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power.py 12.80 KiB
import collections
import functools
import json
import logging
import threading
import time
import traceback
from datetime import datetime
from enum import Enum
from typing import List, Callable, Optional, Dict
import pika
import pika.exceptions
from pydantic import BaseModel, validator
from pilab.events import utils
logger = logging.getLogger(__name__)
logging.getLogger("pika").setLevel(logging.WARNING)
class ActionType(str, Enum):
POWER_ON = "POWER_ON"
POWER_OFF = "POWER_OFF"
START_KERNEL = "START_KERNEL"
FETCH_WORKFLOW = "FETCH_WORKFLOW"
DOWNLOAD_IMAGE = "DOWNLOAD_IMAGE"
PRE_BOOT_CONFIG = "PRE_BOOT_CONFIGURATION"
BOOT_IMAGE = "BOOT_IMAGE"
CLOUD_INIT_CONFIG = "CLOUD_INIT_CONFIG"
ANSIBLE_CONFIG = "ANSIBLE_CONFIG"
class ActionState(str, Enum):
ACTION_SUCCESS = "ACTION_SUCCESS"
ACTION_IN_PROGRESS = "ACTION_IN_PROGRESS"
ACTION_FAILED = "ACTION_FAILED"
ACTION_PENDING = "ACTION_PENDING"
class Properties(BaseModel):
timestamp: float = None
configured: Optional[bool] = False
@validator("timestamp", pre=True, always=True)
def validate_date(cls, value, values):
return value or datetime.utcnow().timestamp()
class Action(BaseModel):
type: ActionType
state: ActionState
progress: Optional[int]
message: Optional[str]
class State(str, Enum):
INACTIVE = "INACTIVE"
PENDING = "PENDING"
ACTIVE = "ACTIVE"
FAILED = "FAILED"
class Event(BaseModel):
mac: str
state: State
action: Optional[Action]
properties: Properties
class Type(str, Enum):
controller = "controller"
pi = "pi"
switch = "switch"
def send_event(routing_key: str, event: Event):
try:
connection = utils.get_blocking_connection()
channel = connection.channel()
channel.queue_declare(
queue=routing_key,
durable=True,
exclusive=False,
auto_delete=False,
arguments={"x-queue-type": "stream"}
)
event_serialized = json.dumps(event.dict()).encode('utf-8')
channel.basic_publish(
exchange='',
routing_key=routing_key,
body=event_serialized)
connection.close()
except pika.exceptions.UnroutableError as e:
print(f'Could not send event to Broker; message {e}')
raise
except Exception as e:
logger.error(f'Error sending host event; message: {e}')
raise
def send_pi_event(mac: str, state: State, action: Action, props: Properties):
routing_key = f"host.pi.{mac}"
event = Event(
mac=mac,
state=state,
action=action,
properties=props
)
send_event(routing_key=routing_key, event=event)
def send_controller_event(mac: str, state: State):
routing_key = f"host.controller.{mac}"
event = Event(
mac=mac,
state=state,
properties=Properties()
)
send_event(routing_key=routing_key, event=event)
def send_switch_event(mac: str, state: State):
routing_key = f"host.switch.{mac}"
event = Event(
mac=mac,
state=state,
properties=Properties()
)
send_event(routing_key=routing_key, event=event)
class PowerConsumer(threading.Thread):
def __init__(self, queues: List[str], callback: Callable, type: Type, amqp_url: str = utils.BROKER_URL,
arguments: Dict = {"x-stream-offset": "last"}):
"""Create a new instance of the consumer class, passing in the AMQP
URL used to connect to RabbitMQ.
:param str amqp_url: The AMQP url to connect with
"""
super(PowerConsumer, self).__init__()
self.should_reconnect = False
self.was_consuming = False
self._connection = None
self._channel = None
self._closing = False
self._consumer_tags = []
self._url = amqp_url
self._consuming = False
# In production, experiment with higher prefetch values
# for higher consumer throughput
self._prefetch_count = 10
self.type = type
self.callback = callback
self.queues = queues
self.arguments = arguments
def connect(self):
"""This method connects to RabbitMQ, returning the connection handle.
When the connection is established, the on_connection_open method
will be invoked by pika.
:rtype: pika.SelectConnection
"""
logger.info('Connecting to %s', self._url)
return pika.SelectConnection(
parameters=pika.URLParameters(self._url),
on_open_callback=self.on_connection_open,
on_open_error_callback=self.on_connection_open_error,
on_close_callback=self.on_connection_closed)
def close_connection(self):
self._consuming = False
if self._connection.is_closing or self._connection.is_closed:
logger.info('Connection is closing or already closed')
else:
logger.info('Closing connection')
self._connection.close()
def on_connection_open(self, _unused_connection):
logger.debug('Connection opened')
self.open_channel()
def on_connection_open_error(self, _unused_connection, err):
logger.error('Connection open failed: %s', err)
self.reconnect()
def on_connection_closed(self, _unused_connection, reason):
self._channel = None
if self._closing:
self._connection.ioloop.stop()
else:
logger.warning('Connection closed, reconnect necessary: %s', reason)
self.reconnect()
def reconnect(self):
"""Will be invoked if the connection can't be opened or is
closed. Indicates that a reconnect is necessary then stops the
ioloop.
"""
self.should_reconnect = True
self.stop()
def open_channel(self):
logger.debug('Creating a new channel')
self._connection.channel(on_open_callback=self.on_channel_open)
def on_channel_open(self, channel):
logger.debug('Channel opened')
self._channel = channel
self._channel.add_on_close_callback(self.on_channel_closed)
self._channel.add_on_cancel_callback(self.on_consumer_cancelled)
for q in self.queues:
queue_name = f'host.{self.type.value}.{q}'
self.setup_queue(queue_name)
def on_channel_closed(self, channel, reason):
logger.warning('Channel %i was closed: %s', channel, reason)
self.close_connection()
def setup_queue(self, queue_name):
"""Setup the queue on RabbitMQ by invoking the Queue.Declare RPC
command. When it is complete, the on_queue_declareok method will
be invoked by pika.
:param str|unicode queue_name: The name of the queue to declare.
"""
logger.debug('Declaring queue %s', queue_name)
cb = functools.partial(self.on_queue_declareok, queue_name=queue_name)
self._channel.queue_declare(queue=queue_name,
durable=True,
exclusive=False,
auto_delete=False,
arguments={"x-queue-type": "stream"},
callback=cb)
def on_queue_declareok(self, _unused_frame, queue_name):
logger.info('Queue bound: %s', queue_name)
self.set_qos(queue_name)
def set_qos(self, queue_name):
cb = functools.partial(self.on_basic_qos_ok, queue_name=queue_name)
self._channel.basic_qos(
prefetch_count=self._prefetch_count, callback=cb)
def on_basic_qos_ok(self, _unused_frame, queue_name):
logger.debug('QOS set to: %d', self._prefetch_count)
self.start_consuming(queue_name)
def start_consuming(self, queue_name):
logger.debug('Issuing consumer related RPC commands')
_consumer_tag = self._channel.basic_consume(
queue_name,
self.on_message,
auto_ack=False,
arguments=self.arguments)
self._consumer_tags.append(_consumer_tag)
self.was_consuming = True
self._consuming = True
def on_consumer_cancelled(self, method_frame):
"""Invoked by pika when RabbitMQ sends a Basic.Cancel for a consumer
receiving messages.
:param pika.frame.Method method_frame: The Basic.Cancel frame
"""
logger.info('Consumer was cancelled remotely, shutting down: %r',
method_frame)
if self._channel:
self._channel.close()
def on_message(self, _unused_channel, basic_deliver, properties, body):
try:
event = Event.parse_obj(json.loads(body.decode('utf-8')))
self.callback(event)
self._channel.basic_ack(basic_deliver.delivery_tag)
logger.debug(f"Event processed successful")
except Exception as e:
traceback.print_exc()
logger.error(f"Failed to process Event; message {e}")
def stop_consuming(self):
"""Tell RabbitMQ that you would like to stop consuming by sending the
Basic.Cancel RPC command.
"""
if self._channel:
logger.debug('Sending a Basic.Cancel RPC command to RabbitMQ')
for tag in self._consumer_tags:
cb = functools.partial(self.on_cancelok, userdata=tag)
self._channel.basic_cancel(tag, cb)
def on_cancelok(self, _unused_frame, userdata):
self._consumer_tags.remove(userdata)
if not self._consumer_tags:
self._consuming = False
logger.info('RabbitMQ acknowledged the cancellation of all consumers')
self.close_channel()
def close_channel(self):
"""Call to close the channel with RabbitMQ cleanly by issuing the
Channel.Close RPC command.
"""
logger.info('Closing the channel')
self._channel.close()
def run(self):
while True:
try:
self._connection = self.connect()
self._connection.ioloop.start()
except (KeyboardInterrupt, SystemExit):
self.stop()
break
if not self.should_reconnect:
break
self._consuming = False
self._closing = False
time.sleep(1)
def stop(self):
"""Cleanly shutdown the connection to RabbitMQ by stopping the consumer
with RabbitMQ. When RabbitMQ confirms the cancellation, on_cancelok
will be invoked by pika, which will then closing the channel and
connection. The IOLoop is started again because this method is invoked
when CTRL-C is pressed raising a KeyboardInterrupt exception. This
exception stops the IOLoop which needs to be running for pika to
communicate with RabbitMQ. All of the commands issued prior to starting
the IOLoop will be buffered but not processed.
"""
if not self._closing:
self._closing = True
logger.debug('Stopping')
if self._consuming:
self.stop_consuming()
else:
self._connection.ioloop.stop()
logger.info('PowerConsumer stopped')
state: Dict[str, Event] = {}
custom_callback: Callable = None
pi_consumer: PowerConsumer = None
controller_consumer: PowerConsumer = None
switch_consumer: PowerConsumer = None
def event_callback(event: Event):
logger.debug(f"Received Power event: {event}")
if custom_callback:
custom_callback(event)
state[event.mac] = event
def run_restart_consumer(macs: List[str], _type: Type, callback: Callable = None):
global custom_callback, pi_consumer, controller_consumer, switch_consumer
custom_callback = callback
def restart_consumer(consumer: PowerConsumer):
if not consumer:
consumer = PowerConsumer(queues=macs, callback=event_callback, type=_type)
consumer.start()
logger.info(f'Restart power consumer for type {_type.value}')
return consumer
elif collections.Counter(consumer.queues) != collections.Counter(macs):
consumer.stop()
consumer.join()
consumer = PowerConsumer(queues=macs, callback=event_callback, type=_type)
consumer.start()
logger.info(f'Restart power consumer for type {_type.value}')
return consumer
else:
return consumer
match _type:
case Type.pi:
pi_consumer = restart_consumer(pi_consumer)
case Type.controller:
controller_consumer = restart_consumer(controller_consumer)
case Type.switch:
switch_consumer = restart_consumer(switch_consumer)
case _:
raise ValueError("Type is not known")
def get_latest_event(mac: str):
return state.get(mac)
def get_latest_state(mac: str):
event = state.get(mac)
return event.state if event else None