Listen for libvirt events

libvirt-listen-events.py

#!/usr/bin/python

import libvirt
import sys

# virDomainEventType is emitted during domain lifecycles (see libvirt.h)
VIR_DOMAIN_EVENT_MAPPING = {
    0: "VIR_DOMAIN_EVENT_DEFINED",
    1: "VIR_DOMAIN_EVENT_UNDEFINED",
    2: "VIR_DOMAIN_EVENT_STARTED",
    3: "VIR_DOMAIN_EVENT_SUSPENDED",
    4: "VIR_DOMAIN_EVENT_RESUMED",
    5: "VIR_DOMAIN_EVENT_STOPPED",
    6: "VIR_DOMAIN_EVENT_SHUTDOWN",
    7: "VIR_DOMAIN_EVENT_PMSUSPENDED",
}

# virDomainState
VIR_DOMAIN_STATE_MAPPING = {
    0: "VIR_DOMAIN_NOSTATE",
    1: "VIR_DOMAIN_RUNNING",
    2: "VIR_DOMAIN_BLOCKED",
    3: "VIR_DOMAIN_PAUSED",
    4: "VIR_DOMAIN_SHUTDOWN",
    5: "VIR_DOMAIN_SHUTOFF",
    6: "VIR_DOMAIN_CRASHED",
    7: "VIR_DOMAIN_PMSUSPENDED",
}

libvirt.virEventRegisterDefaultImpl()


def event_lifecycle_cb(conn, dom, event, detail, opaque):
    print ""
    print "=-" * 25
    print "%s: event: %s (%s)" % (dom.name(), VIR_DOMAIN_EVENT_MAPPING.get(event, "?"), event)
    print "%s: state: %s (%s)" % (dom.name(), VIR_DOMAIN_STATE_MAPPING.get(dom.state()[0], "?"), dom.state()[0])
    print "=-" * 25


def conn_register_event_id_lifecycle(conn):
    conn.domainEventRegisterAny(
        None,
        libvirt.VIR_DOMAIN_EVENT_ID_LIFECYCLE,
        event_lifecycle_cb,
        conn)

# setup connection
conn=libvirt.open("xen:///")
#conn=libvirt.open("qemu:///system")
if conn == None:
    print 'Failed to open connection to the hypervisor'
    sys.exit(1)

# register events
conn_register_event_id_lifecycle(conn)

# event loop
while True:
    libvirt.virEventRunDefaultImpl()


sys.exit(0)

anyone know what the performance on this is - is this the intended use case?

? This script was used to debug a problem with the libvirt+xen driver in OpenStack Nova. I was just interested in the events sent by libvirt. It's not about performance in any case...

thanks for reply, i am trying to build a socketsio layer on top of libvirtd but all approaches seem to be like this.