changes to x-task-id parsing logic for responses without a json body

[sbarbett]

There's still a problem with how the connection logic handles adding the task ID.

Creating zone snapshots:   0%|                                                                                                                                                          | 0/315 [00:00<?, ?it/s]{'Access-Control-Allow-Headers': 'Origin, X-Requested-With, Content-Type, Accept, Authorization', 'Access-Control-Allow-Methods': 'POST, GET, OPTIONS, DELETE, PUT, PATCH', 'Access-Control-Allow-Origin': '*', 'Access-Control-Max-Age': '3600', 'Content-Security-Policy': "default-src 'self' https:; font-src 'self' https: data:; img-src 'self' https: data:; object-src 'none'; script-src https:; style-src 'self' https: 'unsafe-inline'", 'Date': 'Fri, 08 Nov 2024 14:06:38 GMT', 'Referrer-Policy': 'no-referrer', 'Strict-Transport-Security': 'max-age=31536000; includeSubDomains; preload', 'Vary': 'Origin, Access-Control-Request-Method, Access-Control-Request-Headers', 'X-Content-Type-Options': 'nosniff', 'X-Download-Options': 'noopen', 'X-Frame-Options': 'DENY', 'X-Permitted-Cross-Domain-Policies': 'none', 'X-Task-Id': '14b14a0e-42c3-412d-840a-126b66b2bbe7', 'X-Xss-Protection': '1 ; mode=block', 'Content-Length': '0', 'Connection': 'keep-alive'}
202
{}
Creating zone snapshots:   0%|                                                                                                                                                          | 0/315 [00:00<?, ?it/s]
Traceback (most recent call last):
  File "/Users/sbarbett/projects/udns_snapshot/./src/snapshot.py", line 270, in <module>
    main(args.username, args.password, args.token, args.refresh_token, args.restore, args.log_file, args.download, args.zones_file)
  File "/Users/sbarbett/projects/udns_snapshot/./src/snapshot.py", line 234, in main
    task = create_snapshot(client, zone)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/sbarbett/projects/udns_snapshot/./src/snapshot.py", line 116, in create_snapshot
    task = response["task_id"]
           ~~~~~~~~^^^^^^^^^^^
KeyError: 'task_id'

In the output above I'd like to highlight a couple things.

1. In the response header, there's an X-Task-Id and the status code is 202 - This indicates that the request was successful.
2. The {} indicates that the response from the client is empty, so the task_id, despite being present, was not added to the dict.
3. My code fails because it was expecting a task_id

Looking at the logic here, it's because of how the parsing of the JSON body and try...catch statement are structured.

json_body = {}
try:
  json_body = response.json()

  # if this is a background task, add the task id (or location) to the body
  if response.status_code == requests.codes.ACCEPTED:
    if 'x-task-id' in response.headers:
      json_body.update({"task_id": response.headers['x-task-id']})
    if 'location' in response.headers:
      json_body.update({"location": response.headers['location']})

except requests.exceptions.JSONDecodeError:
  json_body = {}

The response from this API contains no body, so json_body = response.json() is going to fail, but the if statement is nested inside this try...catch. Let's see what happens if I print the exception message.

except requests.exceptions.JSONDecodeError as e:
  print(e)
  json_body = {}

I get the following message.

Expecting value: line 1 column 1 (char 0)

This supports my suspicion, that it can't parse the empty value and is therefore raising an exception and not making it to the conditional statements.

I think the parsing of the hypothetical json body using a try...catch block and conditional statements should happen independently of each other to avoid this issue.