Change api.service to use a class, fix validations in api

Change-Id: Ib5a957a82238b18548ff470ea9c2905b389d026e

climate/api/service.py

@@ -19,53 +19,50 @@ from climate.openstack.common import log as logging
 LOG = logging.getLogger(__name__)
 
 
-## Leases operations
+class API(object):
 
-def get_leases():
-    """List all existing leases."""
-    pass
+    ## Leases operations
 
+    def get_leases():
+        """List all existing leases."""
+        pass
 
-def create_lease(data):
-    """Create new lease.
+    def create_lease(data):
+        """Create new lease.
 
-    :param data: New lease characteristics.
-    :type data: dict
-    """
-    pass
+        :param data: New lease characteristics.
+        :type data: dict
+        """
+        pass
 
+    def get_lease(lease_id):
+        """Get lease by its ID.
 
-def get_lease(lease_id):
-    """Get lease by its ID.
+        :param lease_id: ID of the lease in Climate DB.
+        :type lease_id: str
+        """
+        pass
 
-    :param lease_id: ID of the lease in Climate DB.
-    :type lease_id: str
-    """
-    pass
+    def update_lease(lease_id, data):
+        """Update lease. Only name changing and prolonging may be proceeded.
 
+        :param lease_id: ID of the lease in Climate DB.
+        :type lease_id: str
+        :param data: New lease characteristics.
+        :type data: dict
+        """
+        pass
 
-def update_lease(lease_id, data):
-    """Update lease. Only name changing and prolonging may be proceeded.
+    def delete_lease(lease_id):
+        """Delete specified lease.
 
-    :param lease_id: ID of the lease in Climate DB.
-    :type lease_id: str
-    :param data: New lease characteristics.
-    :type data: dict
-    """
-    pass
+        :param lease_id: ID of the lease in Climate DB.
+        :type lease_id: str
+        """
+        pass
 
+    ## Plugins operations
 
-def delete_lease(lease_id):
-    """Delete specified lease.
-
-    :param lease_id: ID of the lease in Climate DB.
-    :type lease_id: str
-    """
-    pass
-
-
-## Plugins operations
-
-def get_plugins():
-    """List all possible plugins."""
-    pass
+    def get_plugins():
+        """List all possible plugins."""
+        pass

climate/api/v1_0.py

@@ -17,10 +17,12 @@ from climate.api import service
 from climate.api import utils as api_utils
 from climate.api import validation
 from climate.openstack.common import log as logging
+from climate import utils
 
 LOG = logging.getLogger(__name__)
 
 rest = api_utils.Rest('v1_0', __name__)
+_api = utils.LazyProxy(service.API)
 
 
 ## Leases operations
@@ -28,34 +30,34 @@ rest = api_utils.Rest('v1_0', __name__)
 @rest.get('/leases')
 def leases_list():
     """List all existing leases."""
-    return api_utils.render(leases=service.get_leases())
+    return api_utils.render(leases=_api.get_leases())
 
 
 @rest.post('/leases')
 def leases_create(data):
     """Create new lease."""
-    return api_utils.render(lease=service.create_lease(data))
+    return api_utils.render(lease=_api.create_lease(data))
 
 
 @rest.get('/leases/<lease_id>')
-@validation.check_exists(service.get_lease, 'lease_id')
+@validation.check_exists(_api.get_lease, lease_id='lease_id')
 def leases_get(lease_id):
     """Get lease by its ID."""
-    return api_utils.render(lease=service.get_lease(lease_id))
+    return api_utils.render(lease=_api.get_lease(lease_id))
 
 
 @rest.put('/leases/<lease_id>')
-@validation.check_exists(service.get_lease, 'lease_id')
+@validation.check_exists(_api.get_lease, lease_id='lease_id')
 def leases_update(lease_id, data):
     """Update lease. Only name changing and prolonging may be proceeded."""
-    return api_utils.render(lease=service.update_lease(lease_id, data))
+    return api_utils.render(lease=_api.update_lease(lease_id, data))
 
 
 @rest.delete('/leases/<lease_id>')
-@validation.check_exists(service.get_lease, 'lease_id')
+@validation.check_exists(_api.get_lease, lease_id='lease_id')
 def leases_delete(lease_id):
     """Delete specified lease."""
-    service.delete_lease(lease_id)
+    _api.delete_lease(lease_id)
     return api_utils.render()
 
 
@@ -64,4 +66,4 @@ def leases_delete(lease_id):
 @rest.get('/plugins')
 def plugins_list():
     """List all possible plugins."""
-    return api_utils.render(plugins=service.get_plugins())
+    return api_utils.render(plugins=_api.get_plugins())

climate/utils/__init__.py

@@ -12,3 +12,21 @@
 # implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+import functools
+
+
+class LazyProxy(object):
+
+    def __init__(self, klass, *args, **kwargs):
+        self.klass = klass
+        self.args = args
+        self.kwargs = kwargs
+        self.instance = None
+
+    def __getattr__(self, name):
+        return functools.partial(self.__run_method, name)
+
+    def __run_method(self, __name, *args, **kwargs):
+        if self.instance is None:
+            self.instance = self.klass(*self.args, **self.kwargs)
+        return getattr(self.instance, __name)(*args, **kwargs)