pvc/node-daemon/pvcd/NodeInstance.py

715 lines
33 KiB
Python

#!/usr/bin/env python3
# NodeInstance.py - Class implementing a PVC node in pvcd
# Part of the Parallel Virtual Cluster (PVC) system
#
# Copyright (C) 2018-2020 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, either version 3 of the License, or
# (at your option) any later version.
#
# 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 os
import sys
import psutil
import socket
import time
import libvirt
import threading
import pvcd.log as log
import pvcd.zkhandler as zkhandler
import pvcd.common as common
class NodeInstance(object):
# Initialization function
def __init__(self, name, this_node, zk_conn, config, logger, d_node, d_network, d_domain, dns_aggregator, metadata_api):
# Passed-in variables on creation
self.name = name
self.this_node = this_node
self.zk_conn = zk_conn
self.config = config
self.logger = logger
# Which node is primary
self.primary_node = None
# States
self.daemon_mode = zkhandler.readdata(self.zk_conn, '/nodes/{}/daemonmode'.format(self.name))
self.daemon_state = 'stop'
self.router_state = 'client'
self.domain_state = 'ready'
# Object lists
self.d_node = d_node
self.d_network = d_network
self.d_domain = d_domain
self.dns_aggregator = dns_aggregator
self.metadata_api = metadata_api
# Printable lists
self.active_node_list = []
self.flushed_node_list = []
self.inactive_node_list = []
self.network_list = []
self.domain_list = []
# Node resources
self.domains_count = 0
self.memused = 0
self.memfree = 0
self.memalloc = 0
self.vcpualloc = 0
# Floating IP configurations
if self.config['enable_networking']:
self.vni_dev = self.config['vni_dev']
self.vni_ipaddr, self.vni_cidrnetmask = self.config['vni_floating_ip'].split('/')
self.upstream_dev = self.config['upstream_dev']
self.upstream_ipaddr, self.upstream_cidrnetmask = self.config['upstream_floating_ip'].split('/')
else:
self.vni_dev = None
self.vni_ipaddr = None
self.vni_cidrnetmask = None
self.upstream_dev = None
self.upstream_ipaddr = None
self.upstream_cidrnetmask = None
# Threads
self.flush_thread = None
# Flags
self.flush_stopper = False
# Zookeeper handlers for changed states
@self.zk_conn.DataWatch('/nodes/{}/daemonstate'.format(self.name))
def watch_node_daemonstate(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
try:
data = data.decode('ascii')
except AttributeError:
data = 'stop'
if data != self.daemon_state:
self.daemon_state = data
@self.zk_conn.DataWatch('/nodes/{}/routerstate'.format(self.name))
def watch_node_routerstate(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
try:
data = data.decode('ascii')
except AttributeError:
data = 'client'
if self.name == self.this_node and self.daemon_mode == 'coordinator':
# We're a coordinator so we care about networking
if data != self.router_state:
self.router_state = data
if self.config['enable_networking']:
if self.router_state == 'primary':
self.logger.out('Setting node {} to primary state'.format(self.name), state='i')
transition_thread = threading.Thread(target=self.become_primary, args=(), kwargs={})
transition_thread.start()
else:
# Skip becoming secondary unless already running
if self.daemon_state == 'run' or self.daemon_state == 'shutdown':
self.logger.out('Setting node {} to secondary state'.format(self.name), state='i')
transition_thread = threading.Thread(target=self.become_secondary, args=(), kwargs={})
transition_thread.start()
@self.zk_conn.DataWatch('/nodes/{}/domainstate'.format(self.name))
def watch_node_domainstate(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
try:
data = data.decode('ascii')
except AttributeError:
data = 'unknown'
if data != self.domain_state:
self.domain_state = data
# toggle state management of this node
if self.name == self.this_node:
# Stop any existing flush jobs
if self.flush_thread is not None:
self.logger.out('Waiting for previous migration to complete'.format(self.name), state='i')
self.flush_stopper = True
while self.flush_stopper:
time.sleep(0.1)
# Do flushing in a thread so it doesn't block the migrates out
if self.domain_state == 'flush':
self.flush_thread = threading.Thread(target=self.flush, args=(), kwargs={})
self.flush_thread.start()
# Do unflushing in a thread so it doesn't block the migrates in
if self.domain_state == 'unflush':
self.flush_thread = threading.Thread(target=self.unflush, args=(), kwargs={})
self.flush_thread.start()
@self.zk_conn.DataWatch('/nodes/{}/memfree'.format(self.name))
def watch_node_memfree(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
try:
data = data.decode('ascii')
except AttributeError:
data = 0
if data != self.memfree:
self.memfree = data
@self.zk_conn.DataWatch('/nodes/{}/memused'.format(self.name))
def watch_node_memused(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
try:
data = data.decode('ascii')
except AttributeError:
data = 0
if data != self.memused:
self.memused = data
@self.zk_conn.DataWatch('/nodes/{}/memalloc'.format(self.name))
def watch_node_memalloc(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
try:
data = data.decode('ascii')
except AttributeError:
data = 0
if data != self.memalloc:
self.memalloc = data
@self.zk_conn.DataWatch('/nodes/{}/vcpualloc'.format(self.name))
def watch_node_vcpualloc(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
try:
data = data.decode('ascii')
except AttributeError:
data = 0
if data != self.vcpualloc:
self.vcpualloc = data
@self.zk_conn.DataWatch('/nodes/{}/runningdomains'.format(self.name))
def watch_node_runningdomains(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
try:
data = data.decode('ascii').split()
except AttributeError:
data = []
if data != self.domain_list:
self.domain_list = data
@self.zk_conn.DataWatch('/nodes/{}/domainscount'.format(self.name))
def watch_node_domainscount(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
try:
data = data.decode('ascii')
except AttributeError:
data = 0
if data != self.domains_count:
self.domains_count = data
# Update value functions
def update_node_list(self, d_node):
self.d_node = d_node
def update_network_list(self, d_network):
self.d_network = d_network
network_list = []
for network in self.d_network:
network_list.append(d_network[network].vni)
self.network_list = network_list
def update_domain_list(self, d_domain):
self.d_domain = d_domain
######
# Phases of node transition
#
# Current Primary Candidate Secondary
# -> secondary -> primary
#
# def become_secondary() def become_primary()
#
# A ----------------------------------------------------------------- SYNC (candidate)
# B ----------------------------------------------------------------- SYNC (current)
# 1. Stop DNS aggregator ||
# 2. Stop DHCP servers ||
# 4a) network 1 ||
# 4b) network 2 ||
# etc. ||
# 3. Stop client API ||
# 4. Stop metadata API ||
# --
# C ----------------------------------------------------------------- SYNC (candidate)
# 5. Remove upstream floating IP 1. Add upstream floating IP ||
# --
# D ----------------------------------------------------------------- SYNC (candidate)
# 6. Remove cluster floating IP 2. Add cluster floating IP ||
# --
# E ----------------------------------------------------------------- SYNC (candidate)
# 7. Remove metadata floating IP 3. Add metadata floating IP ||
# --
# F ----------------------------------------------------------------- SYNC (candidate)
# 8. Remove gateway IPs 4. Add gateway IPs ||
# 8a) network 1 4a) network 1 ||
# 8b) network 2 4b) network 2 ||
# etc. etc. ||
# --
# G ----------------------------------------------------------------- SYNC (candidate)
# 5. Transition Patroni primary ||
# 6. Start client API ||
# 7. Start metadata API ||
# 8. Start DHCP servers ||
# 5a) network 1 ||
# 5b) network 2 ||
# etc. ||
# 9. Start DNS aggregator ||
# --
######
def become_primary(self):
"""
Acquire primary coordinator status from a peer node
"""
# Lock the primary node until transition is complete
primary_lock = zkhandler.writelock(self.zk_conn, '/primary_node')
primary_lock.acquire()
# Ensure our lock key is populated
zkhandler.writedata(self.zk_conn, {'/locks/primary_node': ''})
# Synchronize nodes A (I am writer)
lock = zkhandler.writelock(self.zk_conn, '/locks/primary_node')
self.logger.out('Acquiring write lock for synchronization A', state='i')
lock.acquire()
self.logger.out('Acquired write lock for synchronization A', state='o')
time.sleep(1) # Time for reader to acquire the lock
self.logger.out('Releasing write lock for synchronization A', state='i')
zkhandler.writedata(self.zk_conn, {'/locks/primary_node': ''})
lock.release()
self.logger.out('Released write lock for synchronization A', state='o')
time.sleep(0.1) # Time for new writer to acquire the lock
# Synchronize nodes B (I am reader)
lock = zkhandler.readlock(self.zk_conn, '/locks/primary_node')
self.logger.out('Acquiring read lock for synchronization B', state='i')
lock.acquire()
self.logger.out('Acquired read lock for synchronization B', state='o')
self.logger.out('Releasing read lock for synchronization B', state='i')
lock.release()
self.logger.out('Released read lock for synchronization B', state='o')
# Synchronize nodes C (I am writer)
lock = zkhandler.writelock(self.zk_conn, '/locks/primary_node')
self.logger.out('Acquiring write lock for synchronization C', state='i')
lock.acquire()
self.logger.out('Acquired write lock for synchronization C', state='o')
time.sleep(0.5) # Time for reader to acquire the lock
# 1. Add Upstream floating IP
self.logger.out(
'Creating floating upstream IP {}/{} on interface {}'.format(
self.upstream_ipaddr,
self.upstream_cidrnetmask,
'brupstream'
),
state='o'
)
common.createIPAddress(self.upstream_ipaddr, self.upstream_cidrnetmask, 'brupstream')
self.logger.out('Releasing write lock for synchronization C', state='i')
zkhandler.writedata(self.zk_conn, {'/locks/primary_node': ''})
lock.release()
self.logger.out('Released write lock for synchronization C', state='o')
# Synchronize nodes D (I am writer)
lock = zkhandler.writelock(self.zk_conn, '/locks/primary_node')
self.logger.out('Acquiring write lock for synchronization D', state='i')
lock.acquire()
self.logger.out('Acquired write lock for synchronization D', state='o')
time.sleep(0.2) # Time for reader to acquire the lock
# 2. Add Cluster floating IP
self.logger.out(
'Creating floating management IP {}/{} on interface {}'.format(
self.vni_ipaddr,
self.vni_cidrnetmask,
'brcluster'
),
state='o'
)
common.createIPAddress(self.vni_ipaddr, self.vni_cidrnetmask, 'brcluster')
self.logger.out('Releasing write lock for synchronization D', state='i')
zkhandler.writedata(self.zk_conn, {'/locks/primary_node': ''})
lock.release()
self.logger.out('Released write lock for synchronization D', state='o')
# Synchronize nodes E (I am writer)
lock = zkhandler.writelock(self.zk_conn, '/locks/primary_node')
self.logger.out('Acquiring write lock for synchronization E', state='i')
lock.acquire()
self.logger.out('Acquired write lock for synchronization E', state='o')
time.sleep(0.2) # Time for reader to acquire the lock
# 3. Add Metadata link-local IP
self.logger.out(
'Creating Metadata link-local IP {}/{} on interface {}'.format(
'169.254.169.254',
'32',
'lo'
),
state='o'
)
common.createIPAddress('169.254.169.254', '32', 'lo')
self.logger.out('Releasing write lock for synchronization E', state='i')
zkhandler.writedata(self.zk_conn, {'/locks/primary_node': ''})
lock.release()
self.logger.out('Released write lock for synchronization E', state='o')
# Synchronize nodes F (I am writer)
lock = zkhandler.writelock(self.zk_conn, '/locks/primary_node')
self.logger.out('Acquiring write lock for synchronization F', state='i')
lock.acquire()
self.logger.out('Acquired write lock for synchronization F', state='o')
time.sleep(0.2) # Time for reader to acquire the lock
# 4. Add gateway IPs
for network in self.d_network:
self.d_network[network].createGateways()
self.logger.out('Releasing write lock for synchronization F', state='i')
zkhandler.writedata(self.zk_conn, {'/locks/primary_node': ''})
lock.release()
self.logger.out('Released write lock for synchronization F', state='o')
# Synchronize nodes G (I am writer)
lock = zkhandler.writelock(self.zk_conn, '/locks/primary_node')
self.logger.out('Acquiring write lock for synchronization G', state='i')
lock.acquire()
self.logger.out('Acquired write lock for synchronization G', state='o')
time.sleep(0.2) # Time for reader to acquire the lock
# 5. Transition Patroni primary
self.logger.out('Setting Patroni leader to this node', state='i')
tick = 1
patroni_failed = True
# As long as we're primary, keep trying to set the Patroni leader to us
while self.router_state == 'primary':
# Switch Patroni leader to the local instance
retcode, stdout, stderr = common.run_os_command(
"""
patronictl
-c /etc/patroni/config.yml
-d zookeeper://localhost:2181
switchover
--candidate {}
--force
pvc
""".format(self.name)
)
# Combine the stdout and stderr and strip the output
# Patronictl's output is pretty junky
if stderr:
stdout += stderr
stdout = stdout.strip()
# Handle our current Patroni leader being us
if stdout and stdout.split('\n')[-1].split() == ["Error:", "Switchover", "target", "and", "source", "are", "the", "same."]:
self.logger.out('Failed to switch Patroni leader to ourselves; this is fine\n{}'.format(stdout), state='w')
break
# Handle a failed switchover
elif stdout and (stdout.split('\n')[-1].split()[:2] == ["Switchover", "failed,"] or stdout.strip().split('\n')[-1].split()[:1] == ["Error"]):
if tick > 4:
self.logger.out('Failed to switch Patroni leader after 5 tries; aborting', state='e')
break
else:
self.logger.out('Failed to switch Patroni leader; retrying [{}/5]\n{}\n'.format(tick, stdout), state='e')
tick += 1
time.sleep(5)
# Otherwise, we succeeded
else:
self.logger.out('Successfully switched Patroni leader\n{}'.format(stdout), state='o')
patroni_failed = False
time.sleep(0.2)
break
# 6. Start client API (and provisioner worker)
if self.config['enable_api']:
self.logger.out('Starting PVC API client service', state='i')
common.run_os_command("systemctl start pvc-api.service")
self.logger.out('Starting PVC Provisioner Worker service', state='i')
common.run_os_command("systemctl start pvc-provisioner-worker.service")
# 7. Start metadata API; just continue if we fail
self.metadata_api.start()
# 8. Start DHCP servers
for network in self.d_network:
self.d_network[network].startDHCPServer()
# 9. Start DNS aggregator; just continue if we fail
if not patroni_failed:
self.dns_aggregator.start_aggregator()
else:
self.logger.out('Not starting DNS aggregator due to Patroni failures', state='e')
self.logger.out('Releasing write lock for synchronization G', state='i')
zkhandler.writedata(self.zk_conn, {'/locks/primary_node': ''})
lock.release()
self.logger.out('Released write lock for synchronization G', state='o')
primary_lock.release()
self.logger.out('Node {} transitioned to primary state'.format(self.name), state='o')
def become_secondary(self):
"""
Relinquish primary coordinator status to a peer node
"""
time.sleep(0.2) # Initial delay for the first writer to grab the lock
# Synchronize nodes A (I am reader)
lock = zkhandler.readlock(self.zk_conn, '/locks/primary_node')
self.logger.out('Acquiring read lock for synchronization A', state='i')
lock.acquire()
self.logger.out('Acquired read lock for synchronization A', state='o')
self.logger.out('Releasing read lock for synchronization A', state='i')
lock.release()
self.logger.out('Released read lock for synchronization A', state='o')
# Synchronize nodes B (I am writer)
lock = zkhandler.writelock(self.zk_conn, '/locks/primary_node')
self.logger.out('Acquiring write lock for synchronization B', state='i')
lock.acquire()
self.logger.out('Acquired write lock for synchronization B', state='o')
time.sleep(0.2) # Time for reader to acquire the lock
# 1. Stop DNS aggregator
self.dns_aggregator.stop_aggregator()
# 2. Stop DHCP servers
for network in self.d_network:
self.d_network[network].stopDHCPServer()
self.logger.out('Releasing write lock for synchronization B', state='i')
zkhandler.writedata(self.zk_conn, {'/locks/primary_node': ''})
lock.release()
self.logger.out('Released write lock for synchronization B', state='o')
# 3. Stop client API
if self.config['enable_api']:
self.logger.out('Stopping PVC API client service', state='i')
common.run_os_command("systemctl stop pvc-api.service")
# 4. Stop metadata API
self.metadata_api.stop()
time.sleep(0.1) # Time for new writer to acquire the lock
# Synchronize nodes C (I am reader)
lock = zkhandler.readlock(self.zk_conn, '/locks/primary_node')
self.logger.out('Acquiring read lock for synchronization C', state='i')
lock.acquire()
self.logger.out('Acquired read lock for synchronization C', state='o')
# 5. Remove Upstream floating IP
self.logger.out(
'Removing floating upstream IP {}/{} from interface {}'.format(
self.upstream_ipaddr,
self.upstream_cidrnetmask,
'brupstream'
),
state='o'
)
common.removeIPAddress(self.upstream_ipaddr, self.upstream_cidrnetmask, 'brupstream')
self.logger.out('Releasing read lock for synchronization C', state='i')
lock.release()
self.logger.out('Released read lock for synchronization C', state='o')
# Synchronize nodes D (I am reader)
lock = zkhandler.readlock(self.zk_conn, '/locks/primary_node')
self.logger.out('Acquiring read lock for synchronization D', state='i')
lock.acquire()
self.logger.out('Acquired read lock for synchronization D', state='o')
# 6. Remove Cluster floating IP
self.logger.out(
'Removing floating management IP {}/{} from interface {}'.format(
self.vni_ipaddr,
self.vni_cidrnetmask,
'brcluster'
),
state='o'
)
common.removeIPAddress(self.vni_ipaddr, self.vni_cidrnetmask, 'brcluster')
self.logger.out('Releasing read lock for synchronization D', state='i')
lock.release()
self.logger.out('Released read lock for synchronization D', state='o')
# Synchronize nodes E (I am reader)
lock = zkhandler.readlock(self.zk_conn, '/locks/primary_node')
self.logger.out('Acquiring read lock for synchronization E', state='i')
lock.acquire()
self.logger.out('Acquired read lock for synchronization E', state='o')
# 7. Remove Metadata link-local IP
self.logger.out(
'Removing Metadata link-local IP {}/{} from interface {}'.format(
'169.254.169.254',
'32',
'lo'
),
state='o'
)
common.removeIPAddress('169.254.169.254', '32', 'lo')
self.logger.out('Releasing read lock for synchronization E', state='i')
lock.release()
self.logger.out('Released read lock for synchronization E', state='o')
# Synchronize nodes F (I am reader)
lock = zkhandler.readlock(self.zk_conn, '/locks/primary_node')
self.logger.out('Acquiring read lock for synchronization F', state='i')
lock.acquire()
self.logger.out('Acquired read lock for synchronization F', state='o')
# 8. Remove gateway IPs
for network in self.d_network:
self.d_network[network].removeGateways()
self.logger.out('Releasing read lock for synchronization F', state='i')
lock.release()
self.logger.out('Released read lock for synchronization F', state='o')
# Synchronize nodes G (I am reader)
lock = zkhandler.readlock(self.zk_conn, '/locks/primary_node')
self.logger.out('Acquiring read lock for synchronization G', state='i')
try:
lock.acquire(timeout=60) # Don't wait forever and completely block us
self.logger.out('Acquired read lock for synchronization G', state='o')
except:
pass
self.logger.out('Releasing read lock for synchronization G', state='i')
lock.release()
self.logger.out('Released read lock for synchronization G', state='o')
self.logger.out('Node {} transitioned to secondary state'.format(self.name), state='o')
# Flush all VMs on the host
def flush(self):
# Begin flush
self.logger.out('Flushing node "{}" of running VMs'.format(self.name), state='i')
self.logger.out('VM list: {}'.format(', '.join(self.domain_list)), state='i')
fixed_domain_list = self.domain_list.copy()
for dom_uuid in fixed_domain_list:
# Allow us to cancel the operation
if self.flush_stopper:
self.logger.out('Aborting node flush'.format(self.name), state='i')
self.flush_thread = None
self.flush_stopper = False
return
self.logger.out('Selecting target to migrate VM "{}"'.format(dom_uuid), state='i')
target_node = common.findTargetNode(self.zk_conn, self.config, dom_uuid)
# Don't replace the previous node if the VM is already migrated
if zkhandler.readdata(self.zk_conn, '/domains/{}/lastnode'.format(dom_uuid)):
current_node = zkhandler.readdata(self.zk_conn, '/domains/{}/lastnode'.format(dom_uuid))
else:
current_node = zkhandler.readdata(self.zk_conn, '/domains/{}/node'.format(dom_uuid))
if target_node is None:
self.logger.out('Failed to find migration target for VM "{}"; shutting down and setting autostart flag'.format(dom_uuid), state='e')
zkhandler.writedata(self.zk_conn, { '/domains/{}/state'.format(dom_uuid): 'shutdown' })
zkhandler.writedata(self.zk_conn, { '/domains/{}/node_autostart'.format(dom_uuid): 'True' })
# Wait for the VM to shut down
while zkhandler.readdata(self.zk_conn, '/domains/{}/state'.format(dom_uuid)) in ['shutdown']:
time.sleep(0.1)
continue
self.logger.out('Migrating VM "{}" to node "{}"'.format(dom_uuid, target_node), state='i')
zkhandler.writedata(self.zk_conn, {
'/domains/{}/state'.format(dom_uuid): 'migrate',
'/domains/{}/node'.format(dom_uuid): target_node,
'/domains/{}/lastnode'.format(dom_uuid): current_node
})
# Wait for the VM to migrate so the next VM's free RAM count is accurate (they migrate in serial anyways)
while zkhandler.readdata(self.zk_conn, '/domains/{}/state'.format(dom_uuid)) in ['migrate', 'unmigrate', 'shutdown']:
time.sleep(0.1)
zkhandler.writedata(self.zk_conn, { '/nodes/{}/runningdomains'.format(self.name): '' })
zkhandler.writedata(self.zk_conn, { '/nodes/{}/domainstate'.format(self.name): 'flushed' })
self.flush_thread = None
self.flush_stopper = False
return
def unflush(self):
self.logger.out('Restoring node {} to active service.'.format(self.name), state='i')
fixed_domain_list = self.d_domain.copy()
for dom_uuid in fixed_domain_list:
# Allow us to cancel the operation
if self.flush_stopper:
self.logger.out('Aborting node unflush'.format(self.name), state='i')
self.flush_thread = None
self.flush_stopper = False
return
# Handle autostarts
autostart = zkhandler.readdata(self.zk_conn, '/domains/{}/node_autostart'.format(dom_uuid))
node = zkhandler.readdata(self.zk_conn, '/domains/{}/node'.format(dom_uuid))
if autostart == 'True' and node == self.name:
self.logger.out('Starting autostart VM "{}"'.format(dom_uuid), state='i')
zkhandler.writedata(self.zk_conn, {
'/domains/{}/state'.format(dom_uuid): 'start',
'/domains/{}/node'.format(dom_uuid): self.name,
'/domains/{}/lastnode'.format(dom_uuid): '',
'/domains/{}/node_autostart'.format(dom_uuid): 'False'
})
continue
try:
last_node = zkhandler.readdata(self.zk_conn, '/domains/{}/lastnode'.format(dom_uuid))
except:
continue
if last_node != self.name:
continue
self.logger.out('Setting unmigration for VM "{}"'.format(dom_uuid), state='i')
zkhandler.writedata(self.zk_conn, {
'/domains/{}/state'.format(dom_uuid): 'migrate',
'/domains/{}/node'.format(dom_uuid): self.name,
'/domains/{}/lastnode'.format(dom_uuid): ''
})
# Wait for the VM to migrate back
while zkhandler.readdata(self.zk_conn, '/domains/{}/state'.format(dom_uuid)) in ['migrate', 'unmigrate', 'shutdown']:
time.sleep(0.1)
zkhandler.writedata(self.zk_conn, { '/nodes/{}/domainstate'.format(self.name): 'ready' })
self.flush_thread = None
self.flush_stopper = False
return