pvc/node-daemon/pvcd/NodeInstance.py

705 lines
30 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 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 subprocess
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):
# Passed-in variables on creation
self.name = name
self.this_node = this_node
self.zk_conn = zk_conn
self.config = config
self.logger = logger
# The IPMI hostname for fencing
self.ipmi_hostname = self.config['ipmi_hostname']
# 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
# Printable lists
self.active_node_list = []
self.flushed_node_list = []
self.inactive_node_list = []
self.network_list = []
self.domain_list = []
# Node resources
self.networks_count = 0
self.domains_count = 0
self.memused = 0
self.memfree = 0
self.memalloc = 0
self.vcpualloc = 0
# Flags
self.inflush = 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.router_state == 'primary':
self.become_primary()
else:
self.become_secondary()
@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:
if self.domain_state == 'flush' and self.inflush == False:
# Do flushing in a thread so it doesn't block the migrates out
flush_thread = threading.Thread(target=self.flush, args=(), kwargs={})
flush_thread.start()
if self.domain_state == 'unflush' and self.inflush == False:
self.unflush()
@self.zk_conn.DataWatch('/primary_node')
def watch_primary_node(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 = 'none'
if data != self.primary_node:
if self.daemon_mode == 'coordinator':
# We're a coordinator so we care about networking
if data == 'none':
# Toggle state management of routing functions
if self.name == self.this_node:
if self.daemon_state == 'run' and self.router_state != 'primary':
# Contend for primary
self.logger.out('Contending for primary routing state', state='i')
zkhandler.writedata(self.zk_conn, {'/primary_node': self.name })
elif data == self.this_node:
if self.name == self.this_node:
zkhandler.writedata(self.zk_conn, { '/nodes/{}/routerstate'.format(self.name): 'primary' })
self.primary_node = data
else:
if self.name == self.this_node:
zkhandler.writedata(self.zk_conn, { '/nodes/{}/routerstate'.format(self.name): 'secondary' })
self.primary_node = data
else:
self.primary_node = data
@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/{}/networkscount'.format(self.name))
def watch_node_networkscount(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.networks_count:
self.networks_count = 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
# Routing primary/secondary states
def become_secondary(self):
self.logger.out('Setting router {} to secondary state'.format(self.name), state='i')
self.logger.out('Network list: {}'.format(', '.join(self.network_list)))
time.sleep(1)
for network in self.d_network:
self.d_network[network].stopDHCPServer()
self.d_network[network].removeGatewayAddress()
self.dns_aggregator.stop_aggregator()
def become_primary(self):
self.logger.out('Setting router {} to primary state.'.format(self.name), state='i')
self.logger.out('Network list: {}'.format(', '.join(self.network_list)))
self.dns_aggregator.start_aggregator()
time.sleep(0.5)
# Start up the gateways and DHCP servers
for network in self.d_network:
self.d_network[network].createGatewayAddress()
self.d_network[network].startDHCPServer()
time.sleep(0.5)
# Handle AXFRs after to avoid slowdowns
for network in self.d_network:
self.dns_aggregator.get_axfr(network)
# Flush all VMs on the host
def flush(self):
self.inflush = True
self.logger.out('Flushing node "{}" of running VMs'.format(self.name), state='i')
self.logger.out('Domain list: {}'.format(', '.join(self.domain_list)))
fixed_domain_list = self.domain_list.copy()
for dom_uuid in fixed_domain_list:
self.logger.out('Selecting target to migrate VM "{}"'.format(dom_uuid), state='i')
current_node = zkhandler.readdata(self.zk_conn, '/domains/{}/node'.format(dom_uuid))
target_node = findTargetHypervisor(self.zk_conn, 'mem', dom_uuid)
if target_node == None:
self.logger.out('Failed to find migration target for VM "{}"; shutting down'.format(dom_uuid), state='e')
zkhandler.writedata(self.zk_conn, { '/domains/{}/state'.format(dom_uuid): 'shutdown' })
else:
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 True:
time.sleep(1)
vm_current_state = zkhandler.readdata(self.zk_conn, '/domains/{}/state'.format(dom_uuid))
if vm_current_state == "start":
break
zkhandler.writedata(self.zk_conn, { '/nodes/{}/runningdomains'.format(self.name): '' })
zkhandler.writedata(self.zk_conn, { '/nodes/{}/domainstate'.format(self.name): 'flushed' })
self.inflush = False
def unflush(self):
self.inflush = True
self.logger.out('Restoring node {} to active service.'.format(self.name), state='i')
zkhandler.writedata(self.zk_conn, { '/nodes/{}/domainstate'.format(self.name): 'ready' })
fixed_domain_list = self.d_domain.copy()
for dom_uuid in fixed_domain_list:
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): ''
})
self.inflush = False
def update_zookeeper(self):
# Connect to libvirt
libvirt_name = "qemu:///system"
lv_conn = libvirt.open(libvirt_name)
if lv_conn == None:
self.logger.out('Failed to open connection to "{}"'.format(libvirt_name), state='e')
return
# Get past state and update if needed
past_state = zkhandler.readdata(self.zk_conn, '/nodes/{}/daemonstate'.format(self.name))
if past_state != 'run':
self.daemon_state = 'run'
zkhandler.writedata(self.zk_conn, { '/nodes/{}/daemonstate'.format(self.name): 'run' })
else:
self.daemon_state = 'run'
# Ensure the primary key is properly set
if self.name == self.this_node:
if self.router_state == 'primary':
if zkhandler.readdata(self.zk_conn, '/primary_node') != self.name:
zkhandler.writedata(self.zk_conn, {'/primary_node': self.name})
# Toggle state management of dead VMs to restart them
memalloc = 0
vcpualloc = 0
for domain, instance in self.d_domain.items():
if domain in self.domain_list:
# Add the allocated memory to our memalloc value
memalloc += instance.getmemory()
vcpualloc += instance.getvcpus()
if instance.getstate() == 'start' and instance.getnode() == self.name:
if instance.getdom() != None:
try:
if instance.getdom().state()[0] != libvirt.VIR_DOMAIN_RUNNING:
raise
except Exception as e:
# Toggle a state "change"
zkhandler.writedata(self.zk_conn, { '/domains/{}/state'.format(domain): instance.getstate() })
# Ensure that any running VMs are readded to the domain_list
running_domains = lv_conn.listAllDomains(libvirt.VIR_CONNECT_LIST_DOMAINS_ACTIVE)
for domain in running_domains:
domain_uuid = domain.UUIDString()
if domain_uuid not in self.domain_list:
self.domain_list.append(domain_uuid)
# Set our information in zookeeper
#self.name = lv_conn.getHostname()
self.memused = int(psutil.virtual_memory().used / 1024 / 1024)
self.memfree = int(psutil.virtual_memory().free / 1024 / 1024)
self.memalloc = memalloc
self.vcpualloc = vcpualloc
self.cpuload = os.getloadavg()[0]
self.domains_count = len(lv_conn.listDomainsID())
keepalive_time = int(time.time())
try:
zkhandler.writedata(self.zk_conn, {
'/nodes/{}/memused'.format(self.name): str(self.memused),
'/nodes/{}/memfree'.format(self.name): str(self.memfree),
'/nodes/{}/memalloc'.format(self.name): str(self.memalloc),
'/nodes/{}/vcpualloc'.format(self.name): str(self.vcpualloc),
'/nodes/{}/cpuload'.format(self.name): str(self.cpuload),
'/nodes/{}/networkscount'.format(self.name): str(self.networks_count),
'/nodes/{}/domainscount'.format(self.name): str(self.domains_count),
'/nodes/{}/runningdomains'.format(self.name): ' '.join(self.domain_list),
'/nodes/{}/keepalive'.format(self.name): str(keepalive_time)
})
except:
self.logger.out('Failed to set keepalive data', state='e')
return
# Close the Libvirt connection
lv_conn.close()
# Display node information to the terminal
self.logger.out('{}{} keepalive{}'.format(self.logger.fmt_purple, self.name, self.logger.fmt_end), state='t')
self.logger.out(
'{bold}Domains:{nobold} {domcount} '
'{bold}Networks:{nobold} {netcount} '
'{bold}VM memory [MiB]:{nobold} {allocmem} '
'{bold}Free memory [MiB]:{nobold} {freemem} '
'{bold}Used memory [MiB]:{nobold} {usedmem} '
'{bold}Load:{nobold} {load}'.format(
bold=self.logger.fmt_bold,
nobold=self.logger.fmt_end,
domcount=self.domains_count,
freemem=self.memfree,
usedmem=self.memused,
load=self.cpuload,
allocmem=self.memalloc,
netcount=self.networks_count
),
)
# Update our local node lists
for node_name in self.d_node:
try:
node_daemon_state = zkhandler.readdata(self.zk_conn, '/nodes/{}/daemonstate'.format(node_name))
node_domain_state = zkhandler.readdata(self.zk_conn, '/nodes/{}/domainstate'.format(node_name))
node_keepalive = int(zkhandler.readdata(self.zk_conn, '/nodes/{}/keepalive'.format(node_name)))
except:
node_daemon_state = 'unknown'
node_domain_state = 'unknown'
node_keepalive = 0
# Handle deadtime and fencng if needed
# (A node is considered dead when its keepalive timer is >6*keepalive_interval seconds
# out-of-date while in 'start' state)
node_deadtime = int(time.time()) - ( int(self.config['keepalive_interval']) * int(self.config['fence_intervals']) )
if node_keepalive < node_deadtime and node_daemon_state == 'run':
self.logger.out('Node {} seems dead - starting monitor for fencing'.format(node_name), state='w')
zkhandler.writedata(self.zk_conn, { '/nodes/{}/daemonstate'.format(node_name): 'dead' })
fence_thread = threading.Thread(target=fenceNode, args=(node_name, self.zk_conn, self.config, self.logger), kwargs={})
fence_thread.start()
# Update the arrays
if node_daemon_state == 'run' and node_domain_state != 'flushed' and node_name not in self.active_node_list:
self.active_node_list.append(node_name)
try:
self.flushed_node_list.remove(node_name)
except ValueError:
pass
try:
self.inactive_node_list.remove(node_name)
except ValueError:
pass
if node_daemon_state != 'run' and node_domain_state != 'flushed' and node_name not in self.inactive_node_list:
self.inactive_node_list.append(node_name)
try:
self.active_node_list.remove(node_name)
except ValueError:
pass
try:
self.flushed_node_list.remove(node_name)
except ValueError:
pass
if node_domain_state == 'flushed' and node_name not in self.flushed_node_list:
self.flushed_node_list.append(node_name)
try:
self.active_node_list.remove(node_name)
except ValueError:
pass
try:
self.inactive_node_list.remove(node_name)
except ValueError:
pass
# List of the non-primary coordinators
secondary_node_list = self.config['coordinators'].split(',')
if secondary_node_list:
secondary_node_list.remove(self.primary_node)
for node in secondary_node_list:
if node in self.inactive_node_list:
secondary_node_list.remove(node)
# Display cluster information to the terminal
self.logger.out('{}Cluster status{}'.format(self.logger.fmt_purple, self.logger.fmt_end), state='t')
self.logger.out('{}Primary coordinator:{} {}'.format(self.logger.fmt_bold, self.logger.fmt_end, self.primary_node))
self.logger.out('{}Secondary coordinators:{} {}'.format(self.logger.fmt_bold, self.logger.fmt_end, ' '.join(secondary_node_list)))
self.logger.out('{}Active hypervisors:{} {}'.format(self.logger.fmt_bold, self.logger.fmt_end, ' '.join(self.active_node_list)))
self.logger.out('{}Flushed hypervisors:{} {}'.format(self.logger.fmt_bold, self.logger.fmt_end, ' '.join(self.flushed_node_list)))
self.logger.out('{}Inactive nodes:{} {}'.format(self.logger.fmt_bold, self.logger.fmt_end, ' '.join(self.inactive_node_list)))
#
# Find a migration target
#
def findTargetHypervisor(zk_conn, search_field, dom_uuid):
if search_field == 'mem':
return findTargetHypervisorMem(zk_conn, dom_uuid)
if search_field == 'load':
return findTargetHypervisorLoad(zk_conn, dom_uuid)
if search_field == 'vcpus':
return findTargetHypervisorVCPUs(zk_conn, dom_uuid)
if search_field == 'vms':
return findTargetHypervisorVMs(zk_conn, dom_uuid)
return None
# Get the list of valid target nodes
def getHypervisors(zk_conn, dom_uuid):
valid_node_list = []
full_node_list = zkhandler.listchildren(zk_conn, '/nodes')
current_node = zkhandler.readdata(zk_conn, '/domains/{}/node'.format(dom_uuid))
for node in full_node_list:
daemon_state = zkhandler.readdata(zk_conn, '/nodes/{}/daemonstate'.format(node))
domain_state = zkhandler.readdata(zk_conn, '/nodes/{}/domainstate'.format(node))
if node == current_node:
continue
if daemon_state != 'run' or domain_state != 'ready':
continue
valid_node_list.append(node)
return valid_node_list
# via free memory (relative to allocated memory)
def findTargetHypervisorMem(zk_conn, dom_uuid):
most_allocfree = 0
target_node = None
node_list = getHypervisors(zk_conn, dom_uuid)
for node in node_list:
memalloc = int(zkhandler.readdata(zk_conn, '/nodes/{}/memalloc'.format(node)))
memused = int(zkhandler.readdata(zk_conn, '/nodes/{}/memused'.format(node)))
memfree = int(zkhandler.readdata(zk_conn, '/nodes/{}/memfree'.format(node)))
memtotal = memused + memfree
allocfree = memtotal - memalloc
if allocfree > most_allocfree:
most_allocfree = allocfree
target_node = node
return target_node
# via load average
def findTargetHypervisorLoad(zk_conn, dom_uuid):
least_load = 9999
target_node = None
node_list = getHypervisors(zk_conn, dom_uuid)
for node in node_list:
load = int(zkhandler.readdata(zk_conn, '/nodes/{}/load'.format(node)))
if load < least_load:
least_load = load
target_hypevisor = node
return target_node
# via total vCPUs
def findTargetHypervisorVCPUs(zk_conn, dom_uuid):
least_vcpus = 9999
target_node = None
node_list = getHypervisors(zk_conn, dom_uuid)
for node in node_list:
vcpus = int(zkhandler.readdata(zk_conn, '/nodes/{}/vcpualloc'.format(node)))
if vcpus < least_vcpus:
least_vcpus = vcpus
target_node = node
return target_node
# via total VMs
def findTargetHypervisorVMs(zk_conn, dom_uuid):
least_vms = 9999
target_node = None
node_list = getHypervisors(zk_conn, dom_uuid)
for node in node_list:
vms = int(zkhandler.readdata(zk_conn, '/nodes/{}/domainscount'.format(node)))
if vms < least_vms:
least_vms = vms
target_node = node
return target_node
#
# Fence thread entry function
#
def fenceNode(node_name, zk_conn, config, logger):
failcount = 0
# We allow exactly 3 saving throws for the host to come back online
while failcount < 3:
# Wait 5 seconds
time.sleep(5)
# Get the state
node_daemon_state = zkhandler.readdata(zk_conn, '/nodes/{}/daemonstate'.format(node_name))
# Is it still 'dead'
if node_daemon_state == 'dead':
failcount += 1
logger.out('Node "{}" failed {} saving throws'.format(node_name, failcount), state='w')
# It changed back to something else so it must be alive
else:
logger.out('Node "{}" passed a saving throw; canceling fence'.format(node_name), state='o')
return
logger.out('Fencing node "{}" via IPMI reboot signal'.format(node_name), state='e')
# Get IPMI information
ipmi_hostname = zkhandler.readdata(zk_conn, '/nodes/{}/ipmihostname'.format(node_name))
ipmi_username = zkhandler.readdata(zk_conn, '/nodes/{}/ipmiusername'.format(node_name))
ipmi_password = zkhandler.readdata(zk_conn, '/nodes/{}/ipmipassword'.format(node_name))
# Shoot it in the head
fence_status = rebootViaIPMI(ipmi_hostname, ipmi_username, ipmi_password, logger)
# Hold to ensure the fence takes effect
time.sleep(3)
# Force into secondary network state if needed
if node_name in config['coordinators'].split(','):
zkhandler.writedata(zk_conn, { '/nodes/{}/routerstate'.format(node_name): 'secondary' })
if zkhandler.readdata(zk_conn, '/primary_node') == node_name:
zkhandler.writedata(zk_conn, { '/primary_node': 'none' })
# If the fence succeeded and successful_fence is migrate
if fence_status == True and config['successful_fence'] == 'migrate':
migrateFromFencedNode(zk_conn, node_name, logger)
# If the fence failed and failed_fence is migrate
if fence_status == False and config['failed_fence'] == 'migrate' and config['suicide_intervals'] != '0':
migrateFromFencedNode(zk_conn, node_name, logger)
# Migrate hosts away from a fenced node
def migrateFromFencedNode(zk_conn, node_name, logger):
logger.out('Moving VMs from dead node "{}" to new hosts'.format(node_name), state='i')
dead_node_running_domains = zkhandler.readdata(zk_conn, '/nodes/{}/runningdomains'.format(node_name)).split()
for dom_uuid in dead_node_running_domains:
target_node = findTargetHypervisor(zk_conn, 'mem', dom_uuid)
logger.out('Moving VM "{}" to node "{}"'.format(dom_uuid, target_node), state='i')
zkhandler.writedata(zk_conn, {
'/domains/{}/state'.format(dom_uuid): 'start',
'/domains/{}/node'.format(dom_uuid): target_node,
'/domains/{}/lastnode'.format(dom_uuid): node_name
})
# Set node in flushed state for easy remigrating when it comes back
zkhandler.writedata(zk_conn, { '/nodes/{}/domainstate'.format(node_name): 'flushed' })
#
# Perform an IPMI fence
#
def rebootViaIPMI(ipmi_hostname, ipmi_user, ipmi_password, logger):
ipmi_command = ['/usr/bin/ipmitool', '-I', 'lanplus', '-H', ipmi_hostname, '-U', ipmi_user, '-P', ipmi_password, 'chassis', 'power', 'reset']
ipmi_command_output = subprocess.run(ipmi_command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
if ipmi_command_output.returncode == 0:
logger.out('Successfully rebooted dead node', state='o')
return True
else:
logger.out('Failed to reboot dead node', state='e')
return False