Add clients module to Tacker

We are invoking individual openstack clients everytime
we need it. But we need a generic openstack clients module
for code resuability. This patch does that by creating new clients.py
file in tacker/common.

Change-Id: Ibe06ff2eafa00b2825d5f412620cb4d051626164
Closes-Bug: #1518244

tacker/common/clients.py

@@ -0,0 +1,69 @@
+# 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 heatclient import client as heatclient
+from keystoneclient.v2_0 import client as ks_client
+from oslo_config import cfg
+from oslo_log import log as logging
+
+LOG = logging.getLogger(__name__)
+CONF = cfg.CONF
+
+OPTS = [
+    cfg.StrOpt('heat_uri',
+        default='http://localhost:8004/v1',
+        help=_("Heat service URI to create VNF resources"
+               "specified in the VNFD templates")),
+]
+CONF.register_opts(OPTS, group='servicevm_heat')
+
+
+class OpenstackClients(object):
+
+    def __init__(self):
+        super(OpenstackClients, self).__init__()
+        self.keystone_client = None
+        self.heat_client = None
+        self.nova_client = None
+        self.auth_url = CONF.keystone_authtoken.auth_uri + '/v2.0'
+        self.auth_username = CONF.keystone_authtoken.username
+        self.auth_password = CONF.keystone_authtoken.password
+        self.auth_tenant_name = CONF.keystone_authtoken.project_name
+
+    def _keystone_client(self):
+        return ks_client.Client(
+                   tenant_name=self.auth_tenant_name,
+                   username=self.auth_username,
+                   password=self.auth_password,
+                   auth_url=self.auth_url)
+
+    def _heat_client(self):
+        tenant_id = self.auth_token['tenant_id']
+        token = self.auth_token['id']
+        endpoint = CONF.servicevm_heat.heat_uri + '/' + tenant_id
+        return heatclient.Client('1', endpoint=endpoint, token=token)
+
+    @property
+    def auth_token(self):
+        return self.keystone.service_catalog.get_token()
+
+    @property
+    def keystone(self):
+        if not self.keystone_client:
+            self.keystone_client = self._keystone_client()
+        return self.keystone_client
+
+    @property
+    def heat(self):
+        if not self.heat_client:
+            self.heat_client = self._heat_client()
+        return self.heat_client

tacker/vm/drivers/heat/heat.py

@@ -20,12 +20,11 @@ import sys
 import time
 import yaml
 
-from heatclient import client as heat_client
 from heatclient import exc as heatException
-from keystoneclient.v2_0 import client as ks_client
 from oslo_config import cfg
 from toscaparser.utils import yamlparser
 
+from tacker.common import clients
 from tacker.common import log
 from tacker.extensions import vnfm
 from tacker.openstack.common import jsonutils
@@ -36,10 +35,6 @@ from tacker.vm.drivers import abstract_driver
 LOG = logging.getLogger(__name__)
 CONF = cfg.CONF
 OPTS = [
-    cfg.StrOpt('heat_uri',
-               default='http://localhost:8004/v1',
-               help=_("Heat server address to create services "
-                      "specified in the service chain.")),
     cfg.IntOpt('stack_retries',
                default=10,
                help=_("Number of attempts to retry for stack deletion")),
@@ -454,25 +449,7 @@ class DeviceHeat(abstract_driver.DeviceAbstractDriver):
 class HeatClient:
     def __init__(self, context, password=None):
         # context, password are unused
-        auth_url = CONF.keystone_authtoken.auth_uri + '/v2.0'
-        authtoken = CONF.keystone_authtoken
-        kc = ks_client.Client(
-            tenant_name=authtoken.project_name,
-            username=authtoken.username,
-            password=authtoken.password,
-            auth_url=auth_url)
-        token = kc.service_catalog.get_token()
-
-        api_version = "1"
-        endpoint = "%s/%s" % (cfg.CONF.servicevm_heat.heat_uri,
-                              token['tenant_id'])
-        kwargs = {
-            'token': token['id'],
-            'tenant_name': authtoken.project_name,
-            'username': authtoken.username,
-        }
-        self.client = heat_client.Client(api_version, endpoint, **kwargs)
-        self.stacks = self.client.stacks
+        self.stacks = clients.OpenstackClients().heat.stacks
 
     def create(self, fields):
         fields = fields.copy()

tacker/vm/monitor.py

@@ -24,10 +24,10 @@ import six
 import threading
 import time
 
-from keystoneclient.v2_0 import client as ks_client
 from oslo_config import cfg
 from oslo_utils import timeutils
 
+from tacker.common import clients
 from tacker.common import driver_manager
 from tacker import context as t_context
 from tacker.openstack.common import jsonutils
@@ -228,14 +228,8 @@ class ActionRespawn(ActionPolicy):
             LOG.debug(_('new_device %s'), new_device)
 
             # keystone v2.0 specific
-            auth_url = CONF.keystone_authtoken.auth_uri + '/v2.0'
             authtoken = CONF.keystone_authtoken
-            kc = ks_client.Client(
-                tenant_name=authtoken.project_name,
-                username=authtoken.username,
-                password=authtoken.password,
-                auth_url=auth_url)
-            token = kc.service_catalog.get_token()
+            token = clients.OpenstackClients().auth_token
 
             context = t_context.get_admin_context()
             context.tenant_name = authtoken.project_name
@@ -284,14 +278,8 @@ class ActionRespawnHeat(ActionPolicy):
             time.sleep(10)
 
             # keystone v2.0 specific
-            auth_url = CONF.keystone_authtoken.auth_uri + '/v2.0'
             authtoken = CONF.keystone_authtoken
-            kc = ks_client.Client(
-                tenant_name=authtoken.project_name,
-                username=authtoken.username,
-                password=authtoken.password,
-                auth_url=auth_url)
-            token = kc.service_catalog.get_token()
+            token = clients.OpenstackClients().auth_token
 
             context = t_context.get_admin_context()
             context.tenant_name = authtoken.project_name