AWS SES notifications (and process_recipient fix for previous PR)

[anandvenkatanarayanan]

This Pull request adds support for processing AWS SES notifications. To enable processing, the following steps are required:

1. Create a hook API for parsing notifications (See example below)
2. Add the hook API as a SNS end point (This has to be done in the AWS production terraform code once we update the hook location)

import json

from flask import Flask, request, Response

from aws_ses import Validator, ValidatorException, Type, SesEvent


class ValidatorApp(Flask):

    def __init__(self, import_name):
        super().__init__(import_name)
        topic_arn = TOPIC_ARN # Must be read from a CONFIG VARIABLE
        self.ses_validator = Validator(topics=[topic_arn])


app = ValidatorApp(__name__)


@app.route('/ses-event-processor', methods=["POST"])
def main():
    # Try to decode the JSON
    try:
        message = json.loads(request.data)
    except json.decoder.JSONDecodeError:
        error_msg = 'Request body is not in json format.'
        return Response(error_msg, status=400)

    # Validate message
    try:
        app.ses_validator.check(message)
    except ValidatorException as ex:
        return Response(ex.args, status=400)

    # Message Type
    m_type = message.get('Type')

    # Subscription confirmation
    if m_type == Type.SubscriptionConfirmation.value:
        resp = requests.get(message.get('SubscribeURL'))
        if resp.status_code != 200:
            return Response('Request to SubscribeURL failed. Unable to confirm subscription.', status=500)
        return Response('Subscription is successfully confirmed.', status=200)

    # unsubscribe confirmation.
    if m_type == Type.UnsubscribeConfirmation.value:
        resp = requests.get(message.get('UnsubscribeURL'))
        if resp.status_code != 200:
            return Response('Request to UnsubscribeURL failed. Unable to unsubscribe.', status=500)
        return Response('Successfully unsubscribed.', status=200)

    # This is a Notification and we need to process it.
    if m_type == Type.Notification.value:
        ses_event: SesEvent = SesEvent.from_json(message.get('Message'))
        # Add Processing code for ses_event
        return Response(f'Notification Processed for event {ses_event.eventType}', status=200)


if __name__ == '__main__':
    app.run()

[jace]

Cleaned this up and the tests are passing, but the Send/Delivery event looks suspicious. Is that how it's supposed to work?