Grpc bazel build support (#273)

* WORKSPACE and BUILD for bazel support

* added google/protobuf BUILD file and protos

* more cleanup

* added bazel support to readme

* removed local copy of .bzl files

Using the grpc's bzl files
Cleaned up WORKSPACE
Formated BUILD files

* removed local copy of google/protobuf

Modified grpc skylark files to use protobuf submodule's
copies of the well known protos.

.gitmodules

@@ -0,0 +1,12 @@
+[submodule "third_party/protobuf"]
+	path = third_party/protobuf
+	url = https://github.com/google/protobuf
+[submodule "third_party/zlib"]
+	path = third_party/zlib
+	url = https://github.com/makdharma/zlib
+[submodule "third_party/boringssl-with-bazel"]
+	path = third_party/boringssl-with-bazel
+	url = https://boringssl.googlesource.com/boringssl
+[submodule "third_party/nanopb"]
+	path = third_party/nanopb
+	url = https://github.com/nanopb/nanopb

BUILD

@@ -0,0 +1 @@
+# empty BUILD file

README.md

@@ -67,6 +67,11 @@ entire repository. It is not for generating linkable client library
 for a specific API. Please see other repositories under
 https://github.com/googleapis for generating linkable client libraries.
 
+### Using bazel with gRPC
+Bazel build now works for a subset of the repository. You can use build
+targets from this repo as dependency into your grpc code. For example,
+this works:  ```bazel build //google/monitoring/v3:metric_service```
+
 ### Go gRPC Source Code
 It is difficult to generate Go gRPC source code from this repository,
 since Go has different directory structure.

WORKSPACE

@@ -0,0 +1,73 @@
+# nanopb
+bind(
+    name = "nanopb",
+    actual = "//third_party/nanopb",
+)
+
+# Boringssl
+bind(
+    name = "libssl",
+    actual = "@submodule_boringssl//:ssl",
+)
+
+new_local_repository(
+    name = "submodule_boringssl",
+    build_file = "third_party/boringssl-with-bazel/BUILD",
+    path = "third_party/boringssl-with-bazel",
+)
+
+# Zlib
+bind(
+    name = "zlib",
+    actual = "@submodule_zlib//:z",
+)
+
+local_repository(
+    name = "submodule_zlib",
+    path = "third_party/zlib",
+)
+
+# Protobuf
+bind(
+    name = "protobuf",
+    actual = "@submodule_protobuf//:protobuf",
+)
+
+bind(
+    name = "protobuf_clib",
+    actual = "@submodule_protobuf//:protoc_lib",
+)
+
+bind(
+    name = "protocol_compiler",
+    actual = "@submodule_protobuf//:protoc",
+)
+
+new_local_repository(
+    name = "submodule_protobuf",
+    build_file = "third_party/protobuf/BUILD",
+    path = "third_party/protobuf",
+)
+
+# grpc
+bind(
+    name = "grpc++",
+    actual = "@submodule_grpc//:grpc++",
+)
+
+bind(
+    name = "grpc++_codegen_proto",
+    actual = "@submodule_grpc//:grpc++_codegen_proto",
+)
+
+bind(
+    name = "grpc_cpp_plugin",
+    actual = "@submodule_grpc//:grpc_cpp_plugin",
+)
+
+git_repository(
+    name = "submodule_grpc",
+    remote = "https://github.com/grpc/grpc",
+    # TODO(makdharma): replace with version when bazel file fix is released
+    commit = "eb064ec7b81b60c5e1eb47d6124d0c05056b3097",
+)

google/api/BUILD

@@ -0,0 +1,58 @@
+
+package(default_visibility = ["//visibility:public"])
+
+load("@submodule_grpc//bazel:grpc_build_system.bzl", "grpc_proto_library")
+
+grpc_proto_library(
+      name = "http",
+      srcs = [
+          "http.proto",
+      ],
+      use_external = True,
+)
+
+grpc_proto_library(
+    name = "label",
+    srcs = [
+        "label.proto",
+    ],
+    use_external = True,
+)
+
+grpc_proto_library(
+    name = "distribution",
+    srcs = ["distribution.proto"],
+    deps = [
+      ":annotations",
+    ],
+    well_known_protos = "@submodule_protobuf//:well_known_protos",
+    use_external = True,
+)
+
+grpc_proto_library(
+    name = "metric",
+    srcs = ["metric.proto"],
+    deps = [
+      "//google/api:label",
+    ],
+    use_external = True,
+)
+
+grpc_proto_library(
+    name = "annotations",
+    srcs = ["annotations.proto"],
+    deps = [
+      ":http",
+    ],
+    well_known_protos = "@submodule_protobuf//:well_known_protos",
+    use_external = True,
+)
+
+grpc_proto_library(
+    name = "monitored_resource",
+    srcs = ["monitored_resource.proto"],
+    deps = [
+      ":label",
+    ],
+    use_external = True,
+)

google/monitoring/v3/BUILD

@@ -0,0 +1,42 @@
+
+package(default_visibility = ["//visibility:public"])
+
+load("@submodule_grpc//bazel:grpc_build_system.bzl", "grpc_proto_library")
+
+grpc_proto_library(name = "metric",
+    srcs = ["metric.proto"],
+    deps = [
+      "//google/api:metric",
+      "//google/api:monitored_resource",
+      ":common",
+    ],
+    well_known_protos = "@submodule_protobuf//:well_known_protos",
+    use_external = True,
+)
+
+grpc_proto_library(
+    name = "common",
+    srcs = ["common.proto"],
+    deps = [
+      "//google/api:distribution",
+      "//google/api:annotations",
+    ],
+    well_known_protos = "@submodule_protobuf//:well_known_protos",
+    use_external = True,
+)
+
+grpc_proto_library(
+    name = "metric_service",
+    srcs = ["metric_service.proto"],
+    deps = [
+      "//google/api:annotations",
+      "//google/api:metric",
+      "//google/api:monitored_resource",
+      "//google/api:label",
+      "//google/rpc:status",
+      ":common",
+      ":metric",
+    ],
+    well_known_protos = "@submodule_protobuf//:well_known_protos",
+    use_external = True,
+)

google/rpc/BUILD

@@ -0,0 +1,11 @@
+
+package(default_visibility = ["//visibility:public"])
+
+load("@submodule_grpc//bazel:grpc_build_system.bzl", "grpc_proto_library")
+
+grpc_proto_library(
+    name = "status",
+    srcs = ["status.proto"],
+    well_known_protos = "@submodule_protobuf//:well_known_protos",
+    use_external = True,
+)

third_party/boringssl-with-bazel

@@ -0,0 +1 @@
+Subproject commit 886e7d75368e3f4fab3f4d0d3584e4abfc557755

third_party/nanopb

@@ -0,0 +1 @@
+Subproject commit ac6405b4b8c7b3f449bd19bc3f8b84e6bc9fff77

third_party/protobuf

@@ -0,0 +1 @@
+Subproject commit 593e917c176b5bc5aafa57bf9f6030d749d91cd5

third_party/zlib

@@ -0,0 +1 @@
+Subproject commit 8003d572d7a41438a37e58af14302c2c5928cdd5