Initial implementation of refresh instance states

10 files changed, 194 insertions, 19 deletions

diff --git a/nova/compute/driver.py b/nova/compute/driver.py
new file mode 100644
index 000000000..bda82c60a
--- /dev/null
+++ b/nova/compute/driver.py
@@ -0,0 +1,38 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2011 Justin Santa Barbara
+# 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.
+
+"""
+Driver base-classes:
+
+    (Beginning of) the contract that compute drivers must follow, and shared
+    types that support that contract
+"""
+
+from nova.compute import power_state
+
+
+class InstanceInfo(object):
+    def __init__(self, name, state):
+        self.name = name
+        assert state in power_state.valid_states()
+        self.state = state
+
+
+class ComputeDriver(object):
+    def list_instances_detail(self):
+        """Return a list of InstanceInfo for all registered VMs"""
+        raise NotImplementedError()
diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index 0cab10fc3..057371d40 100644
--- a/nova/compute/manager.py
+++ b/nova/compute/manager.py
@@ -2,6 +2,7 @@
 
 # Copyright 2010 United States Government as represented by the
 # Administrator of the National Aeronautics and Space Administration.
+# Copyright 2011 Justin Santa Barbara
 # All Rights Reserved.
 #
 #    Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -51,6 +52,7 @@ from nova import manager
 from nova import rpc
 from nova import utils
 from nova.compute import power_state
+from nova.compute import driver
 
 FLAGS = flags.FLAGS
 flags.DEFINE_string('instances_path', '$state_path/instances',
@@ -115,7 +117,9 @@ class ComputeManager(manager.Manager):
         #             and redocument the module docstring
         if not compute_driver:
             compute_driver = FLAGS.compute_driver
-        self.driver = utils.import_object(compute_driver)
+        self.driver = utils.check_instance(utils.import_object(
+                                                            compute_driver),
+                                           driver.ComputeDriver)
         self.network_manager = utils.import_object(FLAGS.network_manager)
         self.volume_manager = utils.import_object(FLAGS.volume_manager)
         super(ComputeManager, self).__init__(*args, **kwargs)
@@ -974,3 +978,53 @@ class ComputeManager(manager.Manager):
 
         for volume in instance_ref['volumes']:
             self.db.volume_update(ctxt, volume['id'], {'status': 'in-use'})
+
+    def periodic_tasks(self, context=None):
+        """Tasks to be run at a periodic interval."""
+        super(ComputeManager, self).periodic_tasks(context)
+        try:
+            self._poll_instance_states(context)
+        except Exception as ex:
+            LOG.warning(_("Error during instance poll: %s"),
+                        unicode(ex))
+
+    def _poll_instance_states(self, context):
+        vm_instances = self.driver.list_instances_detail(context)
+        vm_instances = dict((vm.name, vm) for vm in vm_instances)
+
+        # Keep a list of VMs not in the DB, cross them off as we find them
+        vms_not_found_in_db = [vm.name for vm in vm_instances]
+
+        db_instances = self.db.instance_get_all_by_host(context, self.host)
+        for db_instance in db_instances:
+            name = db_instance['name']
+            vm_instance = vm_instances.get(name)
+            if vm_instance is None:
+                LOG.info(_("Found instance '%(name)' in DB but no VM. "
+                           "Shutting off.") % locals())
+                vm_state = power_state.SHUTOFF
+            else:
+                vm_state = vm_instance.state
+                vms_not_found_in_db.remove(name)
+
+            db_state = db_instance['state']
+            if vm_state != db_state:
+                LOG.info(_("DB/VM state mismatch. Changing state from "
+                           "%(db_state) to %(vm_state)") % locals())
+                self.db.instance_set_state(context,
+                                           db_instance['id'],
+                                           vm_state)
+
+            if vm_state == power_state.SHUTOFF:
+                # TODO(soren): This is what the compute manager does when you
+                # terminate an instance. At some point I figure we'll have a
+                # "terminated" state and some sort of cleanup job that runs
+                # occasionally, cleaning them out.
+                self.db.instance_destroy(context, db_instance['id'])
+
+        # Are there VMs not in the DB?
+        for vm_not_found_in_db in vms_not_found_in_db:
+            name = vm_not_found_in_db
+            #TODO(justinsb): What to do here?  Adopt it?  Shut it down?
+            LOG.warning(_("Found VM not in DB: %(name).  Ignoring")
+                        % locals())
diff --git a/nova/compute/power_state.py b/nova/compute/power_state.py
index adfc2dff0..145362f97 100644
--- a/nova/compute/power_state.py
+++ b/nova/compute/power_state.py
@@ -2,6 +2,7 @@
 
 # Copyright 2010 United States Government as represented by the
 # Administrator of the National Aeronautics and Space Administration.
+# Copyright 2011 Justin Santa Barbara
 # All Rights Reserved.
 # Copyright (c) 2010 Citrix Systems, Inc.
 #
@@ -19,6 +20,7 @@
 
 """The various power states that a VM can be in."""
 
+#NOTE(justinsb): These are the virDomainState values from libvirt
 NOSTATE = 0x00
 RUNNING = 0x01
 BLOCKED = 0x02
@@ -29,9 +31,8 @@ CRASHED = 0x06
 SUSPENDED = 0x07
 FAILED = 0x08
 
-
-def name(code):
-    d = {
+#TODO(justinsb): Power state really needs to be a proper class...
+_STATE_MAP = {
         NOSTATE: 'pending',
         RUNNING: 'running',
         BLOCKED: 'blocked',
@@ -41,4 +42,11 @@ def name(code):
         CRASHED: 'crashed',
         SUSPENDED: 'suspended',
         FAILED: 'failed to spawn'}
-    return d[code]
+
+
+def name(code):
+    return _STATE_MAP[code]
+
+
+def valid_states():
+    return _STATE_MAP.values()
diff --git a/nova/utils.py b/nova/utils.py
index 87e726394..e93f489be 100644
--- a/nova/utils.py
+++ b/nova/utils.py
@@ -585,3 +585,12 @@ def get_from_path(items, path):
         return results
     else:
         return get_from_path(results, remainder)
+
+
+def check_instance(obj, cls):
+    """Checks that obj is of type cls, and lets PyLint infer types"""
+    if isinstance(obj, cls):
+        return obj
+    raise Exception(_("Expected object of type: %s") % (str(cls)))
+    #TODO(justinsb): Can we make this better??
+    return cls()  # Ugly PyLint hack
diff --git a/nova/virt/connection.py b/nova/virt/connection.py
index 13181b730..d585b6c21 100644
--- a/nova/virt/connection.py
+++ b/nova/virt/connection.py
@@ -23,6 +23,8 @@ import sys
 
 from nova import flags
 from nova import log as logging
+from nova import utils
+from nova.compute import driver
 from nova.virt import fake
 from nova.virt import libvirt_conn
 from nova.virt import xenapi_conn
@@ -72,4 +74,4 @@ def get_connection(read_only=False):
     if conn is None:
         LOG.error(_('Failed to open connection to the hypervisor'))
         sys.exit(1)
-    return conn
+    return utils.check_instance(conn, driver.ComputeDriver)
diff --git a/nova/virt/fake.py b/nova/virt/fake.py
index 3a06284a1..18cca3f5e 100644
--- a/nova/virt/fake.py
+++ b/nova/virt/fake.py
@@ -26,6 +26,8 @@ semantics of real hypervisor connections.
 """
 
 from nova import exception
+from nova import utils
+from nova.compute import driver
 from nova.compute import power_state
 
 
@@ -34,7 +36,14 @@ def get_connection(_):
     return FakeConnection.instance()
 
 
-class FakeConnection(object):
+class FakeInstance(object):
+
+    def __init__(self, name, state):
+        self.name = name
+        self.state = state
+
+
+class FakeConnection(driver.ComputeDriver):
     """
     The interface to this class talks in terms of 'instances' (Amazon EC2 and
     internal Nova terminology), by which we mean 'running virtual machine'
@@ -90,6 +99,17 @@ class FakeConnection(object):
         """
         return self.instances.keys()
 
+    def _map_to_instance_info(self, instance):
+        instance = utils.check_instance(instance, FakeInstance)
+        info = driver.InstanceInfo(instance.name, instance.state)
+        return info
+
+    def list_instances_detail(self):
+        info_list = []
+        for instance in self.instances:
+            info_list.append(self._map_to_instance_info(instance))
+        return info_list
+
     def spawn(self, instance):
         """
         Create a new instance/VM/domain on the virtualization platform.
@@ -109,9 +129,10 @@ class FakeConnection(object):
         that it was before this call began.
         """
 
-        fake_instance = FakeInstance()
-        self.instances[instance.name] = fake_instance
-        fake_instance._state = power_state.RUNNING
+        name = instance.name
+        state = power_state.RUNNING
+        fake_instance = FakeInstance(name, state)
+        self.instances[name] = fake_instance
 
     def snapshot(self, instance, name):
         """
@@ -270,7 +291,7 @@ class FakeConnection(object):
             raise exception.NotFound(_("Instance %s Not Found")
                                      % instance_name)
         i = self.instances[instance_name]
-        return {'state': i._state,
+        return {'state': i.state,
                 'max_mem': 0,
                 'mem': 0,
                 'num_cpu': 2,
@@ -428,8 +449,3 @@ class FakeConnection(object):
         """This method is supported only by libvirt."""
         raise NotImplementedError('This method is supported only by libvirt.')
 
-
-class FakeInstance(object):
-
-    def __init__(self):
-        self._state = power_state.NOSTATE
diff --git a/nova/virt/hyperv.py b/nova/virt/hyperv.py
index 29d18dac5..aea7413c6 100644
--- a/nova/virt/hyperv.py
+++ b/nova/virt/hyperv.py
@@ -67,6 +67,7 @@ from nova import exception
 from nova import flags
 from nova import log as logging
 from nova.auth import manager
+from nova.compute import driver
 from nova.compute import power_state
 from nova.virt import images
 
@@ -108,8 +109,9 @@ def get_connection(_):
     return HyperVConnection()
 
 
-class HyperVConnection(object):
+class HyperVConnection(driver.ComputeDriver):
     def __init__(self):
+        super(HyperVConnection, self).__init__()
         self._conn = wmi.WMI(moniker='//./root/virtualization')
         self._cim_conn = wmi.WMI(moniker='//./root/cimv2')
 
diff --git a/nova/virt/libvirt_conn.py b/nova/virt/libvirt_conn.py
index 0b306c950..e95bcac39 100644
--- a/nova/virt/libvirt_conn.py
+++ b/nova/virt/libvirt_conn.py
@@ -60,6 +60,7 @@ from nova import log as logging
 #from nova import test
 from nova import utils
 from nova.auth import manager
+from nova.compute import driver
 from nova.compute import instance_types
 from nova.compute import power_state
 from nova.virt import disk
@@ -154,9 +155,10 @@ def _get_ip_version(cidr):
         return int(net.version())
 
 
-class LibvirtConnection(object):
+class LibvirtConnection(driver.ComputeDriver):
 
     def __init__(self, read_only):
+        super(LibvirtConnection, self).__init__()
         self.libvirt_uri = self.get_uri()
 
         self.libvirt_xml = open(FLAGS.libvirt_xml_template).read()
@@ -235,6 +237,26 @@ class LibvirtConnection(object):
         return [self._conn.lookupByID(x).name()
                 for x in self._conn.listDomainsID()]
 
+    def _map_to_instance_info(self, domain):
+        # .info() returns a list of:
+        #state: one of the state values (virDomainState)
+        #maxMemory: the maximum memory used by the domain
+        #memory: the current amount of memory used by the domain
+        #nbVirtCPU: the number of virtual CPU
+        #cpuTime: the time used by the domain in nanoseconds
+        (state, _max_mem, _mem, _num_cpu, _cpu_time) = domain.info()
+        name = domain.name()
+
+        return driver.InstanceInfo(name, state)
+
+    def list_instances_detail(self):
+        infos = []
+        for domain_id in self._conn.listDomainsID():
+            domain = self._conn.lookupById(domain_id)
+            info = self._map_to_instance_info(domain)
+            infos.append(info)
+        return infos
+
     def destroy(self, instance, cleanup=True):
         try:
             virt_dom = self._conn.lookupByName(instance['name'])
diff --git a/nova/virt/xenapi/vmops.py b/nova/virt/xenapi/vmops.py
index fcb290d03..2fce93e38 100644
--- a/nova/virt/xenapi/vmops.py
+++ b/nova/virt/xenapi/vmops.py
@@ -34,6 +34,7 @@ from nova import exception
 from nova import utils
 
 from nova.auth.manager import AuthManager
+from nova.compute import driver
 from nova.compute import power_state
 from nova.virt.xenapi.network_utils import NetworkHelper
 from nova.virt.xenapi.vm_utils import VMHelper
@@ -55,6 +56,8 @@ class VMOps(object):
 
     def list_instances(self):
         """List VM instances"""
+        # TODO(justinsb): Should we just always use the details method?
+        #  Seems to be the same number of API calls..
         vm_refs = []
         for vm_ref in self._session.get_xenapi().VM.get_all():
             vm_rec = self._session.get_xenapi().VM.get_record(vm_ref)
@@ -62,6 +65,22 @@ class VMOps(object):
                 vm_refs.append(vm_rec["name_label"])
         return vm_refs
 
+    def list_instances_detail(self):
+        """List VM instances, returning InstanceInfo objects"""
+        instance_infos = []
+        for vm_ref in self._session.get_xenapi().VM.get_all():
+            vm_rec = self._session.get_xenapi().VM.get_record(vm_ref)
+            if not vm_rec["is_a_template"] and not vm_rec["is_control_domain"]:
+                name = vm_rec["name_label"]
+                
+                #TODO(justinsb): Yuk...
+                openstack_format = VMHelper.compile_info(vm_rec)
+                state = openstack_format['state']
+
+                instance_info = driver.InstanceInfo(name, state)
+                instance_infos.append(instance_info)
+        return instance_infos
+
     def _start(self, instance, vm_ref=None):
         """Power on a VM instance"""
         if not vm_ref:
diff --git a/nova/virt/xenapi_conn.py b/nova/virt/xenapi_conn.py
index da42a83b6..9390db0bb 100644
--- a/nova/virt/xenapi_conn.py
+++ b/nova/virt/xenapi_conn.py
@@ -69,6 +69,7 @@ from nova import db
 from nova import utils
 from nova import flags
 from nova import log as logging
+from nova.compute import driver
 from nova.virt.xenapi.vmops import VMOps
 from nova.virt.xenapi.volumeops import VolumeOps
 
@@ -141,10 +142,11 @@ def get_connection(_):
     return XenAPIConnection(url, username, password)
 
 
-class XenAPIConnection(object):
+class XenAPIConnection(driver.ComputeDriver):
     """A connection to XenServer or Xen Cloud Platform"""
 
     def __init__(self, url, user, pw):
+        super(XenAPIConnection, self).__init__()
         session = XenAPISession(url, user, pw)
         self._vmops = VMOps(session)
         self._volumeops = VolumeOps(session)
@@ -160,6 +162,9 @@ class XenAPIConnection(object):
         """List VM instances"""
         return self._vmops.list_instances()
 
+    def list_instances_detail(self):
+        return self._vmops.list_instances_detail()
+
     def spawn(self, instance):
         """Create VM instance"""
         self._vmops.spawn(instance)