pvc/node-daemon/pvcd/fencing.py

108 lines
4.7 KiB
Python

#!/usr/bin/env python3
# fencing.py - PVC daemon function library, node fencing functions
# 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 threading
import time
import threading
import pvcd.zkhandler as zkhandler
import pvcd.common as common
#
# 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='w')
# 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 = '/usr/bin/ipmitool -I lanplus -H {} -U {} -P {} chassis power reset'.format(
ipmi_hostname, ipmi_user, ipmi_password
)
ipmi_command_retcode, ipmi_command_stdout, ipmi_command_stderr = common.run_os_command(ipmi_command)
if ipmi_command_retcode == 0:
logger.out('Successfully rebooted dead node', state='o')
return True
else:
logger.out('Failed to reboot dead node', state='e')
return False