[CT-49] [Bug] dbt deps does not handle/retry on a malformed response from hub

[barberscott]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

If in the process of running dbt deps dbt receives a malformed response from hub.getdbt.com deps will fail:

Traceback (most recent call last):
  File "/usr/src/app/sinter/clients/dbt.py", line 1200, in call
    dbt_main.handle(command + extra_args)
  File "/usr/local/lib/python3.8/dist-packages/dbt/main.py", line 152, in handle
    res, success = handle_and_check(args)
  File "/usr/local/lib/python3.8/dist-packages/dbt/main.py", line 192, in handle_and_check
    task, res = run_from_args(parsed)
  File "/usr/local/lib/python3.8/dist-packages/dbt/main.py", line 246, in run_from_args
    results = task.run()
  File "/usr/local/lib/python3.8/dist-packages/dbt/task/deps.py", line 56, in run
    final_deps = resolve_packages(packages, self.config)
  File "/usr/local/lib/python3.8/dist-packages/dbt/deps/resolver.py", line 135, in resolve_packages
    target = final[package].resolved().fetch_metadata(config, renderer)
  File "/usr/local/lib/python3.8/dist-packages/dbt/deps/registry.py", line 121, in resolved
    self._check_in_index()
  File "/usr/local/lib/python3.8/dist-packages/dbt/deps/registry.py", line 92, in _check_in_index
    if self.package not in index:
TypeError: argument of type 'NoneType' is not iterable

while attempting to parse the JSON response which, presumably, is bad.

Expected Behavior

• Log the bad JSON so that we know what hub sent
• Retry similar to how retry happens for failures to connect and for empty responses

Steps To Reproduce

No response

Relevant log output

No response

Environment

No response

What database are you using dbt with?

No response

Additional Context

No response

[emmyoop]

@barberscott thanks again for the detailed issue! This is a result of a big of a bug associated with our retry logic.

We should be checking here if resp.json() is None not just the resp object.

dbt-core/core/dbt/clients/registry.py

Lines 36 to 39 in 7798f93

	if resp is None:
	raise requests.exceptions.ContentDecodingError(
	'Request error: The response is None', response=resp
	)

If it is None we should retry.

This issue is part of our next release (1.0.2) and I'm actively working on it! Similar to #4579 I'm going to need to think a bit more on what, if anything, should be logged in this case. Possibly the entire response? Once I fix the logic to fall into the ContentDecodingError, we will be logging the entire response!

[leahwicz]

Backport here: #4649