OpenStack Study: eventlet_backdoor.py

**** CubicPower OpenStack Study ****

def _dont_use_this():

    print("Don't use this, just disconnect instead")

**** CubicPower OpenStack Study ****

def _find_objects(t):

    return filter(lambda o: isinstance(o, t), gc.get_objects())

**** CubicPower OpenStack Study ****

def _print_greenthreads():

    for i, gt in enumerate(_find_objects(greenlet.greenlet)):

        print(i, gt)

        traceback.print_stack(gt.gr_frame)

        print()

**** CubicPower OpenStack Study ****

def _print_nativethreads():

    for threadId, stack in sys._current_frames().items():

        print(threadId)

        traceback.print_stack(stack)

        print()

**** CubicPower OpenStack Study ****

def initialize_if_enabled():

    backdoor_locals = {

        'exit': _dont_use_this,      # So we don't exit the entire process

        'quit': _dont_use_this,      # So we don't exit the entire process

        'fo': _find_objects,

        'pgt': _print_greenthreads,

        'pnt': _print_nativethreads,

    }

    if CONF.backdoor_port is None:

        return None

    # NOTE(johannes): The standard sys.displayhook will print the value of

    # the last expression and set it to __builtin__._, which overwrites

    # the __builtin__._ that gettext sets. Let's switch to using pprint

    # since it won't interact poorly with gettext, and it's easier to

    # read the output too.

    def displayhook(val):

        if val is not None:

            pprint.pprint(val)

    sys.displayhook = displayhook

    sock = eventlet.listen(('localhost', CONF.backdoor_port))

    port = sock.getsockname()[1]

    eventlet.spawn_n(eventlet.backdoor.backdoor_server, sock,

                     locals=backdoor_locals)

    return port