Add py_proto_library() rules for envoy/api. (#194)

src/WORKSPACE

@@ -75,3 +75,16 @@ git_repository(
 load("@io_bazel_rules_go//go:def.bzl", "go_rules_dependencies", "go_register_toolchains")
 go_rules_dependencies()
 go_register_toolchains()
+
+# py rules related
+http_archive(
+    name = "six_archive",
+    build_file = "@com_google_protobuf//:six.BUILD",
+    sha256 = "105f8d68616f8248e24bf0e9372ef04d3cc10104f1980f54d57b2ce73a5ad56a",
+    urls = ["https://pypi.python.org/packages/source/s/six/six-1.10.0.tar.gz#md5=34eed507548117b2ab523ab14b2f8b55"],
+)
+
+bind(
+    name = "six",
+    actual = "@six_archive//:six",
+)

src/opencensus/proto/resource/v1/BUILD.bazel

@@ -15,6 +15,7 @@
 package(default_visibility = ["//visibility:public"])
 
 load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")
+load("@com_google_protobuf//:protobuf.bzl", "py_proto_library")
 
 proto_library(
     name = "resource_proto",
@@ -36,3 +37,8 @@ go_proto_library(
     proto = ":resource_proto",
     importpath = "github.com/census-instrumentation/opencensus-proto/gen-go/resource/v1",
 )
+
+py_proto_library(
+    name = "resource_proto_py",
+    srcs = ["resource.proto"],
+)

src/opencensus/proto/trace/v1/BUILD.bazel

@@ -16,6 +16,7 @@ package(default_visibility = ["//visibility:public"])
 
 load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")
 load("@io_bazel_rules_go//go:def.bzl", "go_library")
+load("@com_google_protobuf//:protobuf.bzl", "py_proto_library")
 
 proto_library(
     name = "trace_proto",
@@ -69,6 +70,20 @@ go_proto_library(
     importpath = "github.com/census-instrumentation/opencensus-proto/gen-go/trace/v1",
 )
 
+py_proto_library(
+    name = "trace_proto_py",
+    srcs = ["trace.proto"],
+    deps = [
+        "@com_google_protobuf//:protobuf_python",
+        "//opencensus/proto/resource/v1:resource_proto_py",
+    ],
+)
+
+py_proto_library(
+    name = "trace_config_proto_py",
+    srcs = ["trace_config.proto"],
+)
+
 # This a workaround because `trace_proto_go` and `trace_config_proto_go` have
 # the same importpath, and so cause a compile issue if both are depended on
 # directly by another `go_proto_library` (such as `trace_service_proto_go`).