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Viewing changes to src/maasserver/service_monitor.py

  • Committer: Gavin Panella
  • Date: 2016-03-22 21:14:34 UTC
  • mfrom: (4657.1.157 maas)
  • Revision ID: gavin.panella@canonical.com-20160322211434-xzuovio86zvzo2js
Merge trunk.

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src/maasserver/service_monitor.py
 
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# Copyright 2016 Canonical Ltd.  This software is licensed under the
 
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# GNU Affero General Public License version 3 (see the file LICENSE).
 
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"""Services monitored on regiond."""
 
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__all__ = [
 
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    ]
 
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from datetime import timedelta
 
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from maasserver.models.regioncontrollerprocess import RegionControllerProcess
 
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from maasserver.models.service import Service
 
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from maasserver.utils.orm import transactional
 
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from maasserver.utils.threads import deferToDatabase
 
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from provisioningserver.config import is_dev_environment
 
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from provisioningserver.logger import get_maas_logger
 
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from provisioningserver.utils.service_monitor import (
 
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    AlwaysOnService,
 
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    ServiceMonitor,
 
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)
 
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from twisted.application.internet import TimerService
 
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from twisted.internet import reactor
 
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from twisted.internet.defer import inlineCallbacks
 
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from twisted.python import log
 
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maaslog = get_maas_logger("service_monitor_service")
 
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class BIND9Service(AlwaysOnService):
 
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    """Monitored bind9 service."""
 
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    name = "bind9"
 
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    service_name = "bind9"
 
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class ProxyService(AlwaysOnService):
 
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    """Monitored proxy service."""
 
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    name = "proxy"
 
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    service_name = "maas-proxy"
 
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# Global service monitor for regiond.
 
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service_monitor = ServiceMonitor(
 
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    BIND9Service(),
 
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    ProxyService(),
 
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)
 
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class ServiceMonitorService(TimerService, object):
 
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    """Service to monitor external services that the region requires."""
 
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    check_interval = timedelta(minutes=1).total_seconds()
 
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    def __init__(self, advertisingService, clock=reactor):
 
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        # Call self.monitorServices() every self.check_interval.
 
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        super(ServiceMonitorService, self).__init__(
 
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            self.check_interval, self.monitorServices)
 
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        self.clock = clock
 
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        self.advertisingService = advertisingService
 
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    def monitorServices(self):
 
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        """Monitors all of the external services and makes sure they
 
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        stay running.
 
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        """
 
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        if is_dev_environment():
 
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            log.msg(
 
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                "Skipping check of services; they're not running under "
 
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                "the supervision of systemd.")
 
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        else:
 
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            d = service_monitor.ensureServices()
 
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            d.addCallback(self._updateDatabase)
 
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            d.addErrback(
 
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                log.err, "Failed to monitor services and update database.")
 
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            return d
 
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    @inlineCallbacks
 
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    def _updateDatabase(self, services):
 
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        """Update database about services status."""
 
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        processId = yield self.advertisingService.processId.get()
 
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        services = yield self._buildServices(services)
 
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        yield deferToDatabase(self._saveIntoDatabase, processId, services)
 
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    @transactional
 
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    def _saveIntoDatabase(self, processId, services):
 
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        """Save the `services` in the the database for process by `processId`.
 
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        """
 
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        process = RegionControllerProcess.objects.get(id=processId)
 
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        for service in services:
 
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            Service.objects.update_service_for(
 
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                process.region, service["name"],
 
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                service["status"], service["status_info"])
 
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    @inlineCallbacks
 
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    def _buildServices(self, services):
 
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        """Build the list of services so they can be updated into the database.
 
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        """
 
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        msg_services = []
 
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        for name, state in services.items():
 
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            service = service_monitor.getServiceByName(name)
 
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            status, status_info = yield state.get_status_and_status_info_for(
 
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                service)
 
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            msg_services.append({
 
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                "name": name,
 
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                "status": status,
 
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                "status_info": status_info,
 
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            })
 
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        return msg_services