VMware: serial console log (completed)

Commit ace11d3 adds a serial port device to instances, so the serial
console output can be sent to a virtual serial port concentrator (VSPC).
This patch finishes the implementation by returning the output saved by
VSPC to the end user. The config option 'serial_log_dir' should have the
same value as in the VSPC configuration (i.e. it must point to the same
directory).

The VSPC implementation is available at
https://github.com/openstack/vmware-vspc

blueprint vmware-console-log-complete

Change-Id: I7e40dc41b0354d414bc8eae331f8257959e1d123

doc/source/user/support-matrix.ini

@@ -955,7 +955,7 @@ driver-impl-libvirt-kvm-s390x=complete
 driver-impl-libvirt-qemu-x86=complete
 driver-impl-libvirt-lxc=missing
 driver-impl-libvirt-xen=complete
-driver-impl-vmware=missing
+driver-impl-vmware=complete
 driver-impl-hyperv=complete
 driver-impl-ironic=missing
 driver-impl-libvirt-vz-vm=missing

nova/conf/vmware.py

@@ -91,6 +91,13 @@ Possible values:
 Related options:
 This option is ignored if serial_port_service_uri is not specified.
 * serial_port_service_uri
+"""),
+    cfg.StrOpt('serial_log_dir',
+               default='/opt/vmware/vspc',
+               help="""
+Specifies the directory where the Virtual Serial Port Concentrator is
+storing console log files. It should match the 'serial_log_dir' config
+value of VSPC.
 """),
 ]
 

nova/tests/unit/virt/vmwareapi/test_driver_api.py

@@ -1671,10 +1671,6 @@ class VMwareAPIVMTestCase(test.NoDBTestCase,
         actual = self.conn.get_instance_diagnostics(instance)
         self.assertDiagnosticsEqual(expected, actual)
 
-    def test_get_console_output(self):
-        self.assertRaises(NotImplementedError, self.conn.get_console_output,
-            None, None)
-
     def test_get_vnc_console_non_existent(self):
         self._create_instance()
         self.assertRaises(exception.InstanceNotFound,
@@ -1702,6 +1698,24 @@ class VMwareAPIVMTestCase(test.NoDBTestCase,
                           self.context,
                           self.instance)
 
+    def test_get_console_output(self):
+        self.flags(serial_log_dir='/opt/vspc', group='vmware')
+        self._create_instance()
+        with test.nested(
+            mock.patch('os.path.exists', return_value=True),
+            mock.patch('{}.open'.format(driver.__name__), create=True),
+            mock.patch('nova.privsep.path.last_bytes')
+        ) as (fake_exists, fake_open, fake_last_bytes):
+            fake_open.return_value = mock.MagicMock()
+            fake_fd = fake_open.return_value.__enter__.return_value
+            fake_last_bytes.return_value = b'fira', 0
+            output = self.conn.get_console_output(self.context, self.instance)
+            fname = self.instance.uuid.replace('-', '')
+            fake_exists.assert_called_once_with('/opt/vspc/{}'.format(fname))
+            fake_last_bytes.assert_called_once_with(fake_fd,
+                                                    driver.MAX_CONSOLE_BYTES)
+        self.assertEqual(b'fira', output)
+
     def test_get_volume_connector(self):
         self._create_vm()
         connector_dict = self.conn.get_volume_connector(self.instance)

nova/virt/vmwareapi/driver.py

@@ -19,10 +19,12 @@
 A connection to the VMware vCenter platform.
 """
 
+import os
 import re
 
 from oslo_log import log as logging
 from oslo_utils import excutils
+from oslo_utils import units
 from oslo_utils import versionutils as v_utils
 from oslo_vmware import api
 from oslo_vmware import exceptions as vexc
@@ -35,6 +37,7 @@ from nova.compute import task_states
 import nova.conf
 from nova import exception
 from nova.i18n import _
+import nova.privsep.path
 from nova.virt import driver
 from nova.virt.vmwareapi import constants
 from nova.virt.vmwareapi import error_util
@@ -49,6 +52,7 @@ LOG = logging.getLogger(__name__)
 CONF = nova.conf.CONF
 
 TIME_BETWEEN_API_CALL_RETRIES = 1.0
+MAX_CONSOLE_BYTES = 100 * units.Ki
 
 
 class VMwareVCDriver(driver.ComputeDriver):
@@ -259,6 +263,21 @@ class VMwareVCDriver(driver.ComputeDriver):
     def get_mks_console(self, context, instance):
         return self._vmops.get_mks_console(instance)
 
+    def get_console_output(self, context, instance):
+        if not CONF.vmware.serial_log_dir:
+            LOG.error("The 'serial_log_dir' config option is not set!")
+            return
+        fname = instance.uuid.replace('-', '')
+        path = os.path.join(CONF.vmware.serial_log_dir, fname)
+        if not os.path.exists(path):
+            LOG.warning('The console log is missing. Check your VSPC '
+                        'configuration', instance=instance)
+            return b""
+        with open(path, 'rb') as fp:
+            read_log_data, remaining = nova.privsep.path.last_bytes(
+                fp, MAX_CONSOLE_BYTES)
+            return read_log_data
+
     def _get_vcenter_uuid(self):
         """Retrieves the vCenter UUID."""
 

releasenotes/notes/vmware-console-log-384fbb9a6aa095ad.yaml

@@ -0,0 +1,8 @@
+---
+features:
+  - |
+    VMware serial console log is completed. `VSPC`_ must be deployed along
+    with nova-compute and configured properly. The ``[vmware]/serial_log_dir``
+    config option must have the same value in both nova.conf and vspc.conf.
+
+    .. _VSPC: https://github.com/openstack/vmware-vspc