Add logging of servers console in scenario test_port_forwardings

In case when ssh to one of servers in test test_port_forwardings
will fail it is useful to have consile log from servers used in
test.
This patch adds logging of such console output in this test.

Change-Id: I597d2c13544d668f88d78016ff4545e164e97a3e
diff --git a/neutron_tempest_plugin/scenario/test_port_forwardings.py b/neutron_tempest_plugin/scenario/test_port_forwardings.py
index e366d8f..1d1fe94 100644
--- a/neutron_tempest_plugin/scenario/test_port_forwardings.py
+++ b/neutron_tempest_plugin/scenario/test_port_forwardings.py
@@ -13,8 +13,10 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from oslo_log import log
 from tempest.lib.common.utils import data_utils
 from tempest.lib import decorators
+from tempest.lib import exceptions as lib_exc
 
 from neutron_tempest_plugin.common import ssh
 from neutron_tempest_plugin import config
@@ -22,6 +24,8 @@
 
 CONF = config.CONF
 
+LOG = log.getLogger(__name__)
+
 
 class PortForwardingTestJSON(base.BaseTempestTestCase):
 
@@ -66,10 +70,19 @@
                 protocol="tcp")
             servers.append(server)
 
-        for server in servers:
-            ssh_client = ssh.Client(
-                self.fip['floating_ip_address'],
-                CONF.validation.image_ssh_user,
-                pkey=self.keypair['private_key'],
-                port=server['port_forwarding']['external_port'])
-            self.assertIn(server['name'], ssh_client.exec_command('hostname'))
+        try:
+            for server in servers:
+                ssh_client = ssh.Client(
+                    self.fip['floating_ip_address'],
+                    CONF.validation.image_ssh_user,
+                    pkey=self.keypair['private_key'],
+                    port=server['port_forwarding']['external_port'])
+                self.assertIn(server['name'],
+                              ssh_client.exec_command('hostname'))
+        except lib_exc.SSHTimeout as ssh_e:
+            LOG.debug(ssh_e)
+            self._log_console_output(servers)
+            raise
+        except AssertionError:
+            self._log_console_output(servers)
+            raise