channel_output_webhook.py

"""
Output channel that sends to webhooks.
"""
from zope.interface import implementer
from twisted.web.iweb import IBodyProducer
from twisted.internet.defer import succeed
from twisted.logger import Logger
log = Logger()
from twisted.internet import reactor
from twisted.web.client import Agent
from twisted.web.http_headers import Headers
import simplejson

from channel import OutputChannel
from constants import OUTPUT_CHANNEL_WEBHOOK

@implementer(IBodyProducer)
class BytesProducer:
    def __init__(self, body):
        self.body = body
        self.length = len(body)

    def startProducing(self, consumer):
        consumer.write(self.body)
        return succeed(None)

    def pauseProducing(self):
        pass

    def stopProducing(self):
        pass

class WebhookOutputChannel(OutputChannel):
    CHANNEL = OUTPUT_CHANNEL_WEBHOOK


    def do_send_alert(self, input_channel=None, canarydrop=None, **kwargs):

        slack = "https://hooks.slack.com"

        try:
            if (slack in canarydrop['alert_webhook_url']):
                payload = input_channel.format_slack_canaryalert(
                                            canarydrop=canarydrop,
                                            **kwargs)
            else:
                payload = input_channel.format_webhook_canaryalert(
                                            canarydrop=canarydrop,
                                            **kwargs)

            self.generic_webhook_send(simplejson.dumps(payload), canarydrop)
        except Exception as e:
            log.error(e)

    def generic_webhook_send(self, payload=None, canarydrop=None):

        def handle_response(response):
            if response.code != 200:
                log.error("Failed sending request to webhook {url} with code {error}".format(url=canarydrop['alert_webhook_url'],error=response.code))
            else:
                log.info('Webhook sent to {url}'.format(url=canarydrop['alert_webhook_url']))

        def handle_error(result):
            log.error("Failed sending request to webhook {url} with error {error}".format(url=canarydrop['alert_webhook_url'],error=result))

        agent = Agent(reactor)
        body = BytesProducer(payload)
        d = agent.request("POST", canarydrop['alert_webhook_url'], Headers({'content-type': ['application/json']}), body)
        d.addCallback(handle_response)
        d.addErrback(handle_error)