Add support for fetching console logs from servers

Added get_server_console method to fetch the console
log from a Server. On clouds that do not expose this
feature, a debug line will be logged and an empty
string will be returned.

Change-Id: Ifb973c7d382118d3a8b6bf406cb7ed463b057180

releasenotes/notes/add-server-console-078ed2696e5b04d9.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - Added get_server_console method to fetch the console
+    log from a Server. On clouds that do not expose this
+    feature, a debug line will be logged and an empty
+    string will be returned.

shade/_tasks.py

@@ -152,6 +152,11 @@ class ServerListSecurityGroups(task_manager.Task):
         return client.nova_client.servers.list_security_group(**self.args)
 
 
+class ServerConsoleGet(task_manager.Task):
+    def main(self, client):
+        return client.nova_client.servers.get_console_output(**self.args)
+
+
 class ServerGet(task_manager.Task):
     def main(self, client):
         return client.nova_client.servers.get(**self.args)

shade/openstackcloud.py

@@ -1969,6 +1969,40 @@ class OpenStackCloud(object):
         return _utils._get_entity(
             self.search_security_groups, name_or_id, filters)
 
+    def get_server_console(self, server, length=None):
+        """Get the console log for a server.
+
+        :param server: The server to fetch the console log for. Can be either
+                       a server dict or the Name or ID of the server.
+        :param int length: The number of lines you would like to retrieve from
+                           the end of the log. (optional, defaults to all)
+
+        :returns: A string containing the text of the console log or an
+                  empty string if the cloud does not support console logs.
+        :raises: OpenStackCloudException if an invalid server argument is given
+                 or if something else unforseen happens
+        """
+
+        if not isinstance(server, dict):
+            server = self.get_server(server)
+
+        if not server:
+            raise OpenStackCloudException(
+                "Console log requested for invalid server")
+
+        try:
+            return self.manager.submitTask(
+                _tasks.ServerConsoleGet(server=server['id'], length=length),
+                raw=True)
+        except nova_exceptions.BadRequest:
+            return ""
+        except OpenStackCloudException:
+            raise
+        except Exception as e:
+            raise OpenStackCloudException(
+                "Unable to get console log for {server}: {exception}".format(
+                    server=server['id'], exception=str(e)))
+
     def get_server(self, name_or_id=None, filters=None, detailed=False):
         """Get a server by name or ID.
 

shade/task_manager.py

@@ -92,7 +92,7 @@ class Task(object):
         elif (not isinstance(self._result, bool) and
               not isinstance(self._result, int) and
               not isinstance(self._result, float) and
-              not isinstance(self._result, str) and
+              not isinstance(self._result, six.string_types) and
               not isinstance(self._result, set) and
               not isinstance(self._result, tuple) and
               not isinstance(self._result, types.GeneratorType)):

shade/tests/functional/test_compute.py

@@ -19,9 +19,12 @@ test_compute
 Functional tests for `shade` compute methods.
 """
 
+import six
+
 from shade import exc
 from shade.tests.functional import base
 from shade.tests.functional.util import pick_flavor, pick_image
+from shade import _utils
 
 
 class TestCompute(base.BaseFunctionalTestCase):
@@ -67,6 +70,40 @@ class TestCompute(base.BaseFunctionalTestCase):
             self.demo_cloud.delete_server(self.server_name, wait=True))
         self.assertIsNone(self.demo_cloud.get_server(self.server_name))
 
+    def test_get_server_console(self):
+        self.addCleanup(self._cleanup_servers_and_volumes, self.server_name)
+        server = self.demo_cloud.create_server(
+            name=self.server_name,
+            image=self.image,
+            flavor=self.flavor,
+            wait=True)
+        for _ in _utils._iterate_timeout(
+                5, "Did not get more than 0 lines in the console log"):
+            log = self.demo_cloud.get_server_console(server=server)
+            self.assertTrue(isinstance(log, six.string_types))
+            if len(log) > 0:
+                break
+
+    def test_get_server_console_name_or_id(self):
+        self.addCleanup(self._cleanup_servers_and_volumes, self.server_name)
+        self.demo_cloud.create_server(
+            name=self.server_name,
+            image=self.image,
+            flavor=self.flavor,
+            wait=True)
+        for _ in _utils._iterate_timeout(
+                5, "Did not get more than 0 lines in the console log"):
+            log = self.demo_cloud.get_server_console(server=self.server_name)
+            self.assertTrue(isinstance(log, six.string_types))
+            if len(log) > 0:
+                break
+
+    def test_get_server_console_bad_server(self):
+        self.assertRaises(
+            exc.OpenStackCloudException,
+            self.demo_cloud.get_server_console,
+            server=self.server_name)
+
     def test_create_and_delete_server_with_admin_pass(self):
         self.addCleanup(self._cleanup_servers_and_volumes, self.server_name)
         server = self.demo_cloud.create_server(

shade/tests/unit/test_server_console.py

@@ -0,0 +1,61 @@
+# -*- coding: utf-8 -*-
+
+# 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.
+
+
+import mock
+import novaclient.exceptions as nova_exceptions
+
+import shade
+from shade.tests.unit import base
+from shade.tests import fakes
+
+
+class TestServerConsole(base.TestCase):
+
+    @mock.patch.object(shade.OpenStackCloud, 'nova_client')
+    def test_get_server_console_dict(self, mock_nova):
+        server = dict(id='12345')
+        self.cloud.get_server_console(server)
+
+        mock_nova.servers.list.assert_not_called()
+        mock_nova.servers.get_console_output.assert_called_once_with(
+            server='12345', length=None)
+
+    @mock.patch.object(shade.OpenStackCloud, 'has_service')
+    @mock.patch.object(shade.OpenStackCloud, 'nova_client')
+    def test_get_server_console_name_or_id(self, mock_nova, mock_has_service):
+        server = '12345'
+
+        fake_server = fakes.FakeServer(server, '', 'ACTIVE')
+        mock_nova.servers.get.return_value = fake_server
+        mock_nova.servers.list.return_value = [fake_server]
+        mock_has_service.return_value = False
+
+        self.cloud.get_server_console(server)
+
+        mock_nova.servers.get_console_output.assert_called_once_with(
+            server='12345', length=None)
+
+    @mock.patch.object(shade.OpenStackCloud, 'nova_client')
+    def test_get_server_console_no_console(self, mock_nova):
+        server = dict(id='12345')
+        exc = nova_exceptions.BadRequest(
+            'There is no such action: os-getConsoleOutput')
+        mock_nova.servers.get_console_output.side_effect = exc
+        log = self.cloud.get_server_console(server)
+
+        self.assertEqual('', log)
+        mock_nova.servers.list.assert_not_called()
+        mock_nova.servers.get_console_output.assert_called_once_with(
+            server='12345', length=None)