Read JSON credentials from string instead of file

[llamafilm]

Is your feature request related to a problem? Please describe.
I'm storing the credentials.json data in an encrypted form which gets decrypted by my application on runtime. It's risky to write this back to disk in plaintext, so I'd like to login using this string in memory instead.

Describe the solution you'd like
How I authenticate now:

os.environ['GOOGLE_APPLICATION_CREDENTIALS'] = 'credentials.json'

How I'd like to authenticate:

GOOGLE_APPLICATION_CREDENTIALS = "string from variable"

Additional context
For what it's worth, there is a similar feature request for Go: googleapis/google-api-go-client#185

[parthea]

Hi @llamafilm,

There was a feature added in googleapis/google-auth-library-python#1326 to add support for google.auth.load_credentials_from_dict() to load credentials from a dictionary, however that does not change the behaviour of the environment variable GOOGLE_APPLICATION_CREDENTIALS.

See
https://github.com/googleapis/google-auth-library-python/blob/a4135a3e9620a2cbf99957858c13780b92ff707c/google/auth/_default.py#L134

If you'd like to propose a feature request to change the behaviour of GOOGLE_APPLICATION_CREDENTIALS, please file a feature request for google-auth here.

I'm going to close this issue as the handling for GOOGLE_APPLICATION_CREDENTIALS is specific to google-auth but pease feel free to open a new issue if you have additional questions.