On Wed, Feb 15, 2012 at 09:11:32PM -0500, Dave Allan wrote:

Hi all,

A while back I wrote the attached code to demonstrate how to use events and serial console to create a serial console that stays up even when the VM is down. Is it worth adding to the examples? It might need some work, as I am not terribly strong with Python.

Dave

I was just going through some old mail and realized that I don't think this ever got a response. Anybody have any thoughts on it? Dave

#!/usr/bin/python -u import sys, os, logging, libvirt, tty, termios, atexit

def reset_term(): termios.tcsetattr(0, termios.TCSADRAIN, attrs)

def error_handler(unused, error): # The console stream errors on VM shutdown; we don't care if (error[0] == libvirt.VIR_ERR_RPC and error[1] == libvirt.VIR_FROM_STREAMS): return logging.warn(error)

class Console(object): def __init__(self, uri, uuid): self.uri = uri self.uuid = uuid self.connection = libvirt.open(uri) self.domain = self.connection.lookupByUUIDString(uuid) self.state = self.domain.state(0) self.connection.domainEventRegister(lifecycle_callback, self) self.stream = None self.run_console = True logging.info("%s initial state %d, reason %d", self.uuid, self.state[0], self.state[1])

def check_console(console): if (console.state[0] == libvirt.VIR_DOMAIN_RUNNING or console.state[0] == libvirt.VIR_DOMAIN_PAUSED): if console.stream == None: console.stream = console.connection.newStream(libvirt.VIR_STREAM_NONBLOCK) console.domain.openConsole(None, console.stream, 0) console.stream.eventAddCallback(libvirt.VIR_STREAM_EVENT_READABLE, stream_callback, console) else: if console.stream: console.stream.eventRemoveCallback() console.stream = None

return console.run_console

def stdin_callback(watch, fd, events, console): readbuf = os.read(fd, 1024) if readbuf.startswith(""): console.run_console = False return if console.stream: console.stream.send(readbuf)

def stream_callback(stream, events, console): try: received_data = console.stream.recv(1024) except: return os.write(0, received_data)

def lifecycle_callback (connection, domain, event, detail, console): console.state = console.domain.state(0) logging.info("%s transitioned to state %d, reason %d", console.uuid, console.state[0], console.state[1])

# main if len(sys.argv) != 3: print "Usage:", sys.argv[0], "URI UUID" print "for example:", sys.argv[0], "'qemu:///system' '32ad945f-7e78-c33a-e96d-39f25e025d81'" sys.exit(1)

uri = sys.argv[1] uuid = sys.argv[2]

print "Escape character is ^]" logging.basicConfig(filename='msg.log', level=logging.DEBUG) logging.info("URI: %s", uri) logging.info("UUID: %s", uuid)

libvirt.virEventRegisterDefaultImpl() libvirt.registerErrorHandler(error_handler, None)

atexit.register(reset_term) attrs = termios.tcgetattr(0) tty.setraw(0)

console = Console(uri, uuid) console.stdin_watch = libvirt.virEventAddHandle(0, libvirt.VIR_EVENT_HANDLE_READABLE, stdin_callback, console)

while check_console(console): libvirt.virEventRunDefaultImpl()