pvc/node-daemon/pvcnoded/objects/VMInstance.py

961 lines
34 KiB
Python

#!/usr/bin/env python3
# VMInstance.py - Class implementing a PVC virtual machine in pvcnoded
# Part of the Parallel Virtual Cluster (PVC) system
#
# Copyright (C) 2018-2022 Joshua M. Boniface <joshua@boniface.me>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, version 3.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
#
###############################################################################
import uuid
import time
import libvirt
from threading import Thread
from xml.etree import ElementTree
import daemon_lib.common as common
import pvcnoded.objects.VMConsoleWatcherInstance as VMConsoleWatcherInstance
class VMInstance(object):
# Initialization function
def __init__(self, domuuid, zkhandler, config, logger, this_node):
# Passed-in variables on creation
self.domuuid = domuuid
self.zkhandler = zkhandler
self.config = config
self.logger = logger
self.this_node = this_node
# Get data from zookeeper
self.domname = self.zkhandler.read(("domain", domuuid))
self.state = self.zkhandler.read(("domain.state", domuuid))
self.node = self.zkhandler.read(("domain.node", domuuid))
self.lastnode = self.zkhandler.read(("domain.last_node", domuuid))
self.last_currentnode = self.zkhandler.read(("domain.node", domuuid))
self.last_lastnode = self.zkhandler.read(("domain.last_node", domuuid))
try:
self.migration_method = self.zkhandler.read(
("domain.meta.migrate_method", self.domuuid)
)
except Exception:
self.migration_method = "none"
# These will all be set later
self.instart = False
self.inrestart = False
self.inmigrate = False
self.inreceive = False
self.inshutdown = False
self.instop = False
# State thread
self.state_thread = None
# Libvirt domuuid
self.dom = self.lookupByUUID(self.domuuid)
# Log watcher instance
self.console_log_instance = VMConsoleWatcherInstance.VMConsoleWatcherInstance(
self.domuuid,
self.domname,
self.zkhandler,
self.config,
self.logger,
self.this_node,
)
# Watch for changes to the state field in Zookeeper
@self.zkhandler.zk_conn.DataWatch(
self.zkhandler.schema.path("domain.state", self.domuuid)
)
def watch_state(data, stat, event=""):
if event and event.type == "DELETED":
# The key has been deleted after existing before; terminate this watcher
# because this class instance is about to be reaped in Daemon.py
return False
# Perform a management command
self.logger.out("Updating state of VM {}".format(self.domuuid), state="i")
self.state_thread = Thread(target=self.manage_vm_state, args=(), kwargs={})
self.state_thread.start()
# Get data functions
def getstate(self):
return self.state
def getnode(self):
return self.node
def getlastnode(self):
return self.lastnode
def getdom(self):
return self.dom
def getmemory(self):
try:
if self.dom is not None:
memory = int(self.dom.info()[2] / 1024)
else:
domain_information = common.getInformationFromXML(
self.zkhandler, self.domuuid
)
memory = int(domain_information["memory"])
except Exception:
memory = 0
return memory
def getvcpus(self):
try:
vcpus = int(self.dom.info()[3])
except Exception:
vcpus = 0
return vcpus
# Manage local node domain_list
def addDomainToList(self):
if self.domuuid not in self.this_node.domain_list:
try:
# Add the domain to the domain_list array
self.this_node.domain_list.append(self.domuuid)
# Push the change up to Zookeeper
self.zkhandler.write(
[
(
("node.running_domains", self.this_node.name),
" ".join(self.this_node.domain_list),
)
]
)
except Exception as e:
self.logger.out("Error adding domain to list: {}".format(e), state="e")
def removeDomainFromList(self):
if self.domuuid in self.this_node.domain_list:
try:
# Remove the domain from the domain_list array
self.this_node.domain_list.remove(self.domuuid)
# Push the change up to Zookeeper
self.zkhandler.write(
[
(
("node.running_domains", self.this_node.name),
" ".join(self.this_node.domain_list),
)
]
)
except Exception as e:
self.logger.out(
"Error removing domain from list: {}".format(e), state="e"
)
# Update the VNC live data
def update_vnc(self):
if self.dom is not None:
live_xml = ElementTree.fromstring(self.dom.XMLDesc(0))
graphics = live_xml.find("./devices/graphics")
if graphics is not None:
self.logger.out(
"Updating VNC data",
state="i",
prefix="Domain {}".format(self.domuuid),
)
port = graphics.get("port", "")
listen = graphics.get("listen", "")
self.zkhandler.write(
[
(
("domain.console.vnc", self.domuuid),
"{}:{}".format(listen, port),
)
]
)
else:
self.zkhandler.write([(("domain.console.vnc", self.domuuid), "")])
else:
self.zkhandler.write([(("domain.console.vnc", self.domuuid), "")])
# Attach a device to the running domain
def attach_device(self, xml_spec):
if not self.dom:
self.logger.out(
"Cannot attach device to non-running domain",
state="w",
prefix="Domain {}".format(self.domuuid),
)
return False
try:
self.logger.out(
"Attaching new device to VM",
state="i",
prefix="Domain {}".format(self.domuuid),
)
self.dom.attachDevice(xml_spec)
return True
except Exception as e:
self.logger.out(
"Failed to attach device: {}".format(e),
state="e",
prefix="Domain {}".format(self.domuuid),
)
return False
# Detach a device from the running domain
def detach_device(self, xml_spec):
if not self.dom:
self.logger.out(
"Cannot detach device from non-running domain",
state="w",
prefix="Domain {}".format(self.domuuid),
)
return False
try:
self.logger.out(
"Detaching device from VM",
state="i",
prefix="Domain {}".format(self.domuuid),
)
self.dom.detachDevice(xml_spec)
return True
except Exception as e:
self.logger.out(
"Failed to detach device: {}".format(e),
state="e",
prefix="Domain {}".format(self.domuuid),
)
return False
# Start up the VM
def start_vm(self):
# Start the log watcher
self.console_log_instance.start()
self.logger.out(
"Starting VM", state="i", prefix="Domain {}".format(self.domuuid)
)
self.instart = True
# Start up a new Libvirt connection
libvirt_name = "qemu:///system"
lv_conn = libvirt.open(libvirt_name)
if lv_conn is None:
self.logger.out(
"Failed to open local libvirt connection",
state="e",
prefix="Domain {}".format(self.domuuid),
)
self.instart = False
return
# Try to get the current state in case it's already running
try:
self.dom = self.lookupByUUID(self.domuuid)
curstate = self.dom.state()[0]
except Exception:
curstate = "notstart"
# Handle situations where the VM crashed or the node unexpectedly rebooted
if (
self.getdom() is None
or self.getdom().state()[0] != libvirt.VIR_DOMAIN_RUNNING
):
# Flush locks
self.logger.out(
"Flushing RBD locks", state="i", prefix="Domain {}".format(self.domuuid)
)
VMInstance.flush_locks(
self.zkhandler, self.logger, self.domuuid, self.this_node
)
if self.zkhandler.read(("domain.state", self.domuuid)) == "fail":
lv_conn.close()
self.dom = None
self.instart = False
return
if curstate == libvirt.VIR_DOMAIN_RUNNING:
# If it is running just update the model
self.addDomainToList()
self.zkhandler.write([(("domain.failed_reason", self.domuuid), "")])
else:
# Or try to create it
try:
# Grab the domain information from Zookeeper
xmlconfig = self.zkhandler.read(("domain.xml", self.domuuid))
dom = lv_conn.createXML(xmlconfig, 0)
self.addDomainToList()
self.logger.out(
"Successfully started VM",
state="o",
prefix="Domain {}".format(self.domuuid),
)
self.dom = dom
self.zkhandler.write([(("domain.failed_reason", self.domuuid), "")])
except libvirt.libvirtError as e:
self.logger.out(
"Failed to create VM",
state="e",
prefix="Domain {}".format(self.domuuid),
)
self.zkhandler.write(
[
(("domain.state", self.domuuid), "fail"),
(("domain.failed_reason", self.domuuid), str(e)),
]
)
lv_conn.close()
self.dom = None
self.instart = False
return
lv_conn.close()
self.instart = False
# Restart the VM
def restart_vm(self):
self.logger.out(
"Restarting VM", state="i", prefix="Domain {}".format(self.domuuid)
)
self.inrestart = True
# Start up a new Libvirt connection
libvirt_name = "qemu:///system"
lv_conn = libvirt.open(libvirt_name)
if lv_conn is None:
self.logger.out(
"Failed to open local libvirt connection",
state="e",
prefix="Domain {}".format(self.domuuid),
)
self.inrestart = False
return
self.shutdown_vm()
time.sleep(0.2)
self.start_vm()
self.addDomainToList()
self.zkhandler.write([(("domain.state", self.domuuid), "start")])
lv_conn.close()
self.inrestart = False
# Stop the VM forcibly without updating state
def terminate_vm(self):
self.logger.out(
"Terminating VM", state="i", prefix="Domain {}".format(self.domuuid)
)
self.instop = True
try:
self.dom.destroy()
time.sleep(0.2)
try:
if self.getdom().state()[0] == libvirt.VIR_DOMAIN_RUNNING:
# It didn't terminate, try again
self.dom.destroy()
except libvirt.libvirtError:
pass
except AttributeError:
self.logger.out(
"Failed to terminate VM",
state="e",
prefix="Domain {}".format(self.domuuid),
)
self.removeDomainFromList()
self.logger.out(
"Successfully terminated VM",
state="o",
prefix="Domain {}".format(self.domuuid),
)
self.dom = None
self.instop = False
# Stop the log watcher
self.console_log_instance.stop()
# Stop the VM forcibly
def stop_vm(self):
self.logger.out(
"Forcibly stopping VM", state="i", prefix="Domain {}".format(self.domuuid)
)
self.instop = True
try:
self.dom.destroy()
time.sleep(0.2)
try:
if self.getdom().state()[0] == libvirt.VIR_DOMAIN_RUNNING:
# It didn't terminate, try again
self.dom.destroy()
except libvirt.libvirtError:
pass
except AttributeError:
self.logger.out(
"Failed to stop VM", state="e", prefix="Domain {}".format(self.domuuid)
)
self.removeDomainFromList()
if self.inrestart is False:
self.zkhandler.write([(("domain.state", self.domuuid), "stop")])
self.logger.out(
"Successfully stopped VM",
state="o",
prefix="Domain {}".format(self.domuuid),
)
self.dom = None
self.instop = False
# Stop the log watcher
self.console_log_instance.stop()
# Shutdown the VM gracefully
def shutdown_vm(self):
self.logger.out(
"Gracefully stopping VM", state="i", prefix="Domain {}".format(self.domuuid)
)
is_aborted = False
self.inshutdown = True
self.dom.shutdown()
tick = 0
while True:
tick += 1
time.sleep(1)
# Abort shutdown if the state changes to start
current_state = self.zkhandler.read(("domain.state", self.domuuid))
if current_state not in ["shutdown", "restart", "migrate"]:
self.logger.out(
"Aborting VM shutdown due to state change",
state="i",
prefix="Domain {}".format(self.domuuid),
)
is_aborted = True
break
try:
lvdomstate = self.dom.state()[0]
except Exception:
lvdomstate = None
if lvdomstate != libvirt.VIR_DOMAIN_RUNNING:
self.removeDomainFromList()
self.zkhandler.write([(("domain.state", self.domuuid), "stop")])
self.logger.out(
"Successfully shutdown VM",
state="o",
prefix="Domain {}".format(self.domuuid),
)
self.dom = None
# Stop the log watcher
self.console_log_instance.stop()
break
if tick >= self.config["vm_shutdown_timeout"]:
self.logger.out(
"Shutdown timeout ({}s) expired, forcing off".format(
self.config["vm_shutdown_timeout"]
),
state="e",
prefix="Domain {}".format(self.domuuid),
)
self.zkhandler.write([(("domain.state", self.domuuid), "stop")])
break
self.inshutdown = False
if is_aborted:
self.manage_vm_state()
if self.inrestart:
# Wait to prevent race conditions
time.sleep(1)
self.zkhandler.write([(("domain.state", self.domuuid), "start")])
# Migrate the VM to a target host
def migrate_vm(self, force_live=False, force_shutdown=False):
# Wait for any previous migration
while self.inmigrate:
time.sleep(0.1)
if self.migration_method == "live":
force_live = True
elif self.migration_method == "shutdown":
force_shutdown = True
self.inmigrate = True
self.logger.out(
'Migrating VM to node "{}"'.format(self.node),
state="i",
prefix="Domain {}".format(self.domuuid),
)
# Used for sanity checking later
target_node = self.zkhandler.read(("domain.node", self.domuuid))
aborted = False
def abort_migrate(reason):
self.zkhandler.write(
[
(("domain.state", self.domuuid), "start"),
(("domain.node", self.domuuid), self.this_node.name),
(("domain.last_node", self.domuuid), self.last_lastnode),
]
)
migrate_lock_node.release()
migrate_lock_state.release()
self.inmigrate = False
self.logger.out(
"Aborted migration: {}".format(reason),
state="i",
prefix="Domain {}".format(self.domuuid),
)
# Acquire exclusive lock on the domain node key
migrate_lock_node = self.zkhandler.exclusivelock(("domain.node", self.domuuid))
migrate_lock_state = self.zkhandler.exclusivelock(
("domain.state", self.domuuid)
)
migrate_lock_node.acquire()
migrate_lock_state.acquire()
# Don't try to migrate a node to itself, set back to start
if self.node == self.lastnode or self.node == self.this_node.name:
abort_migrate(
"Target node matches the current active node during initial check"
)
return
time.sleep(0.5) # Initial delay for the first writer to grab the lock
def migrate_live():
self.logger.out(
"Setting up live migration",
state="i",
prefix="Domain {}".format(self.domuuid),
)
# Set up destination connection
dest_lv = "qemu+tcp://{}.{}/system".format(
self.node, self.config["cluster_domain"]
)
dest_tcp = "tcp://{}.{}".format(self.node, self.config["cluster_domain"])
try:
self.logger.out(
"Opening remote libvirt connection",
state="i",
prefix="Domain {}".format(self.domuuid),
)
# Open a connection to the destination
dest_lv_conn = libvirt.open(dest_lv)
if not dest_lv_conn:
raise
except Exception:
self.logger.out(
"Failed to open connection to {}; aborting live migration.".format(
dest_lv
),
state="e",
prefix="Domain {}".format(self.domuuid),
)
return False
try:
self.logger.out(
"Live migrating VM",
state="i",
prefix="Domain {}".format(self.domuuid),
)
# Send the live migration; force the destination URI to ensure we transit over the cluster network
target_dom = self.dom.migrate(
dest_lv_conn, libvirt.VIR_MIGRATE_LIVE, None, dest_tcp, 0
)
if not target_dom:
raise
except Exception as e:
self.logger.out(
"Failed to send VM to {} - aborting live migration; error: {}".format(
dest_lv, e
),
state="e",
prefix="Domain {}".format(self.domuuid),
)
dest_lv_conn.close()
return False
self.logger.out(
"Successfully migrated VM",
state="o",
prefix="Domain {}".format(self.domuuid),
)
dest_lv_conn.close()
self.console_log_instance.stop()
self.removeDomainFromList()
return True
def migrate_shutdown():
self.logger.out(
"Shutting down VM for offline migration",
state="i",
prefix="Domain {}".format(self.domuuid),
)
self.shutdown_vm()
return True
self.logger.out(
"Acquiring lock for migration phase B",
state="i",
prefix="Domain {}".format(self.domuuid),
)
lock = self.zkhandler.exclusivelock(("domain.migrate.sync_lock", self.domuuid))
try:
lock.acquire(timeout=30.0)
except Exception:
abort_migrate("Timed out waiting for peer")
return
self.logger.out(
"Acquired lock for migration phase B",
state="o",
prefix="Domain {}".format(self.domuuid),
)
migrate_live_result = False
# Do a final verification
if self.node == self.lastnode or self.node == self.this_node.name:
abort_migrate(
"Target node matches the current active node during final check"
)
return
if self.node != target_node:
abort_migrate("Target node changed during preparation")
return
if not force_shutdown:
# A live migrate is attemped 3 times in succession
ticks = 0
while True:
ticks += 1
self.logger.out(
"Attempting live migration try {}".format(ticks),
state="i",
prefix="Domain {}".format(self.domuuid),
)
migrate_live_result = migrate_live()
if migrate_live_result:
break
time.sleep(0.5)
if ticks > 2:
break
else:
migrate_live_result = False
if not migrate_live_result:
if force_live:
self.logger.out(
"Could not live migrate VM while live migration enforced",
state="e",
prefix="Domain {}".format(self.domuuid),
)
aborted = True
else:
migrate_shutdown()
if aborted:
abort_migrate("Live migration failed and is required")
return
self.last_currentnode = self.zkhandler.read(("domain.node", self.domuuid))
self.last_lastnode = self.zkhandler.read(("domain.last_node", self.domuuid))
migrate_lock_node.release()
migrate_lock_state.release()
lock.release()
self.inmigrate = False
return
# Receive the migration from another host
def receive_migrate(self):
# Wait for any previous migration
while self.inreceive:
time.sleep(0.1)
self.inreceive = True
self.logger.out(
'Receiving VM migration from node "{}"'.format(self.last_currentnode),
state="i",
prefix="Domain {}".format(self.domuuid),
)
# Ensure our lock key is populated
self.zkhandler.write(
[(("domain.migrate.sync_lock", self.domuuid), self.domuuid)]
)
self.logger.out(
"Acquiring lock for migration phase A",
state="i",
prefix="Domain {}".format(self.domuuid),
)
lock = self.zkhandler.exclusivelock(("domain.migrate.sync_lock", self.domuuid))
try:
lock.acquire(timeout=30.0)
except Exception:
self.logger.out("Failed to acquire exclusive lock for VM", state="w")
return
self.logger.out(
"Acquired lock for migration phase A",
state="o",
prefix="Domain {}".format(self.domuuid),
)
# Exactly twice the amount of time that the other side is waiting
time.sleep(1)
lock.release()
self.logger.out(
"Acquiring lock for phase C",
state="i",
prefix="Domain {}".format(self.domuuid),
)
lock.acquire()
self.logger.out(
"Acquired lock for migration phase C",
state="o",
prefix="Domain {}".format(self.domuuid),
)
# Set the updated data
self.last_currentnode = self.zkhandler.read(("domain.node", self.domuuid))
self.last_lastnode = self.zkhandler.read(("domain.last_node", self.domuuid))
self.state = self.zkhandler.read(("domain.state", self.domuuid))
self.dom = self.lookupByUUID(self.domuuid)
if self.dom:
lvdomstate = self.dom.state()[0]
if lvdomstate == libvirt.VIR_DOMAIN_RUNNING:
# VM has been received and started
self.addDomainToList()
self.zkhandler.write([(("domain.state", self.domuuid), "start")])
self.logger.out(
"Successfully received migrated VM",
state="o",
prefix="Domain {}".format(self.domuuid),
)
else:
# The receive somehow failed
self.zkhandler.write(
[
(("domain.state", self.domuuid), "fail"),
(
("domain.failed_reason", self.domuuid),
"Failed to receive migration",
),
]
)
self.logger.out(
"Failed to receive migrated VM",
state="e",
prefix="Domain {}".format(self.domuuid),
)
else:
if self.node == self.this_node.name:
if self.state in ["start"]:
# The receive was aborted
self.logger.out(
"Receive aborted via state change",
state="w",
prefix="Domain {}".format(self.domuuid),
)
elif self.state in ["stop"]:
# The send was shutdown-based
self.zkhandler.write([(("domain.state", self.domuuid), "start")])
else:
# The send failed or was aborted
self.logger.out(
"Migrate aborted or failed; VM in state {}".format(self.state),
state="w",
prefix="Domain {}".format(self.domuuid),
)
lock.release()
self.zkhandler.write([(("domain.migrate.sync_lock", self.domuuid), "")])
self.inreceive = False
return
#
# Main function to manage a VM (taking only self)
#
def manage_vm_state(self):
# Update the current values from zookeeper
self.state = self.zkhandler.read(("domain.state", self.domuuid))
self.node = self.zkhandler.read(("domain.node", self.domuuid))
self.lastnode = self.zkhandler.read(("domain.last_node", self.domuuid))
self.migration_method = self.zkhandler.read(
("domain.meta.migrate_method", self.domuuid)
)
# Check the current state of the VM
try:
if self.dom is not None:
running, reason = self.dom.state()
else:
raise
except Exception:
running = libvirt.VIR_DOMAIN_NOSTATE
self.logger.out(
'VM state change for "{}": {} {}'.format(
self.domuuid, self.state, self.node
),
state="i",
)
#######################
# Handle state changes
#######################
# Valid states are:
# start
# migrate
# migrate-live
# restart
# shutdown
# stop
# States we don't (need to) handle are:
# disable
# provision
# Conditional pass one - Are we already performing an action
if (
self.instart is False
and self.inrestart is False
and self.inmigrate is False
and self.inreceive is False
and self.inshutdown is False
and self.instop is False
):
# Conditional pass two - Is this VM configured to run on this node
if self.node == self.this_node.name:
# Conditional pass three - Is this VM currently running on this node
if running == libvirt.VIR_DOMAIN_RUNNING:
# VM is already running and should be
if self.state == "start":
# Start the log watcher
self.console_log_instance.start()
# Add domain to running list
self.addDomainToList()
# VM is already running and should be but stuck in migrate state
elif self.state == "migrate" or self.state == "migrate-live":
# Start the log watcher
self.console_log_instance.start()
self.zkhandler.write(
[(("domain.state", self.domuuid), "start")]
)
# Add domain to running list
self.addDomainToList()
# VM should be restarted
elif self.state == "restart":
self.restart_vm()
# VM should be shut down
elif self.state == "shutdown":
self.shutdown_vm()
# VM should be stopped
elif self.state == "stop":
self.stop_vm()
else:
# VM should be started
if self.state == "start":
# Start the domain
self.start_vm()
# VM should be migrated to this node
elif self.state == "migrate" or self.state == "migrate-live":
# Receive the migration
self.receive_migrate()
# VM should be restarted (i.e. started since it isn't running)
if self.state == "restart":
self.zkhandler.write(
[(("domain.state", self.domuuid), "start")]
)
# VM should be shut down; ensure it's gone from this node's domain_list
elif self.state == "shutdown":
self.removeDomainFromList()
# Stop the log watcher
self.console_log_instance.stop()
# VM should be stoped; ensure it's gone from this node's domain_list
elif self.state == "stop":
self.removeDomainFromList()
# Stop the log watcher
self.console_log_instance.stop()
# Update the VNC information
self.update_vnc()
else:
# Conditional pass three - Is this VM currently running on this node
if running == libvirt.VIR_DOMAIN_RUNNING:
# VM should be migrated away from this node
if self.state == "migrate":
self.migrate_vm(force_live=False)
# VM should be migrated away from this node, live only (no shutdown fallback)
elif self.state == "migrate-live":
self.migrate_vm(force_live=True)
# VM should be shutdown gracefully
elif self.state == "shutdown":
self.shutdown_vm()
# VM should be forcibly terminated
else:
self.terminate_vm()
self.state_thread = None
return
# This function is a wrapper for libvirt.lookupByUUID which fixes some problems
# 1. Takes a text UUID and handles converting it to bytes
# 2. Try's it and returns a sensible value if not
def lookupByUUID(self, tuuid):
# Don't do anything if the VM shouldn't live on this node
if self.node != self.this_node.name:
return None
lv_conn = None
libvirt_name = "qemu:///system"
# Convert the text UUID to bytes
buuid = uuid.UUID(tuuid).bytes
# Try
try:
# Open a libvirt connection
lv_conn = libvirt.open(libvirt_name)
if lv_conn is None:
self.logger.out(
"Failed to open local libvirt connection",
state="e",
prefix="Domain {}".format(self.domuuid),
)
return None
# Lookup the UUID
dom = lv_conn.lookupByUUID(buuid)
# Fail
except Exception:
dom = None
# After everything
finally:
# Close the libvirt connection
if lv_conn is not None:
lv_conn.close()
# Return the dom object (or None)
return dom