Setting up a subscriber to changes in a Google folder

gdrive_service.py

# python 3.7.4

import os
import json
import datetime  # for the expiration property: a date string to epoch millisec
import uuid  # for the id property

from apiclient import discovery
from google.oauth2 import service_account

try:
    ep = (
        lambda yr, mo, dd, hh, mm: int(
            datetime.datetime(yr, mo, dd, hh, mm).timestamp()
        )
        * 1000
    )
    API = "drive"
    API_VERSION = "v3" 
    scopes = [
        "https://www.googleapis.com/auth/drive",
        "https://www.googleapis.com/auth/drive.file",
    ]
    with open("client_servacc.json", "r") as read_file:
        serv_acct_info = json.load(read_file)

    # this needs to change to get credentials from a string object instead of a file 
    # i.e. json.loads of a string from AWS SSM
    # https://google-auth.readthedocs.io/en/latest/reference/google.oauth2.service_account.html

    credentials = service_account.Credentials.from_service_account_info(
        serv_acct_info, scopes=scopes
    )
    drive_service = discovery.build(API, API_VERSION, credentials=credentials)

    # more to put in SSM
    url_webhook = os.environ.get('GDRIVE_WEBHOOK_URL')
    gfolder_id = os.environ.get('GDRIVE_FOLDER_ID')
    if url_webhook and gfolder_id:
        pass
    else:
        raise KeyError


    # request body; note expiration ep is based on local time
    data = {
        "id": str(uuid.uuid4()),
        "expiration": ep(2019, 10, 17, 8, 53),   
        "address": url_webhook,
        "type": "web_hook"   
    }

    response = drive_service.files().watch(fileId=gfolder_id, body=data).execute()
    print(response)

    # sample successful request response
    # https://developers.google.com/drive/api/v3/reference/files/watch?authuser=0#response_1

except OSError as e:
    print(e)