Spanner ignores provided credentials when executing a query.

[lukesneeringer]

(This bug is re-posted from an e-mail I received yesterday.)

---

We are using python spanner client libraries, and I have a credentials issue in executing a sql query. Seems like executing a sql ignores the provided credentials to the client and just try to use the default credentials.

The code looks like:

spanner_client = spanner.Client(credentials=credentials, project=project_id)
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
database.execute_sql(stmt)

Debugging the code for a bit, I found out that eventually the code will try to create a session and it will try to get the spanner API client. When this object created, credentials is not passed and hence it's None, and hence the SpannerClient is trying to get the default credentials and fails in my case because I do not have default creds.

[tseaver]

Parallels #3070, but in the database module.

[tseaver]

Hmm, weird. The following patch passes through credentials from the client to the SpannerClientt constructor:

diff --git a/spanner/google/cloud/spanner/database.py b/spanner/google/cloud/spanner/database.py
index 9b838bf..82d8a52 100644
--- a/spanner/google/cloud/spanner/database.py
+++ b/spanner/google/cloud/spanner/database.py
@@ -155,7 +155,10 @@ class Database(object):
         """Helper for session-related API calls."""
         if self._spanner_api is None:
             self._spanner_api = SpannerClient(
-                lib_name='gccl', lib_version=__version__)
+                lib_name='gccl',
+                lib_version=__version__,
+                credentials=self._instance._client.credentials,
+            )
         return self._spanner_api
 
     def __eq__(self, other):

but when I run the system tests with that patch, they fail with:

n to_call(*args)
  File "/home/tseaver/projects/agendaless/Google/src/google-cloud-python/spanner/.nox/sys-3-6/lib/python3.6/site-packages/google/gax/retry.py", line 68, in inner
    return a_func(*updated_args, **kwargs)
  File "/home/tseaver/projects/agendaless/Google/src/google-cloud-python/spanner/.nox/sys-3-6/lib/python3.6/site-packages/grpc/_channel.py", line 507, in __call__
    return _end_unary_response_blocking(state, call, False, deadline)
  File "/home/tseaver/projects/agendaless/Google/src/google-cloud-python/spanner/.nox/sys-3-6/lib/python3.6/site-packages/grpc/_channel.py", line 455, in _end_unary_response_blocking
    raise _Rendezvous(state, None, None, deadline)
grpc._channel._Rendezvous: <_Rendezvous of RPC that terminated with (StatusCode.PERMISSION_DENIED, Request had insufficient authentication scopes.)>

I've checked, and the scopes on the credentials should work (arguably they are too broad):

(Pdb) pp self._instance._client.credentials._scopes
('https://www.googleapis.com/auth/spanner.admin',)

@dhermes, @jonparrott Does that ring any bell?

[theacodes]

Yeah that doesn't seem right. @vkedia, do you know why the spanner.admin scope wouldn't work?

[mbassiouny]

I guess this has to be https://www.googleapis.com/auth/spanner.data. Admin is for administrative actions (Create instance/database).

[mbassiouny]

Thanks for the quick fix. In what version this will be in, and also what is the timeline for the release?

[lukesneeringer]

@mbassiouny Our intent is to do a release today. No reason we can not get this in.

[mbassiouny]

@lukesneeringer Thanks!

[dhermes]

@lukesneeringer It must be merged first 😀