Add bigtable generated files

[dhermes]

@tseaver These are generated with

https://github.com/dhermes/gcloud-python-bigtable/blob/7c88583a4f772701228c2c94c32a847670fe6a52/Makefile

I had to modify

https://github.com/dhermes/gcloud-python-bigtable/blob/7c88583a4f772701228c2c94c32a847670fe6a52/scripts/rewrite_imports.py

so that it rewrote imports as gcloud.bigtable instead of gcloud_bigtable.

---

Should I try to port the Makefile over as well? The reason I hesitate is because it requires having a valid gRPC install.

[tseaver]

I don't think there is much to review here: should we maybe be reviewing the generator first?

[dhermes]

Sure. That is contingent on whether we should add it to the repo. A Makefile is certainly not platform independent, so I hesitate a little bit. (NOTE: I want to do a similar thing with #594 but the gRPC plugin for protoc makes some imports that we can't use. I need to be less dumb using namespace packages though and maybe we could avoid import rewrites.)

[tseaver]

Should we be checking in the .proto files?

[dhermes]

Yeah good call!

[tseaver]

I think checking in the Makefile too is worthwhile: even if it is Unix/Linux/Ubuntu-dependent, it "documents" how the generated files are created, allowing users to figure out how to replicate on their own systems.

[dhermes]

I just added the .proto files. I'll bring in the Makefile too and we can discuss once it's in.

Do you want me to re-arrange the commits to make it more clear what's going in?

[tseaver]

Commit order doesn't really matter to me -- I'm going to look primarily at the Makefile and one each of the .proto and _pb2.py files. If you think it is cleaner to rebase down to a single commit, that would be fine.

[tseaver]

When the Makefile comes in, will I be able to regenerate from it (assuming protoc is on the path)?

[dhermes]

Not unless you also have the grpc_python_plugin installed. And you may need the latest and greatest version of protoc to support proto3 (was proto2 for awhile). I'm not sure about that one though.

[dhermes]

@tseaver PTAL (I added the Makefile)

[tseaver]

LGTM -- I wish we had directions (in CONTRIBUTING.rst, maybe) about the environment needed to be able to recreate the generated files.

[dhermes]

Take a look through

https://github.com/dhermes/gcloud-python-bigtable/blob/master/README.md
https://github.com/dhermes/gcloud-python-bigtable/blob/master/CONTRIBUTING.md

and let me know what you'd like to be brought over.

Unfortunately (or maybe it's fortunate?) the gRPC install story is ever-evolving so the docs will be out-of-date pretty soon.