 pool, auto_create=True, **capabilities):
+        self.client = client
+
+        self.name = name
+        self.pool = pool
+        self.capabilities = capabilities
+
+        if auto_create:
+            self.ensure_exists()
+
+    def ensure_exists(self):
+        """Ensures pool exists
+
+        This method is not race safe,
+        the pool could've been deleted
+        right after it was called.
+        """
+        req, trans = self.client._request_and_transport()
+
+        data = {'pool': self.pool,
+                'capabilities': self.capabilities}
+
+        core.flavor_create(trans, req, self.name, data)
+
+    def delete(self):
+        req, trans = self.client._request_and_transport()
+        core.flavor_delete(trans, req, self.name)

zaqarclient/tests/queues/flavor.py

@@ -0,0 +1,85 @@
+# Copyright (c) 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
+
+from zaqarclient.tests.queues import base
+from zaqarclient.transport import response
+
+
+class QueuesV1_1FlavorUnitTest(base.QueuesTestBase):
+
+    url = 'http://127.0.0.1:8888/v1.1'
+    version = 1.1
+
+    def test_flavor_create(self):
+        flavor_data = {'pool': 'stomach'}
+
+        with mock.patch.object(self.transport, 'send',
+                               autospec=True) as send_method:
+
+            resp = response.Response(None, None)
+            send_method.return_value = resp
+
+            # NOTE(flaper87): This will call
+            # ensure exists in the client instance
+            # since auto_create's default is True
+            flavor = self.client.flavor('tasty', **flavor_data)
+            self.assertEqual(flavor.name, 'tasty')
+            self.assertEqual(flavor.pool, 'stomach')
+
+    def test_flavor_delete(self):
+        flavor_data = {'pool': 'stomach'}
+
+        with mock.patch.object(self.transport, 'send',
+                               autospec=True) as send_method:
+
+            resp = response.Response(None, None)
+            send_method.return_value = resp
+
+            # NOTE(flaper87): This will call
+            # ensure exists in the client instance
+            # since auto_create's default is True
+            flavor = self.client.flavor('tasty', **flavor_data)
+            flavor.delete()
+
+            # NOTE(flaper87): Nothing to assert here,
+            # just checking our way down to the transport
+            # doesn't crash.
+
+
+class QueuesV1_1FlavorFunctionalTest(base.QueuesTestBase):
+
+    url = 'http://127.0.0.1:8888/v1.1'
+    version = 1.1
+
+    def test_flavor_create(self):
+        pool_data = {'uri': 'sqlite://',
+                     'weight': 10}
+        self.client.pool('stomach', **pool_data)
+
+        flavor_data = {'pool': 'stomach'}
+        flavor = self.client.flavor('tasty', **flavor_data)
+        self.assertEqual(flavor.name, 'tasty')
+        self.assertEqual(flavor.pool, 'stomach')
+
+    def test_flavor_delete(self):
+        pool_data = {'uri': 'sqlite://',
+                     'weight': 10}
+        self.client.pool('stomach', **pool_data)
+
+        flavor_data = {'pool': 'stomach'}
+        flavor = self.client.flavor('tasty', **flavor_data)
+        flavor.delete()