Re-enable bundling (for consideration) - #1950

@daspecster Can you try running the pubsub system tests on your branch with gRPC enabled? E.g.:

$ tox -e system-tests --notest
$ GCLOUD_ENABLE_GAX .tox/system-tests/bin/python \
  system_tests/run_system_test.py --package=pubsub

LGTM once Travis passes, assuming the system tests pass for you with gRPC/GAX enabled.

I ran it with this...

GCLOUD_TESTS_PROJECT_ID=ferrous-arena GOOGLE_APPLICATION_CREDENTIALS=creds.json GCLOUD_ENABLE_GAX=True .tox/system-tests/bin/python system_tests/run_system_test.py --package=pubsub

That spew at the end is gRPC whining: harmless, but annoying for our purposes. I won't tackle #1873 until it is resolved, though.

LGTM

@bjwatson Ugh, are you saying that the only change we needed was to set is_bundling=True in the CallOptions constructor?

I think so.

@bjwatson, these are the only references to is_bundling in https://github.com/googleapis/gax-python/search?utf8=%E2%9C%93&q=is_bundling&type=Code.

I'm not sure how the discovery stuff works but, what/how would pick up on the is_bundling flag?

@daspecster The first reference is the one that does the magic: https://github.com/googleapis/gax-python/blob/75fc5bdbbad46ab1d08d30718ef1485ae211eb5b/google/gax/__init__.py#L134

It depends on bundling settings being configured for the method: https://github.com/googleapis/googleapis/blob/master/google/pubsub/v1/pubsub_gapic.yaml#L227

I'm not sure about Discovery. Are you doing anything with that? It's just generating file-length sample code right now, and not any API surfaces.

@bjwatson, thanks!

I'm not sure on the Discovery question.
@tseaver, do you know?