Creating individual resources for vpnaas test case

As per design there is only one vpn-service object per router.
Tempest test cases were failing due to creation of multiple
vpn service object for the same single router by raising an
router in use execption.so creating individual resources for
each test cases.

Closes-Bug: 1376104

Change-Id: Id327488c039374160bbfaa9705b869a38aa0583c
diff --git a/tempest/api/network/test_vpnaas_extensions.py b/tempest/api/network/test_vpnaas_extensions.py
index c61bf41..96b9804 100644
--- a/tempest/api/network/test_vpnaas_extensions.py
+++ b/tempest/api/network/test_vpnaas_extensions.py
@@ -39,6 +39,7 @@
             msg = "vpnaas extension not enabled."
             raise cls.skipException(msg)
         super(VPNaaSTestJSON, cls).resource_setup()
+        cls.ext_net_id = CONF.network.public_network_id
         cls.network = cls.create_network()
         cls.subnet = cls.create_subnet(cls.network)
         cls.router = cls.create_router(
@@ -121,17 +122,21 @@
         tenant_id = self._get_tenant_id()
 
         # Create vpn service for the newly created tenant
+        network2 = self.create_network()
+        subnet2 = self.create_subnet(network2)
+        router2 = self.create_router(data_utils.rand_name('router-'),
+                                     external_network_id=self.ext_net_id)
+        self.create_router_interface(router2['id'], subnet2['id'])
         name = data_utils.rand_name('vpn-service')
         _, body = self.admin_client.create_vpnservice(
-            subnet_id=self.subnet['id'],
-            router_id=self.router['id'],
+            subnet_id=subnet2['id'],
+            router_id=router2['id'],
             name=name,
             admin_state_up=True,
             tenant_id=tenant_id)
         vpnservice = body['vpnservice']
         self.assertIsNotNone(vpnservice['id'])
         self.addCleanup(self.admin_client.delete_vpnservice, vpnservice['id'])
-
         # Assert that created vpnservice is found in API list call
         _, body = self.client.list_vpnservices()
         vpn_services = [vs['id'] for vs in body['vpnservices']]
@@ -167,9 +172,14 @@
     @test.attr(type='smoke')
     def test_create_update_delete_vpn_service(self):
         # Creates a VPN service and sets up deletion
-        name = data_utils.rand_name('vpn-service')
-        _, body = self.client.create_vpnservice(subnet_id=self.subnet['id'],
-                                                router_id=self.router['id'],
+        network1 = self.create_network()
+        subnet1 = self.create_subnet(network1)
+        router1 = self.create_router(data_utils.rand_name('router-'),
+                                     external_network_id=self.ext_net_id)
+        self.create_router_interface(router1['id'], subnet1['id'])
+        name = data_utils.rand_name('vpn-service1')
+        _, body = self.client.create_vpnservice(subnet_id=subnet1['id'],
+                                                router_id=router1['id'],
                                                 name=name,
                                                 admin_state_up=True)
         vpnservice = body['vpnservice']