[Kimchi-devel] [v6 1/1] Virtual machine migration

simonjin at linux.vnet.ibm.com simonjin at linux.vnet.ibm.com
Tue Dec 16 02:39:24 UTC 2014


From: Simon Jin <simonjin at linux.vnet.ibm.com>

v6-v5:Fix pep8, delete migratation finish func.
Signed-off-by: Simon Jin <simonjin at linux.vnet.ibm.com>
---
 docs/API.md               |   5 ++
 src/kimchi/control/vms.py |   3 +
 src/kimchi/i18n.py        |   8 +++
 src/kimchi/model/vms.py   | 166 +++++++++++++++++++++++++++++++++++++++++++++-
 4 files changed, 180 insertions(+), 2 deletions(-)

diff --git a/docs/API.md b/docs/API.md
index 210a036..4408764 100644
--- a/docs/API.md
+++ b/docs/API.md
@@ -132,6 +132,11 @@ the following general conventions:
          It emulates the power reset button on a machine. Note that there is a
          risk of data loss caused by reset without the guest OS shutdown.
 * connect: Prepare the connection for spice or vnc
+* migrate: Migrate a virtual machine to a remote server, only support live mode without block migration.
+    * remoteHost: IP address or hostname of the remote server.
+    * user: User of the remote server.
+    * passwd: Passwd of user on remote server.
+    * secure: Migrate in P2P secure tunel mode.(optional)
 
 * clone: Create a new VM identical to this VM. The new VM's name, UUID and
          network MAC addresses will be generated automatically. Each existing
diff --git a/src/kimchi/control/vms.py b/src/kimchi/control/vms.py
index a1589ef..3638b3a 100644
--- a/src/kimchi/control/vms.py
+++ b/src/kimchi/control/vms.py
@@ -42,6 +42,9 @@ class VM(Resource):
         for ident, node in sub_nodes.items():
             setattr(self, ident, node(model, self.ident))
         self.start = self.generate_action_handler('start')
+        self.migrate = self.generate_action_handler_task('migrate',
+                                                         ['remoteHost', 'user',
+                                                          'passwd', 'secure'])
         self.poweroff = self.generate_action_handler('poweroff')
         self.shutdown = self.generate_action_handler('shutdown')
         self.reset = self.generate_action_handler('reset')
diff --git a/src/kimchi/i18n.py b/src/kimchi/i18n.py
index e3a051c..81a6dbb 100644
--- a/src/kimchi/i18n.py
+++ b/src/kimchi/i18n.py
@@ -107,6 +107,14 @@ messages = {
     "KCHVM0033E": _("Virtual machine '%(name)s' must be stopped before cloning it."),
     "KCHVM0034E": _("Insufficient disk space to clone virtual machine '%(name)s'"),
     "KCHVM0035E": _("Unable to clone VM '%(name)s'. Details: %(err)s"),
+    "KCHVM0036E": _("Migrate %(name)s to localhost %(remoteHost)s is not allowed."),
+    "KCHVM0037E": _("vm %(name)s is already in migrating, can not perform migrate on it again."),
+    "KCHVM0038E": _("Can't migrate vm %(name)s on Hypervisor arch %(srcarch)s.to a different Hypervisor arch %(destarch)s."),
+    "KCHVM0039E": _("Can't migrate %(name)s from %(srchyp)s to a different Hypervisor type %(desthyp)s."),
+    "KCHVM0040E": _("Can't migrate vm %(name)s, vm has passthrough device %(hostdevs)s."),
+    "KCHVM0041E": _("Can not migrate vm %(name)s when its in %(state)s state."),
+    "KCHVM0042E": _("Failed Migrate vm %(name)s due error: %(err)s"),
+    "KCHVM0043E": _("Failed to destroy vm %(name)s from migration recover. Details: %(err)s"),
 
     "KCHVMHDEV0001E": _("VM %(vmid)s does not contain directly assigned host device %(dev_name)s."),
     "KCHVMHDEV0002E": _("The host device %(dev_name)s is not allowed to directly assign to VM."),
diff --git a/src/kimchi/model/vms.py b/src/kimchi/model/vms.py
index 3aa1145..023bd10 100644
--- a/src/kimchi/model/vms.py
+++ b/src/kimchi/model/vms.py
@@ -33,9 +33,10 @@ from cherrypy.process.plugins import BackgroundTask
 from kimchi import model, vnc
 from kimchi.config import READONLY_POOL_TYPE, config
 from kimchi.exception import InvalidOperation, InvalidParameter
-from kimchi.exception import NotFoundError, OperationFailed
+from kimchi.exception import NotFoundError, OperationFailed, KimchiException
 from kimchi.model.config import CapabilitiesModel
-from kimchi.model.tasks import TaskModel
+from kimchi.model.libvirtconnection import LibvirtConnection
+from kimchi.model.tasks import TaskModel, TasksModel
 from kimchi.model.templates import TemplateModel
 from kimchi.model.utils import get_vm_name
 from kimchi.model.utils import get_metadata_node
@@ -268,6 +269,7 @@ class VMModel(object):
         self.groups = import_class('kimchi.model.groups.GroupsModel')(**kargs)
         self.vms = VMsModel(**kargs)
         self.task = TaskModel(**kargs)
+        self.tasks = TasksModel(**kargs)
         self.storagepool = model.storagepools.StoragePoolModel(**kargs)
         self.storagevolume = model.storagevolumes.StorageVolumeModel(**kargs)
         self.storagevolumes = model.storagevolumes.StorageVolumesModel(**kargs)
@@ -850,6 +852,166 @@ class VMModel(object):
             raise OperationFailed("KCHVM0019E",
                                   {'name': name, 'err': e.get_error_message()})
 
+    def _preCheck(self, name, destConn, remoteHost):
+        """Pre check before migration"""
+
+        kimchi_log.debug('precheck migrate %s' % name)
+        _destConn = destConn.get()
+        if remoteHost in ['localhost', '127.0.0.1']:
+            kimchi_log.debug('vm %s Can not migrate to localhost.' % name)
+            raise OperationFailed("KCHVM0036E", {'name': name,
+                                                 'remoteHost': remoteHost})
+        # check if the vm already in migration
+        try:
+            alltasks = self.tasks.get_list()
+            for taskid in alltasks:
+                taskobj = self.task.lookup(taskid)
+                if taskobj['target_uri'] == "/vms/%s/migrate" % name \
+                        and taskobj['status'] == "running":
+                    kimchi_log.debug('vm %s is already in migrating.' % name)
+                    raise OperationFailed("KCHVM0037E", {'name': name})
+        except NotFoundError:
+            kimchi_log.debug('No previous migrate on vm %s.' % name)
+
+        srcarch = self.conn.get().getInfo()[0]
+        destarch = _destConn.getInfo()[0]
+        if srcarch != destarch:
+            kimchi_log.debug('vm %s can not migrate to different arch server.'
+                             % (name, destarch))
+            raise OperationFailed("KCHVM0038E", {'name': name,
+                                                 'srcarch': srcarch,
+                                                 'destarch': destarch})
+        srchyp = self.conn.get().getType()
+        desthyp = _destConn.getType()
+        if srchyp != desthyp:
+            kimchi_log.debug('vm %s can not migrate to a different hypervisor'
+                             % name)
+            raise OperationFailed("KCHVM0039E", {'name': name,
+                                                 'srchyp': srchyp,
+                                                 'desthyp': desthyp})
+
+        # model.host import DOM_STATE_MAP, vmhostdevs import host,
+        # to void loop import DOM_STATE_MAP, move import VMHostDevsModel here
+        from kimchi.model.vmhostdevs import VMHostDevsModel
+        # check if there is any passthrough devices belong to this vm
+        vmhostdevs = VMHostDevsModel(conn=self.conn)
+        hostdevs = vmhostdevs.get_list(name)
+        if hostdevs:
+            raise OperationFailed("KCHVM0040E", {'name': name,
+                                  'hostdevs': hostdevs})
+
+    @staticmethod
+    def _getRemoteConn(remoteHost, user, passwd, transport='ssh'):
+        """open destination connect to migrate"""
+
+        duri = 'qemu+%s://%s@%s/system' % (transport, user, remoteHost)
+        conn = LibvirtConnection(duri)
+        return conn
+
+    def _do_migrate(self, cb, params):
+        """Asynchronous function which performs the migrate operation.
+
+        Arguments:
+        cb -- A callback function to signal the Task's progress.
+        params -- A dict with the following values:
+           "name": Name of the virtual machine to be migrated.
+           "destConn": A LibvirtConnection to destination server.
+           "remoteHost": The migration destination server.
+           "secure": Migrate in P2P secure tunel mode.(optional)
+        """
+
+        name = params['name'].decode('utf-8')
+        destConn = params['destConn']
+        remoteHost = params['remoteHost']
+        secure = params['secure']
+        _destConn = destConn.get()
+
+        cb('starting a migration')
+        kimchi_log.debug('migrate %s start' % name)
+        dom = self.get_vm(name, self.conn)
+        flag = 0
+        if secure:
+            flag |= (libvirt.VIR_MIGRATE_PEER2PEER |
+                     libvirt.VIR_MIGRATE_TUNNELLED)
+
+        state = DOM_STATE_MAP[dom.info()[0]]
+        if state in ['running', 'paused']:
+            flag |= libvirt.VIR_MIGRATE_LIVE
+        elif state == 'shutoff':
+            flag |= (libvirt.VIR_MIGRATE_OFFLINE |
+                     libvirt.VIR_MIGRATE_PERSIST_DEST)
+        else:
+            kimchi_log.debug('Can not migrate vm %s when its in %s.'
+                             % (name, state))
+            raise OperationFailed("KCHVM0041E", {'name': name,
+                                                 'state': state})
+        try:
+            dom.migrate(_destConn, flag, None, None, 0)
+        except libvirt.libvirtError as e:
+            kimchi_log.error('migrate %s to %s failed' % (name, remoteHost))
+            self._recover(name, destConn, cb)
+            kimchi_log.debug('finish migrate %s' % name)
+            cb('Migrate finished', False)
+            raise OperationFailed('KCHVM0042E', {'err': e.message,
+                                                 'name': name})
+        kimchi_log.debug('finish migrate %s' % name)
+        cb('Migrate finished', True)
+
+    def migrate(self, name, remoteHost, user, passwd=None, secure=False):
+        """Migrate a virtual machine to a remote server.
+
+        Arguments:
+        name -- The name of the virtual machine to be migrated.
+        remoteHost -- Remote server that the VM will be migrated to.
+        user -- Login user on remote server,prefer root.
+        passwd -- The password of the user on remote server,
+        if the local server
+        has ssk key exchanged, then this param can be NULL.
+        secure -- Migrate in P2P secure tunel mode.(optional)
+
+        Return:
+        A Task running the clone operation.
+        """
+        name = name.decode('utf-8')
+        remoteHost = remoteHost.decode('utf-8')
+        user = user.decode('utf-8')
+
+        destConn = self._getRemoteConn(remoteHost, user, passwd)
+        self._preCheck(name, destConn, remoteHost)
+
+        params = {'name': name,
+                  'destConn': destConn,
+                  'remoteHost': remoteHost,
+                  'secure': secure}
+        task_id = add_task('/vms/%s/migrate' % name, self._do_migrate,
+                           self.objstore, params)
+
+        return self.task.lookup(task_id)
+
+    def _recover(self, name, destconn, cb):
+        """Recover from a failed migration.
+
+        Arguments:
+        "cb": A callback function to signal the Task's progress.
+        "name": Name of the virtual machine to be migrated.
+        "destConn": A LibvirtConnection to destination server.
+        """
+        try:
+            destvm = self.get_vm(name, destconn)
+        except KimchiException as e:
+            if type(e) == NotFoundError:
+                return
+
+        cb('recover from a failed migration', False)
+        kimchi_log.debug('recover from a failed migrate %s' % name)
+        try:
+            destvm.destroy()
+            kimchi_log.error("Failed to destory migrate vm %s on \
+                              destination server" % name)
+        except libvirt.libvirtError as e:
+            raise OperationFailed('KCHVM0043E', {'name': name,
+                                                 'err': e.message})
+
     def poweroff(self, name):
         dom = self.get_vm(name, self.conn)
         try:
-- 
1.8.3.1




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