Update Python interop tests to use google-auth package

The oauth2client test dependency is still needed as it used by
the beta API unit tests.

src/python/grpcio_tests/setup.py

@@ -56,7 +56,8 @@ INSTALL_REQUIRES = (
     'grpcio>={version}'.format(version=grpc_version.VERSION),
     'grpcio-tools>={version}'.format(version=grpc_version.VERSION),
     'grpcio-health-checking>={version}'.format(version=grpc_version.VERSION),
-    'oauth2client>=1.4.7', 'protobuf>=3.3.0', 'six>=1.10',)
+    'oauth2client>=1.4.7', 'protobuf>=3.3.0', 'six>=1.10', 'google-auth>=1.0.0',
+    'requests>=2.14.2')
 
 COMMAND_CLASS = {
     # Run `preprocess` *before* doing any packaging!

src/python/grpcio_tests/tests/interop/client.py

@@ -29,10 +29,11 @@
 """The Python implementation of the GRPC interoperability test client."""
 
 import argparse
-from oauth2client import client as oauth2client_client
+import os
 
+from google import auth as google_auth
+from google.auth import jwt as google_auth_jwt
 import grpc
-from grpc.beta import implementations
 from src.proto.grpc.testing import test_pb2
 
 from tests.interop import methods
@@ -84,25 +85,24 @@ def _application_default_credentials():
 def _stub(args):
     target = '{}:{}'.format(args.server_host, args.server_port)
     if args.test_case == 'oauth2_auth_token':
-        google_credentials = _application_default_credentials()
-        scoped_credentials = google_credentials.create_scoped(
-            [args.oauth_scope])
-        access_token = scoped_credentials.get_access_token().access_token
-        call_credentials = grpc.access_token_call_credentials(access_token)
+        google_credentials, unused_project_id = google_auth.default(
+            scopes=[args.oauth_scope])
+        google_credentials.refresh(google_auth.transport.requests.Request())
+        call_credentials = grpc.access_token_call_credentials(
+            google_credentials.token)
     elif args.test_case == 'compute_engine_creds':
-        google_credentials = _application_default_credentials()
-        scoped_credentials = google_credentials.create_scoped(
-            [args.oauth_scope])
-        # TODO(https://github.com/grpc/grpc/issues/6799): Eliminate this last
-        # remaining use of the Beta API.
-        call_credentials = implementations.google_call_credentials(
-            scoped_credentials)
+        google_credentials, unused_project_id = google_auth.default(
+            scopes=[args.oauth_scope])
+        call_credentials = grpc.metadata_call_credentials(
+            google_auth.transport.grpc.AuthMetadataPlugin(
+                credentials=google_credentials,
+                request=google_auth.transport.requests.Request()))
     elif args.test_case == 'jwt_token_creds':
-        google_credentials = _application_default_credentials()
-        # TODO(https://github.com/grpc/grpc/issues/6799): Eliminate this last
-        # remaining use of the Beta API.
-        call_credentials = implementations.google_call_credentials(
-            google_credentials)
+        google_credentials = google_auth_jwt.OnDemandCredentials.from_service_account_file(
+            os.environ[google_auth.environment_vars.CREDENTIALS])
+        call_credentials = grpc.metadata_call_credentials(
+            google_auth.transport.grpc.AuthMetadataPlugin(
+                credentials=google_credentials, request=None))
     else:
         call_credentials = None
     if args.use_tls:

src/python/grpcio_tests/tests/interop/methods.py

@@ -33,8 +33,10 @@ import json
 import os
 import threading
 
-from oauth2client import client as oauth2client_client
-
+from google import auth as google_auth
+from google.auth import environment_vars as google_auth_environment_vars
+from google.auth.transport import grpc as google_auth_transport_grpc
+from google.auth.transport import requests as google_auth_transport_requests
 import grpc
 from grpc.beta import implementations
 
@@ -401,8 +403,7 @@ def _compute_engine_creds(stub, args):
 
 
 def _oauth2_auth_token(stub, args):
-    json_key_filename = os.environ[
-        oauth2client_client.GOOGLE_APPLICATION_CREDENTIALS]
+    json_key_filename = os.environ[google_auth_environment_vars.CREDENTIALS]
     wanted_email = json.load(open(json_key_filename, 'rb'))['client_email']
     response = _large_unary_common_behavior(stub, True, True, None)
     if wanted_email != response.username:
@@ -414,8 +415,7 @@ def _oauth2_auth_token(stub, args):
 
 
 def _jwt_token_creds(stub, args):
-    json_key_filename = os.environ[
-        oauth2client_client.GOOGLE_APPLICATION_CREDENTIALS]
+    json_key_filename = os.environ[google_auth_environment_vars.CREDENTIALS]
     wanted_email = json.load(open(json_key_filename, 'rb'))['client_email']
     response = _large_unary_common_behavior(stub, True, False, None)
     if wanted_email != response.username:
@@ -424,15 +424,14 @@ def _jwt_token_creds(stub, args):
 
 
 def _per_rpc_creds(stub, args):
-    json_key_filename = os.environ[
-        oauth2client_client.GOOGLE_APPLICATION_CREDENTIALS]
+    json_key_filename = os.environ[google_auth_environment_vars.CREDENTIALS]
     wanted_email = json.load(open(json_key_filename, 'rb'))['client_email']
-    credentials = oauth2client_client.GoogleCredentials.get_application_default()
-    scoped_credentials = credentials.create_scoped([args.oauth_scope])
-    # TODO(https://github.com/grpc/grpc/issues/6799): Eliminate this last
-    # remaining use of the Beta API.
-    call_credentials = implementations.google_call_credentials(
-        scoped_credentials)
+    google_credentials, unused_project_id = google_auth.default(
+        scopes=[args.oauth_scope])
+    call_credentials = grpc.metadata_call_credentials(
+        google_auth_transport_grpc.AuthMetadataPlugin(
+            credentials=google_credentials,
+            request=google_auth_transport_requests.Request()))
     response = _large_unary_common_behavior(stub, True, False, call_credentials)
     if wanted_email != response.username:
         raise ValueError('expected username %s, got %s' %

tools/run_tests/helper_scripts/build_python.sh

@@ -187,7 +187,8 @@ $VENV_PYTHON $ROOT/src/python/grpcio_reflection/setup.py build_package_protos
 pip_install_dir $ROOT/src/python/grpcio_reflection
 
 # Build/install tests
-$VENV_PYTHON -m pip install coverage oauth2client
+$VENV_PYTHON -m pip install coverage==4.4 oauth2client==4.1.0 \
+                            google-auth==1.0.0 requests==2.14.2
 $VENV_PYTHON $ROOT/src/python/grpcio_tests/setup.py preprocess
 $VENV_PYTHON $ROOT/src/python/grpcio_tests/setup.py build_package_protos
 pip_install_dir $ROOT/src/python/grpcio_tests