Example of a Hoverfly middleware script which creates a response based on csv lookup

middleware.py

#!/usr/local/bin/python3

import sys, csv
import json
import logging

logging.basicConfig(filename='middleware.log', level=logging.DEBUG)
logging.debug('middleware called')

tokens = {}
# CSV file containing our user ids and tokens
with open('auth_test.csv') as csvfile:
    reader = csv.DictReader(csvfile)
    for row in reader: tokens[row['token']] = row['uid']

def main():

    data = sys.stdin.readlines()
    # this is a json string in one line so we are interested in that one line
    payload = data[0]
    payload_dict = json.loads(payload)
    uid = None

    if "request" in payload_dict and "body" in payload_dict["request"]:


        request_body = payload_dict["request"]["body"]
        if request_body and request_body[0] in ["[", "{"]:
            json_body = json.loads(request_body)
            token = json_body['token']
            uid = tokens.get(token)

    if "response" in payload_dict and "body" in payload_dict["response"]:
        if uid:
            payload_dict["response"] = {
                    "status": 200,
                    "body": "{\"valid\":true, \"userId\":\"%s\"}" % uid,
                    "encodedBody": False,
                "headers": {
                    "Content-Type": [
                        "application/json"
                    ],
                    "Transfer-Encoding": [
                        "chunked"
                    ]
                },
                "templated": False
            }
            logging.debug("New Response Body: " + payload_dict['response']['body'])
    print(json.dumps(payload_dict))


if __name__ == "__main__":
    main()