Added support for total on API

Added a generic function to load storage backend
Added storage hooks to API
Added total calculation on backends
Moved NoTimeFrame exception to base code

Change-Id: I917335aaeb01b58c1cbb86ae63b260d3f91a7ba7

cloudkitty/api/app.py

@@ -28,6 +28,7 @@ from cloudkitty.api import hooks
 from cloudkitty.common import rpc
 from cloudkitty import config  # noqa
 from cloudkitty.openstack.common import log as logging
+from cloudkitty import storage
 
 
 LOG = logging.getLogger(__name__)
@@ -70,8 +71,11 @@ def setup_app(pecan_config=None, extra_hooks=None):
 
     client = rpc.get_client(target)
 
+    storage_backend = storage.get_storage()
+
     app_hooks = [
-        hooks.RPCHook(client)
+        hooks.RPCHook(client),
+        hooks.StorageHook(storage_backend),
     ]
 
     return pecan.make_app(

cloudkitty/api/controllers/v1.py

@@ -250,8 +250,12 @@ class ReportController(rest.RestController):
         """Return the amount to pay for the current month.
 
         """
-        # TODO(sheeprine): Get current total from DB
-        return 10.0
+        storage = pecan.request.storage_backend
+        # FIXME(sheeprine): We should filter on user id.
+        # Use keystone token information by default but make it overridable and
+        # enforce it by policy engine
+        total = storage.get_total()
+        return total
 
 
 class V1Controller(rest.RestController):

cloudkitty/api/hooks.py

@@ -24,3 +24,11 @@ class RPCHook(hooks.PecanHook):
 
     def before(self, state):
         state.request.rpc_client = self._rpc_client
+
+
+class StorageHook(hooks.PecanHook):
+    def __init__(self, storage_backend):
+        self._storage_backend = storage_backend
+
+    def before(self, state):
+        state.request.storage_backend = self._storage_backend

cloudkitty/storage/__init__.py

@@ -20,8 +20,9 @@ import datetime
 
 from oslo.config import cfg
 import six
+from stevedore import driver
 
-
+STORAGES_NAMESPACE = 'cloudkitty.storage.backends'
 storage_opts = [
     cfg.StrOpt('backend',
                default='sqlalchemy',
@@ -31,6 +32,25 @@ storage_opts = [
 cfg.CONF.register_opts(storage_opts, group='storage')
 
 
+def get_storage():
+    cfg.CONF.import_opt('period', 'cloudkitty.config', 'collect')
+    storage_args = {'period': cfg.CONF.collect.period}
+    backend = driver.DriverManager(
+        STORAGES_NAMESPACE,
+        cfg.CONF.storage.backend,
+        invoke_on_load=True,
+        invoke_kwds=storage_args).driver
+    return backend
+
+
+class NoTimeFrame(Exception):
+    """Raised when there is no time frame available."""
+
+    def __init__(self):
+        super(NoTimeFrame, self).__init__(
+            "No time frame available")
+
+
 @six.add_metaclass(abc.ABCMeta)
 class BaseStorage(object):
     """Base Storage class:
@@ -103,7 +123,9 @@ class BaseStorage(object):
 
     @abc.abstractmethod
     def get_total(self):
-        pass
+        """Return the current total.
+
+        """
 
     @abc.abstractmethod
     def get_time_frame(self, begin, end, **filters):

cloudkitty/storage/sqlalchemy/__init__.py

@@ -15,9 +15,11 @@
 #
 # @author: Stéphane Albert
 #
+import datetime
 import json
 
 from oslo.db.sqlalchemy import utils
+import sqlalchemy
 
 from cloudkitty import db
 from cloudkitty import storage
@@ -26,14 +28,6 @@ from cloudkitty.storage.sqlalchemy import models
 from cloudkitty import utils as ck_utils
 
 
-class NoTimeFrame(Exception):
-    """Raised when there is no time frame available."""
-
-    def __init__(self):
-        super(NoTimeFrame, self).__init__(
-            "No time frame available")
-
-
 class SQLAlchemyStorage(storage.BaseStorage):
     """SQLAlchemy Storage Backend
 
@@ -73,7 +67,20 @@ class SQLAlchemyStorage(storage.BaseStorage):
             return ck_utils.dt2ts(r.begin)
 
     def get_total(self):
-        pass
+        model = models.RatedDataFrame
+
+        # Boundary calculation
+        month_start = ck_utils.get_this_month()
+        month_end = ck_utils.get_next_month()
+
+        session = db.get_session()
+        rate = session.query(
+            sqlalchemy.func.sum(model.rate).label('rate')
+        ).filter(
+            model.begin >= month_start,
+            model.end <= month_end
+        ).scalar()
+        return rate
 
     def get_time_frame(self, begin, end, **filters):
         """Return a list of time frames.
@@ -89,14 +96,15 @@ class SQLAlchemyStorage(storage.BaseStorage):
             model,
             session
         ).filter(
-            model.begin >= begin,
-            model.end <= end
+            model.begin >= datetime.datetime.fromtimestamp(begin),
+            model.end <= datetime.datetime.fromtimestamp(end)
         )
         for cur_filter in filters:
             q = q.filter(getattr(model, cur_filter) == filters[cur_filter])
-        if not q:
-            raise NoTimeFrame()
-        return q.to_cloudkitty()
+        r = q.all()
+        if not r:
+            raise storage.NoTimeFrame()
+        return [entry.to_cloudkitty() for entry in r]
 
     def _append_time_frame(self, res_type, frame):
         vol_dict = frame['vol']