Gets 'pool' data if the resource exists

Pool instances can be created by just passing the name. They both
check at construction time whether the resource exist in the server or
not. If the resource doesn't exist, it'll attempt to create one.

Zaqarclient does not call anymore the 'pool_create' directly. It calls
'pool_get' first, which ensures the resource exists. if not, a 'pool'
will be created.

Change-Id: I8f18b5031c80cfd5744ba3b0b7058654934f44b4
Partial-Bug: #1396063

tests/unit/queues/v1/test_core.py

@@ -221,6 +221,16 @@ class TestV1Core(base.TestBase):
                              'test_pool', {'uri': 'sqlite://',
                                            'weight': 0})
 
+    def test_pool_get(self):
+        with mock.patch.object(self.transport, 'send',
+                               autospec=True) as send_method:
+            resp = response.Response(None, None)
+            send_method.return_value = resp
+
+            req = request.Request()
+            core.pool_get(self.transport, req,
+                          'test_pool')
+
     def test_pool_delete(self):
         with mock.patch.object(self.transport, 'send',
                                autospec=True) as send_method:

zaqarclient/queues/v1/api.py

@@ -163,6 +163,15 @@ class V1(api.Api):
             }
         },
 
+        'pool_get': {
+            'ref': 'pools/{pool_name}',
+            'method': 'GET',
+            'required': ['pool_name'],
+            'properties': {
+                'pool_name': {'type': 'string'},
+            }
+        },
+
         'pool_delete': {
             'ref': 'pools/{pool_name}',
             'method': 'DELETE',

zaqarclient/queues/v1/core.py

@@ -418,6 +418,25 @@ def shard_delete(transport, request, pool_name):
     return pool_delete(transport, request, pool_name)
 
 
+def pool_get(transport, request, pool_name, callback=None):
+    """Gets pool data
+
+    :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 pool_name: Pool reference name.
+    :type pool_name: `six.text_type`
+
+    """
+
+    request.operation = 'pool_get'
+    request.params['pool_name'] = pool_name
+
+    resp = transport.send(request)
+    return resp.deserialized_content
+
+
 def pool_create(transport, request, pool_name, pool_data):
     """Creates a pool called `pool_name`
 

zaqarclient/queues/v1/pool.py

@@ -14,6 +14,7 @@
 # limitations under the License.
 
 from zaqarclient.queues.v1 import core
+from zaqarclient.transport import errors
 
 
 class Pool(object):
@@ -40,11 +41,18 @@ class Pool(object):
         """
         req, trans = self.client._request_and_transport()
 
-        data = {'uri': self.uri,
-                'weight': self.weight,
-                'options': self.options}
+        try:
+            pool = core.pool_get(trans, req, self.name)
+            self.uri = pool["uri"]
+            self.weight = pool["weight"]
+            self.options = pool.get("options", {})
 
-        core.pool_create(trans, req, self.name, data)
+        except errors.ResourceNotFound:
+            data = {'uri': self.uri,
+                    'weight': self.weight,
+                    'options': self.options}
+
+            core.pool_create(trans, req, self.name, data)
 
     def delete(self):
         req, trans = self.client._request_and_transport()

zaqarclient/tests/queues/pool.py

@@ -13,9 +13,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import json
 import mock
 
 from zaqarclient.tests.queues import base
+from zaqarclient.transport import errors
 from zaqarclient.transport import response
 
 
@@ -29,7 +31,7 @@ class QueuesV1PoolUnitTest(base.QueuesTestBase):
                                autospec=True) as send_method:
 
             resp = response.Response(None, None)
-            send_method.return_value = resp
+            send_method.side_effect = iter([errors.ResourceNotFound, resp])
 
             # NOTE(flaper87): This will call
             # ensure exists in the client instance
@@ -38,16 +40,35 @@ class QueuesV1PoolUnitTest(base.QueuesTestBase):
             self.assertEqual(pool.name, 'test')
             self.assertEqual(pool.weight, 10)
 
+    def test_pool_get(self):
+        pool_data = {'weight': 10,
+                     'uri': 'sqlite://',
+                     'options': {}}
+
+        with mock.patch.object(self.transport, 'send',
+                               autospec=True) as send_method:
+
+            resp = response.Response(None, json.dumps(pool_data))
+            send_method.return_value = resp
+
+            # NOTE(flaper87): This will call
+            # ensure exists in the client instance
+            # since auto_create's default is True
+            pool = self.client.pool('test')
+            self.assertEqual(pool.name, 'test')
+            self.assertEqual(pool.weight, 10)
+
     def test_pool_delete(self):
         pool_data = {'weight': 10,
-                     'uri': 'sqlite://'}
+                     'uri': 'sqlite://',
+                     'options': {}}
 
         with mock.patch.object(self.transport, 'send',
                                autospec=True) as send_method:
 
             resp = response.Response(None, None)
-            send_method.return_value = resp
-
+            resp_data = response.Response(None, json.dumps(pool_data))
+            send_method.side_effect = iter([resp_data, resp])
             # NOTE(flaper87): This will call
             # ensure exists in the client instance
             # since auto_create's default is True
@@ -61,6 +82,16 @@ class QueuesV1PoolUnitTest(base.QueuesTestBase):
 
 class QueuesV1PoolFunctionalTest(base.QueuesTestBase):
 
+    def test_pool_get(self):
+        pool_data = {'weight': 10,
+                     'uri': 'sqlite://'}
+
+        self.client.pool('test', **pool_data)
+        pool = self.client.pool('test')
+        self.assertEqual(pool.name, 'test')
+        self.assertEqual(pool.weight, 10)
+        self.assertEqual(pool.uri, 'sqlite://')
+
     def test_pool_create(self):
         pool_data = {'weight': 10,
                      'uri': 'sqlite://'}

zaqarclient/transport/request.py

@@ -46,7 +46,6 @@ def prepare_request(auth_opts=None, data=None, **kwargs):
     # TODO(flaper87): Do something smarter
     # to get the api_version.
     req = auth_backend.authenticate(1, req)
-
     req.headers['X-Project-Id'] = auth_opts.get('options',
                                                 {}).get('os_project_id')