Add connectivity test via 2 routers and tenant networks

This patch adds test to check if connectivity through 2 routers
and internal network between routers works fine.

When at least two compute nodes are available for tempest and
DifferentHostFilter is enabled in nova-scheduler VM1 and VM2 will be
spawned on two different compute nodes.

Connectivity scenario in test is like on picture below:

	    +-----+
	    | VM 1|
	    +--+--+
	       |
	       | Network 1 (tenant network)
	       |
	     +-+-+
	     | R1|
	     +-+-+
	       |
	       | Network 3 (tenant network)
	       |
	     +-+-+
	     | R2|
	     +-+-+
	       |
	       | Network 2 (tenant network)
	       |
	    +--+--+
	    | VM 2|
	    +-----+

Depends-On: https://review.openstack.org/597567
Change-Id: Ie9903b7078d6fcff307c5d76770d92df1152d473
Related-Bug: #1786272
diff --git a/neutron_tempest_plugin/scenario/test_connectivity.py b/neutron_tempest_plugin/scenario/test_connectivity.py
new file mode 100644
index 0000000..3385a04
--- /dev/null
+++ b/neutron_tempest_plugin/scenario/test_connectivity.py
@@ -0,0 +1,111 @@
+# Copyright 2018 Red Hat, Inc.
+# All Rights Reserved.
+#
+#    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 tempest.common import compute
+from tempest.common import utils
+from tempest.lib.common.utils import data_utils
+from tempest.lib import decorators
+
+from neutron_tempest_plugin.common import ssh
+from neutron_tempest_plugin import config
+from neutron_tempest_plugin.scenario import base
+
+CONF = config.CONF
+
+
+class NetworkConnectivityTest(base.BaseTempestTestCase):
+    credentials = ['primary', 'admin']
+
+    @classmethod
+    @utils.requires_ext(extension="router", service="network")
+    def resource_setup(cls):
+        super(NetworkConnectivityTest, cls).resource_setup()
+        # Create keypair with admin privileges
+        cls.keypair = cls.create_keypair()
+        # Create security group with admin privileges
+        cls.secgroup = cls.create_security_group(
+            name=data_utils.rand_name('secgroup'))
+        # Execute funcs to achieve ssh and ICMP capabilities
+        cls.create_loginable_secgroup_rule(secgroup_id=cls.secgroup['id'])
+        cls.create_pingable_secgroup_rule(secgroup_id=cls.secgroup['id'])
+
+    def _create_servers(self, port_1, port_2):
+        params = {
+            'flavor_ref': CONF.compute.flavor_ref,
+            'image_ref': CONF.compute.image_ref,
+            'key_name': self.keypair['name']
+        }
+        vm1 = self.create_server(networks=[{'port': port_1['id']}], **params)
+
+        if (CONF.compute.min_compute_nodes > 1 and
+                compute.is_scheduler_filter_enabled("DifferentHostFilter")):
+            params['scheduler_hints'] = {
+                'different_host': [vm1['server']['id']]}
+
+        self.create_server(networks=[{'port': port_2['id']}], **params)
+
+    @decorators.idempotent_id('8944b90d-1766-4669-bd8a-672b5d106bb7')
+    def test_connectivity_through_2_routers(self):
+        ap1_net = self.create_network()
+        ap2_net = self.create_network()
+        wan_net = self.create_network()
+        ap1_subnet = self.create_subnet(
+            ap1_net, cidr="10.10.210.0/24", gateway="10.10.210.254")
+        ap2_subnet = self.create_subnet(
+            ap2_net, cidr="10.10.220.0/24", gateway="10.10.220.254")
+        self.create_subnet(
+            wan_net, cidr="10.10.200.0/24", gateway="10.10.200.254")
+
+        ap1_rt = self.create_router(
+            router_name=data_utils.rand_name("ap1_rt"),
+            admin_state_up=True,
+            external_network_id=CONF.network.public_network_id)
+        ap2_rt = self.create_router(
+            router_name=data_utils.rand_name("ap2_rt"),
+            admin_state_up=True)
+
+        ap1_internal_port = self.create_port(
+            ap1_net, security_groups=[self.secgroup['id']])
+        ap2_internal_port = self.create_port(
+            ap2_net, security_groups=[self.secgroup['id']])
+        ap1_wan_port = self.create_port(wan_net)
+        ap2_wan_port = self.create_port(wan_net)
+
+        self._create_servers(ap1_internal_port, ap2_internal_port)
+
+        self.client.add_router_interface_with_port_id(
+            ap1_rt['id'], ap1_wan_port['id'])
+        self.client.add_router_interface_with_port_id(
+            ap2_rt['id'], ap2_wan_port['id'])
+        self.create_router_interface(ap1_rt['id'], ap1_subnet['id'])
+        self.create_router_interface(ap2_rt['id'], ap2_subnet['id'])
+
+        self.client.update_router(
+            ap1_rt['id'],
+            routes=[{"destination": ap2_subnet['cidr'],
+                     "nexthop": ap2_wan_port['fixed_ips'][0]['ip_address']}])
+        self.client.update_router(
+            ap2_rt['id'],
+            routes=[{"destination": ap1_subnet['cidr'],
+                     "nexthop": ap1_wan_port['fixed_ips'][0]['ip_address']}])
+
+        ap1_fip = self.create_and_associate_floatingip(
+            ap1_internal_port['id'])
+        ap1_sshclient = ssh.Client(
+            ap1_fip['floating_ip_address'], CONF.validation.image_ssh_user,
+            pkey=self.keypair['private_key'])
+
+        self.check_remote_connectivity(
+            ap1_sshclient, ap2_internal_port['fixed_ips'][0]['ip_address'])