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pvc/node-daemon/pvcnoded/VMConsoleWatcherInstance.py

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Implement domain log watching Implements the ability for a client to watch almost-live domain console logs from the hypervisors. It does this using a deque-based "tail -f" mechanism (with a configurable buffer per-VM) that watches the domain console logfile in the (configurable) directory every half-second. It then stores the current buffer in Zookeeper when changed, where a client can then request it, either as a static piece of text in the `less` pager, or via a similar "tail -f" functionality implemented using fixed line splitting and comparison to provide a generally-seamless output. Enabling this feature requires each guest VM to implement a Libvirt serial log and write its (text) console to it, for example using the default logging directory: ``` <serial type='pty'> <log file='/var/log/libvirt/vmname.log' append='off'/> <serial> ``` The append mode can be either on or off; on grows files unbounded, off causes the log (and hence the PVC log data) to be truncated on initial VM startup from offline. The administrator must choose how they best want to handle this until Libvirt implements their own clog-type logging format.
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#!/usr/bin/env python3
Rename "Domain" to "VM" in various class names The name "Domain", though technically correct from a Libvirt perspective, was unnecessarily confusing. Call the class instances what they are, VMs.
2019-07-07 15:20:37 -04:00
# VMConsoleWatcherInstance.py - Class implementing a console log watcher for PVC domains
Implement domain log watching Implements the ability for a client to watch almost-live domain console logs from the hypervisors. It does this using a deque-based "tail -f" mechanism (with a configurable buffer per-VM) that watches the domain console logfile in the (configurable) directory every half-second. It then stores the current buffer in Zookeeper when changed, where a client can then request it, either as a static piece of text in the `less` pager, or via a similar "tail -f" functionality implemented using fixed line splitting and comparison to provide a generally-seamless output. Enabling this feature requires each guest VM to implement a Libvirt serial log and write its (text) console to it, for example using the default logging directory: ``` <serial type='pty'> <log file='/var/log/libvirt/vmname.log' append='off'/> <serial> ``` The append mode can be either on or off; on grows files unbounded, off causes the log (and hence the PVC log data) to be truncated on initial VM startup from offline. The administrator must choose how they best want to handle this until Libvirt implements their own clog-type logging format.
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# Part of the Parallel Virtual Cluster (PVC) system
#
Update copyright header year to 2020
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# Copyright (C) 2018-2020 Joshua M. Boniface <joshua@boniface.me>
Implement domain log watching Implements the ability for a client to watch almost-live domain console logs from the hypervisors. It does this using a deque-based "tail -f" mechanism (with a configurable buffer per-VM) that watches the domain console logfile in the (configurable) directory every half-second. It then stores the current buffer in Zookeeper when changed, where a client can then request it, either as a static piece of text in the `less` pager, or via a similar "tail -f" functionality implemented using fixed line splitting and comparison to provide a generally-seamless output. Enabling this feature requires each guest VM to implement a Libvirt serial log and write its (text) console to it, for example using the default logging directory: ``` <serial type='pty'> <log file='/var/log/libvirt/vmname.log' append='off'/> <serial> ``` The append mode can be either on or off; on grows files unbounded, off causes the log (and hence the PVC log data) to be truncated on initial VM startup from offline. The administrator must choose how they best want to handle this until Libvirt implements their own clog-type logging format.
2019-04-11 19:06:06 -04:00
#
# 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 time
Clean up imports Make several imports more specific to reduce redundant code imports and improve memory utilization.
2020-08-11 11:46:41 -04:00
from threading import Thread, Event
Implement domain log watching Implements the ability for a client to watch almost-live domain console logs from the hypervisors. It does this using a deque-based "tail -f" mechanism (with a configurable buffer per-VM) that watches the domain console logfile in the (configurable) directory every half-second. It then stores the current buffer in Zookeeper when changed, where a client can then request it, either as a static piece of text in the `less` pager, or via a similar "tail -f" functionality implemented using fixed line splitting and comparison to provide a generally-seamless output. Enabling this feature requires each guest VM to implement a Libvirt serial log and write its (text) console to it, for example using the default logging directory: ``` <serial type='pty'> <log file='/var/log/libvirt/vmname.log' append='off'/> <serial> ``` The append mode can be either on or off; on grows files unbounded, off causes the log (and hence the PVC log data) to be truncated on initial VM startup from offline. The administrator must choose how they best want to handle this until Libvirt implements their own clog-type logging format.
2019-04-11 19:06:06 -04:00
from collections import deque
Use consistent naming of components Rename "pvcd" to "pvcnoded", and "pvc-api" to "pvcapid" so names for the daemons are fully consistent. Update the names of the configuration files as well to match this new formatting. References #79
2020-02-08 19:16:19 -05:00
import pvcnoded.zkhandler as zkhandler
Implement domain log watching Implements the ability for a client to watch almost-live domain console logs from the hypervisors. It does this using a deque-based "tail -f" mechanism (with a configurable buffer per-VM) that watches the domain console logfile in the (configurable) directory every half-second. It then stores the current buffer in Zookeeper when changed, where a client can then request it, either as a static piece of text in the `less` pager, or via a similar "tail -f" functionality implemented using fixed line splitting and comparison to provide a generally-seamless output. Enabling this feature requires each guest VM to implement a Libvirt serial log and write its (text) console to it, for example using the default logging directory: ``` <serial type='pty'> <log file='/var/log/libvirt/vmname.log' append='off'/> <serial> ``` The append mode can be either on or off; on grows files unbounded, off causes the log (and hence the PVC log data) to be truncated on initial VM startup from offline. The administrator must choose how they best want to handle this until Libvirt implements their own clog-type logging format.
2019-04-11 19:06:06 -04:00
Lint: E302 expected 2 blank lines, found X
2020-11-07 14:45:24 -05:00
Rename "Domain" to "VM" in various class names The name "Domain", though technically correct from a Libvirt perspective, was unnecessarily confusing. Call the class instances what they are, VMs.
2019-07-07 15:20:37 -04:00
class VMConsoleWatcherInstance(object):
Implement domain log watching Implements the ability for a client to watch almost-live domain console logs from the hypervisors. It does this using a deque-based "tail -f" mechanism (with a configurable buffer per-VM) that watches the domain console logfile in the (configurable) directory every half-second. It then stores the current buffer in Zookeeper when changed, where a client can then request it, either as a static piece of text in the `less` pager, or via a similar "tail -f" functionality implemented using fixed line splitting and comparison to provide a generally-seamless output. Enabling this feature requires each guest VM to implement a Libvirt serial log and write its (text) console to it, for example using the default logging directory: ``` <serial type='pty'> <log file='/var/log/libvirt/vmname.log' append='off'/> <serial> ``` The append mode can be either on or off; on grows files unbounded, off causes the log (and hence the PVC log data) to be truncated on initial VM startup from offline. The administrator must choose how they best want to handle this until Libvirt implements their own clog-type logging format.
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# Initialization function
def __init__(self, domuuid, domname, zk_conn, config, logger, this_node):
self.domuuid = domuuid
self.domname = domname
self.zk_conn = zk_conn
self.config = config
self.logfile = '{}/{}.log'.format(config['console_log_directory'], self.domname)
self.console_log_lines = config['console_log_lines']
self.logger = logger
self.this_node = this_node
# Try to append (create) the logfile and set its permissions
open(self.logfile, 'a').close()
os.chmod(self.logfile, 0o600)
self.logdeque = deque(open(self.logfile), self.console_log_lines)
self.stamp = None
self.cached_stamp = None
# Set up the deque with the current contents of the log
self.last_loglines = None
self.loglines = None
# Thread options
self.thread = None
Clean up imports Make several imports more specific to reduce redundant code imports and improve memory utilization.
2020-08-11 11:46:41 -04:00
self.thread_stopper = Event()
Implement domain log watching Implements the ability for a client to watch almost-live domain console logs from the hypervisors. It does this using a deque-based "tail -f" mechanism (with a configurable buffer per-VM) that watches the domain console logfile in the (configurable) directory every half-second. It then stores the current buffer in Zookeeper when changed, where a client can then request it, either as a static piece of text in the `less` pager, or via a similar "tail -f" functionality implemented using fixed line splitting and comparison to provide a generally-seamless output. Enabling this feature requires each guest VM to implement a Libvirt serial log and write its (text) console to it, for example using the default logging directory: ``` <serial type='pty'> <log file='/var/log/libvirt/vmname.log' append='off'/> <serial> ``` The append mode can be either on or off; on grows files unbounded, off causes the log (and hence the PVC log data) to be truncated on initial VM startup from offline. The administrator must choose how they best want to handle this until Libvirt implements their own clog-type logging format.
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# Start execution thread
def start(self):
self.thread_stopper.clear()
Clean up imports Make several imports more specific to reduce redundant code imports and improve memory utilization.
2020-08-11 11:46:41 -04:00
self.thread = Thread(target=self.run, args=(), kwargs={})
Implement domain log watching Implements the ability for a client to watch almost-live domain console logs from the hypervisors. It does this using a deque-based "tail -f" mechanism (with a configurable buffer per-VM) that watches the domain console logfile in the (configurable) directory every half-second. It then stores the current buffer in Zookeeper when changed, where a client can then request it, either as a static piece of text in the `less` pager, or via a similar "tail -f" functionality implemented using fixed line splitting and comparison to provide a generally-seamless output. Enabling this feature requires each guest VM to implement a Libvirt serial log and write its (text) console to it, for example using the default logging directory: ``` <serial type='pty'> <log file='/var/log/libvirt/vmname.log' append='off'/> <serial> ``` The append mode can be either on or off; on grows files unbounded, off causes the log (and hence the PVC log data) to be truncated on initial VM startup from offline. The administrator must choose how they best want to handle this until Libvirt implements their own clog-type logging format.
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self.logger.out('Starting VM log parser', state='i', prefix='Domain {}:'.format(self.domuuid))
self.thread.start()
# Stop execution thread
def stop(self):
Only stop log parser if it's actually running
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if self.thread and self.thread.isAlive():
self.logger.out('Stopping VM log parser', state='i', prefix='Domain {}:'.format(self.domuuid))
self.thread_stopper.set()
# Do one final flush
self.update()
Implement domain log watching Implements the ability for a client to watch almost-live domain console logs from the hypervisors. It does this using a deque-based "tail -f" mechanism (with a configurable buffer per-VM) that watches the domain console logfile in the (configurable) directory every half-second. It then stores the current buffer in Zookeeper when changed, where a client can then request it, either as a static piece of text in the `less` pager, or via a similar "tail -f" functionality implemented using fixed line splitting and comparison to provide a generally-seamless output. Enabling this feature requires each guest VM to implement a Libvirt serial log and write its (text) console to it, for example using the default logging directory: ``` <serial type='pty'> <log file='/var/log/libvirt/vmname.log' append='off'/> <serial> ``` The append mode can be either on or off; on grows files unbounded, off causes the log (and hence the PVC log data) to be truncated on initial VM startup from offline. The administrator must choose how they best want to handle this until Libvirt implements their own clog-type logging format.
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# Main entrypoint
def run(self):
# Main loop
while not self.thread_stopper.is_set():
self.update()
time.sleep(0.5)
def update(self):
self.stamp = os.stat(self.logfile).st_mtime
if self.stamp != self.cached_stamp:
self.cached_stamp = self.stamp
self.fetch_lines()
# Update Zookeeper with the new loglines if they changed
if self.loglines != self.last_loglines:
Lint: E202 whitespace before '}'
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zkhandler.writedata(self.zk_conn, {'/domains/{}/consolelog'.format(self.domuuid): self.loglines})
Implement domain log watching Implements the ability for a client to watch almost-live domain console logs from the hypervisors. It does this using a deque-based "tail -f" mechanism (with a configurable buffer per-VM) that watches the domain console logfile in the (configurable) directory every half-second. It then stores the current buffer in Zookeeper when changed, where a client can then request it, either as a static piece of text in the `less` pager, or via a similar "tail -f" functionality implemented using fixed line splitting and comparison to provide a generally-seamless output. Enabling this feature requires each guest VM to implement a Libvirt serial log and write its (text) console to it, for example using the default logging directory: ``` <serial type='pty'> <log file='/var/log/libvirt/vmname.log' append='off'/> <serial> ``` The append mode can be either on or off; on grows files unbounded, off causes the log (and hence the PVC log data) to be truncated on initial VM startup from offline. The administrator must choose how they best want to handle this until Libvirt implements their own clog-type logging format.
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self.last_loglines = self.loglines
def fetch_lines(self):
self.logdeque = deque(open(self.logfile), self.console_log_lines)
self.loglines = ''.join(self.logdeque)