bigtable.client shouldn't require credentials when it is connected to the emulator

[christineoo]

maybe related to:
#184

In the local environment, when the BigTable client is connected to a BigTable Emulator credentials shouldn't be required.

Environment details

• OS type and version: macOS Big Sur v11.0.1
• Python version: 3.7.9
• pip version: 20.1.1
• google-cloud-bigtable version: 1.7.0

Steps to reproduce

  1. gcloud beta emulators bigtable start
  2. env BIGTABLE_EMULATOR_HOST=localhost:8086 python main.py

Code example

# main.py
import os

from google.cloud import bigtable

PROJECT_ID = 'my-project'
BIGTABLE_INSTANCE = 'emulator'
TABLE_ID = 'my-table'

print(f"bigtable emulator: {os.getenv('BIGTABLE_EMULATOR_HOST')}")

def main(project_id="project-id", instance_id="instance-id",
         table_id="my-table"):
    # Create a Cloud Bigtable client.
    client = bigtable.Client(project=project_id)

    # Connect to an existing Cloud Bigtable instance.
    instance = client.instance(instance_id)

    # Open an existing table.
    table = instance.table(table_id)

    row_key = 'r1'
    row = table.read_row(row_key.encode('utf-8'))

    column_family_id = 'cf1'
    column_id = 'c1'.encode('utf-8')
    value = row.cells[column_family_id][column_id][0].value.decode('utf-8')

    print('Row key: {}\nData: {}'.format(row_key, value))


if __name__ == '__main__':
    main(PROJECT_ID, BIGTABLE_INSTANCE, TABLE_ID)

Stack trace

bigtable emulator: localhost:8086
Traceback (most recent call last):
  File "main.py", line 33, in <module>
    main(PROJECT_ID, BIGTABLE_INSTANCE, TABLE_ID)
  File "main.py", line 14, in main
    client = bigtable.Client(project=project_id)
  File "/Users/xx/Documents/gcloud-playground/bigtable__temp/env/lib/python3.7/site-packages/google/cloud/bigtable/client.py", line 192, in __init__
    client_options=client_options,
  File "/Users/xx/Documents/gcloud-playground/bigtable__temp/env/lib/python3.7/site-packages/google/cloud/client.py", line 278, in __init__
    Client.__init__(self, credentials=credentials, client_options=client_options, _http=_http)
  File "/Users/xx/Documents/gcloud-playground/bigtable__temp/env/lib/python3.7/site-packages/google/cloud/client.py", line 153, in __init__
    credentials, _ = google.auth.default(scopes=scopes)
  File "/Users/xx/Documents/gcloud-playground/bigtable__temp/env/lib/python3.7/site-packages/google/auth/_default.py", line 483, in default
    raise exceptions.DefaultCredentialsError(_HELP_MESSAGE)
google.auth.exceptions.DefaultCredentialsError: Could not automatically determine credentials. Please set GOOGLE_APPLICATION_CREDENTIALS or explicitly create credentials and re-run the application. For more information, please see https://cloud.google.com/docs/authentication/getting-started

Please help to look into this issue 🙏 Thanks!

[torin-givemomentum]

I'm still encountering this error on version 2.3.3. Are you sure this is fixed?

Environment:
OS type and version: Debian GNU/Linux 10 (buster) (WSL2)
Python version: 3.9.6
google-cloud-bigtable version: 2.3.3

Steps to reproduce
Same commands and code as reported by christineoo above.

Stacktrace

bigtable emulator: localhost:8530
Traceback (most recent call last):
  File "/tmp/main.py", line 33, in <module>
    main(PROJECT_ID, BIGTABLE_INSTANCE, TABLE_ID)
  File "/tmp/main.py", line 14, in main
    client = bigtable.Client(project=project_id)
  File "/home/torin/.cache/pypoetry/virtualenvs/momentum-backend-_rXW-4N5-py3.9/lib/python3.9/site-packages/google/cloud/bigtable/client.py", line 184, in __init__
    super(Client, self).__init__(
  File "/home/torin/.cache/pypoetry/virtualenvs/momentum-backend-_rXW-4N5-py3.9/lib/python3.9/site-packages/google/cloud/client.py", line 317, in __init__
    Client.__init__(
  File "/home/torin/.cache/pypoetry/virtualenvs/momentum-backend-_rXW-4N5-py3.9/lib/python3.9/site-packages/google/cloud/client.py", line 176, in __init__
    credentials, _ = google.auth.default(scopes=scopes)
  File "/home/torin/.cache/pypoetry/virtualenvs/momentum-backend-_rXW-4N5-py3.9/lib/python3.9/site-packages/google/auth/_default.py", line 488, in default
    raise exceptions.DefaultCredentialsError(_HELP_MESSAGE)
google.auth.exceptions.DefaultCredentialsError: Could not automatically determine credentials. Please set GOOGLE_APPLICATION_CREDENTIALS or explicitly create credentials and re-run the application. For more information, please see https://cloud.google.com/docs/authentication/getting-started