This repo has the preconfigured WORKSPACE and git submodules to get you started on using grpc with bazel. To try this repo:
git clone https://github.com/makdharma/empty_grpc_bazel_project test
cd test
git submodule update --init
bazel build //examples/cpp/helloworld:*
This will build the greeter_client and greeter_server exacutables in bazel-bin/examples/cpp/helloworld subdirectory.