Files
smsbot/smsbot/webhook_handler.py
2022-06-09 12:12:32 +01:00

99 lines
3.4 KiB
Python

import os
from functools import wraps
from flask import Flask, abort, current_app, request
from prometheus_client import Counter, Summary, make_wsgi_app
from twilio.request_validator import RequestValidator
from waitress import serve
from werkzeug.middleware.dispatcher import DispatcherMiddleware
from smsbot.utils import get_smsbot_version
REQUEST_TIME = Summary('webhook_request_processing_seconds', 'Time spent processing request')
MESSAGE_COUNT = Counter('webhook_message_count', 'Total number of messages processed')
CALL_COUNT = Counter('webhook_call_count', 'Total number of calls processed')
def validate_twilio_request(func):
"""Validates that incoming requests genuinely originated from Twilio"""
@wraps(func)
def decorated_function(*args, **kwargs): # noqa: WPS430
# Create an instance of the RequestValidator class
twilio_token = os.environ.get('SMSBOT_TWILIO_AUTH_TOKEN')
if not twilio_token:
current_app.logger.warning('Twilio request validation skipped due to SMSBOT_TWILIO_AUTH_TOKEN missing')
return func(*args, **kwargs)
validator = RequestValidator(twilio_token)
# Validate the request using its URL, POST data,
# and X-TWILIO-SIGNATURE header
request_valid = validator.validate(
request.url,
request.form,
request.headers.get('X-TWILIO-SIGNATURE', ''),
)
# Continue processing the request if it's valid, return a 403 error if
# it's not
if request_valid or current_app.debug:
return func(*args, **kwargs)
return abort(403)
return decorated_function
class TwilioWebhookHandler(object):
def __init__(self):
self.app = Flask(self.__class__.__name__)
self.app.add_url_rule('/', 'index', self.index, methods=['GET'])
self.app.add_url_rule('/health', 'health', self.health, methods=['GET'])
self.app.add_url_rule('/message', 'message', self.message, methods=['POST'])
self.app.add_url_rule('/call', 'call', self.call, methods=['POST'])
# Add prometheus wsgi middleware to route /metrics requests
self.app.wsgi_app = DispatcherMiddleware(self.app.wsgi_app, {
'/metrics': make_wsgi_app(),
})
def set_bot(self, bot): # noqa: WPS615
self.bot = bot
def index(self):
return ''
@REQUEST_TIME.time()
def health(self):
return {
'version': get_smsbot_version(),
'owner': self.bot.owner_id,
'subscribers': self.bot.subscriber_ids,
}
@REQUEST_TIME.time()
@validate_twilio_request
def message(self):
current_app.logger.info('Received SMS from {From}: {Body}'.format(**request.values.to_dict()))
message = 'From: {From}\n\n{Body}'.format(**request.values.to_dict())
self.bot.send_subscribers(message)
# Return a blank response
MESSAGE_COUNT.inc()
return '<response></response>'
@REQUEST_TIME.time()
@validate_twilio_request
def call(self):
current_app.logger.info('Received Call from {From}'.format(**request.values.to_dict()))
self.bot.send_subscribers('Received Call from {From}, rejecting.'.format(**request.values.to_dict()))
# Always reject calls
CALL_COUNT.inc()
return '<Response><Reject/></Response>'
def serve(self, host='0.0.0.0', port=80, debug=False):
serve(self.app, host=host, port=port)