Google Drive API - Python Integration Watching A Folder

Question

I am trying to watch for changes in a Google drive folder. I have attempted to subscribe to changes to the folder and I get a response back.

My code for subscribing:

    while True:
        body = {
            "id": str(uuid4()),
            "type": "web_hook",
            "address": WEBSITE
        }
        return drive.files().watch(fileId=file_id, body=body).execute()

I get a response back saying the subscription has been accepted. Then my code for the action when there is a change:

return flask.redirect(flask.url_for('parse_doc'))

The parse_doc parses a file and uploads it to another Google Drive folder. I have then tried to upload a new file to the "watched" folder. Despite getting a yes for the subscription, the parse_doc function does not appear to ever be called.

Am I missing something? Anytime there is a change in my "watched" folder (like an upload), shouldn't Google be hitting my endpoint and the function should be called? Thanks for all of your help!

Answer 1

I can reproduce it, but I think that parse_doc is never been called because the watcher does not follow your URL redirection: a 200 response code is expected, instead, a 301 redirection is received.

If you check the documentation for push notifications on Drive it looks like this redirection is certainly the source of your problems:

Responding to notifications:

To indicate success, you can return any of the following status codes: 200, 201, 202, 204, or 102. If your service returns 500, 502, 503, or 504, the Drive API will retry with exponential backoff.

Every other return status code is considered to be a message failure and the Drive API will not retry this particular notification.

Source: https://developers.google.com/drive/api/v3/push