101 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			101 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
"""Outpost websocket handler"""
 | 
						|
from dataclasses import asdict, dataclass, field
 | 
						|
from enum import IntEnum
 | 
						|
from time import time
 | 
						|
from typing import Any, Dict
 | 
						|
 | 
						|
from channels.generic.websocket import JsonWebsocketConsumer
 | 
						|
from dacite import from_dict
 | 
						|
from dacite.data import Data
 | 
						|
from django.core.cache import cache
 | 
						|
from django.core.exceptions import ValidationError
 | 
						|
from structlog import get_logger
 | 
						|
 | 
						|
from passbook.core.models import Token, TokenIntents
 | 
						|
from passbook.outposts.models import Outpost
 | 
						|
 | 
						|
LOGGER = get_logger()
 | 
						|
 | 
						|
 | 
						|
class WebsocketMessageInstruction(IntEnum):
 | 
						|
    """Commands which can be triggered over Websocket"""
 | 
						|
 | 
						|
    # Simple message used by either side when a message is acknowledged
 | 
						|
    ACK = 0
 | 
						|
 | 
						|
    # Message used by outposts to report their alive status
 | 
						|
    HELLO = 1
 | 
						|
 | 
						|
    # Message sent by us to trigger an Update
 | 
						|
    TRIGGER_UPDATE = 2
 | 
						|
 | 
						|
 | 
						|
@dataclass
 | 
						|
class WebsocketMessage:
 | 
						|
    """Complete Websocket Message that is being sent"""
 | 
						|
 | 
						|
    instruction: int
 | 
						|
    args: Dict[str, Any] = field(default_factory=dict)
 | 
						|
 | 
						|
 | 
						|
class OutpostConsumer(JsonWebsocketConsumer):
 | 
						|
    """Handler for Outposts that connect over websockets for health checks and live updates"""
 | 
						|
 | 
						|
    outpost: Outpost
 | 
						|
 | 
						|
    def connect(self):
 | 
						|
        # TODO: This authentication block could be handeled in middleware
 | 
						|
        headers = dict(self.scope["headers"])
 | 
						|
        if b"authorization" not in headers:
 | 
						|
            LOGGER.warning("WS Request without authorization header")
 | 
						|
            self.close()
 | 
						|
 | 
						|
        token = headers[b"authorization"]
 | 
						|
        try:
 | 
						|
            token_uuid = token.decode("utf-8")
 | 
						|
            tokens = Token.filter_not_expired(
 | 
						|
                token_uuid=token_uuid, intent=TokenIntents.INTENT_API
 | 
						|
            )
 | 
						|
            if not tokens.exists():
 | 
						|
                LOGGER.warning("WS Request with invalid token")
 | 
						|
                self.close()
 | 
						|
        except ValidationError:
 | 
						|
            LOGGER.warning("WS Invalid UUID")
 | 
						|
            self.close()
 | 
						|
 | 
						|
        uuid = self.scope["url_route"]["kwargs"]["pk"]
 | 
						|
        outpost = Outpost.objects.filter(pk=uuid)
 | 
						|
        if not outpost.exists():
 | 
						|
            self.close()
 | 
						|
            return
 | 
						|
        self.accept()
 | 
						|
        self.outpost = outpost.first()
 | 
						|
        self.outpost.channels.append(self.channel_name)
 | 
						|
        LOGGER.debug("added channel to outpost", channel_name=self.channel_name)
 | 
						|
        self.outpost.save()
 | 
						|
 | 
						|
    # pylint: disable=unused-argument
 | 
						|
    def disconnect(self, close_code):
 | 
						|
        self.outpost.channels.remove(self.channel_name)
 | 
						|
        self.outpost.save()
 | 
						|
        LOGGER.debug("removed channel from outpost", channel_name=self.channel_name)
 | 
						|
 | 
						|
    def receive_json(self, content: Data):
 | 
						|
        msg = from_dict(WebsocketMessage, content)
 | 
						|
        if msg.instruction == WebsocketMessageInstruction.HELLO:
 | 
						|
            cache.set(self.outpost.health_cache_key, time(), timeout=60)
 | 
						|
        elif msg.instruction == WebsocketMessageInstruction.ACK:
 | 
						|
            return
 | 
						|
 | 
						|
        response = WebsocketMessage(instruction=WebsocketMessageInstruction.ACK)
 | 
						|
        self.send_json(asdict(response))
 | 
						|
 | 
						|
    # pylint: disable=unused-argument
 | 
						|
    def event_update(self, event):
 | 
						|
        """Event handler which is called by post_save signals"""
 | 
						|
        self.send_json(
 | 
						|
            asdict(
 | 
						|
                WebsocketMessage(instruction=WebsocketMessageInstruction.TRIGGER_UPDATE)
 | 
						|
            )
 | 
						|
        )
 |