Intermittent DefaultCredentialsError on GCE #211
Description
Original issue: googleapis/google-cloud-python#4358
After successful use of credentials, _ = google.auth.default(), an application crashes when credentials cannot be detected:
...
File "/usr/local/lib/python2.7/dist-packages/google/cloud/client.py", line 212, in __init__
Client.__init__(self, credentials=credentials, _http=_http)
File "/usr/local/lib/python2.7/dist-packages/google/cloud/client.py", line 125, in __init__
credentials, _ = google.auth.default()
File "/usr/local/lib/python2.7/dist-packages/google/auth/_default.py", line 286, in default
raise exceptions.DefaultCredentialsError(_HELP_MESSAGE)
DefaultCredentialsError: Could not automatically determine credentials. Please set GOOGLE_APPLICATION_CREDENTIALS or
explicitly create credential and re-run the application. For more
information, please see
https://developers.google.com/accounts/docs/application-default-credentials./cc @dmho418