[API] Support per-tenant max loadbalancers

Note: Schema altering change

Adds a new table that allows maximum number of load balancers to
be set per tenant ID. If a value is not set, the global value is
used. The per-tenant value always overrides the global value.

Change-Id: Ib7911742510756e34a4ef0ecf9380abb2a759e8e

libra/api/controllers/limits.py

@@ -13,20 +13,32 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-from pecan import expose
+from pecan import expose, request
 from pecan.rest import RestController
-from libra.common.api.lbaas import Limits, db_session
+from libra.api.acl import get_limited_to_project
+from libra.common.api.lbaas import Limits, TenantLimits, db_session
 
 
 class LimitsController(RestController):
     @expose('json')
     def get(self):
         resp = {}
+        tenant_id = get_limited_to_project(request.headers)
+
         with db_session() as session:
             limits = session.query(Limits).all()
+
+            # Get per-tenant values
+            tenant_lblimit = session.query(TenantLimits.loadbalancers).\
+                filter(TenantLimits.tenantid == tenant_id).scalar()
+
             for limit in limits:
                 resp[limit.name] = limit.value
 
+            # Set per-tenant values
+            if tenant_lblimit:
+                resp['maxLoadBalancers'] = tenant_lblimit
+
             resp = {"limits": {"absolute": {"values": resp}}}
             session.rollback()
             return resp

libra/api/controllers/load_balancers.py

@@ -28,6 +28,7 @@ from logs import LogsController
 # models
 from libra.common.api.lbaas import LoadBalancer, Device, Node, db_session
 from libra.common.api.lbaas import loadbalancers_devices, Limits, Vip
+from libra.common.api.lbaas import TenantLimits
 from libra.common.api.lbaas import HealthMonitor
 from libra.common.exc import ExhaustedError
 from libra.api.model.validators import LBPut, LBPost, LBResp, LBVipResp
@@ -267,6 +268,13 @@ class LoadBalancersController(RestController):
                 filter(LoadBalancer.tenantid == tenant_id).\
                 filter(LoadBalancer.status != 'DELETED').count()
 
+            # Allow per-tenant LB limit, defaulting to the global limit if
+            # the per-tenant value is not set.
+            tenant_lblimit = session.query(TenantLimits.loadbalancers).\
+                filter(TenantLimits.tenantid == tenant_id).scalar()
+            if tenant_lblimit:
+                lblimit = tenant_lblimit
+
             if len(body.name) > namelimit:
                 session.rollback()
                 raise ClientSideError(

libra/common/api/lbaas.py

@@ -50,6 +50,13 @@ class FormatedDateTime(types.TypeDecorator):
         return value.strftime('%Y-%m-%dT%H:%M:%S')
 
 
+class TenantLimits(DeclarativeBase):
+    __tablename__ = 'tenant_limits'
+    id = Column(u'id', Integer, primary_key=True, nullable=False)
+    tenantid = Column(u'tenantid', VARCHAR(length=128), nullable=False)
+    loadbalancers = Column(u'loadbalancers', INTEGER(), nullable=True)
+
+
 class Limits(DeclarativeBase):
     __tablename__ = 'global_limits'
     id = Column(u'id', Integer, primary_key=True, nullable=False)

libra/common/api/lbaas.sql

@@ -100,6 +100,14 @@ CREATE TABLE `global_limits` (
 
 INSERT INTO `global_limits` VALUES (1,'maxLoadBalancerNameLength',128),(2,'maxVIPsPerLoadBalancer',1),(3,'maxNodesPerLoadBalancer',50),(4,'maxLoadBalancers',20);
 
+CREATE TABLE `tenant_limits` (
+  `id` int(11) NOT NULL AUTO_INCREMENT,
+  `tenantid` VARCHAR(128) NOT NULL,
+  `loadbalancers` INT,                     # Max number of load balancers
+  PRIMARY KEY(id),
+  UNIQUE KEY `tenantid` (`tenantid`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1;
+
 # Billing
 CREATE TABLE billing (
     id           int(11)             NOT NULL,
@@ -120,4 +128,3 @@ CREATE TABLE stats (
     status         VARCHAR(50)              NOT NULL,                              # Current LB status
     PRIMARY KEY (id)                                                               # ids are unique across all LBs
  ) ENGINE=InnoDB DEFAULT CHARSET latin1;
-