build: Add ability to generate package-level go protos

bazel/BUILD

@@ -0,0 +1,12 @@
+load("@io_bazel_rules_go//proto:compiler.bzl", "go_proto_compiler")
+
+licenses(["notice"])  # Apache 2
+
+go_proto_compiler(
+    name = "pgv_plugin_go",
+    options = ["lang=go"],
+    plugin = "@com_envoyproxy_protoc_gen_validate//:protoc-gen-validate",
+    suffix = ".pb.validate.go",
+    valid_archive = False,
+    visibility = ["//visibility:public"],
+)

bazel/api_build_system.bzl

@@ -1,8 +1,25 @@
 load("@com_google_protobuf//:protobuf.bzl", _py_proto_library = "py_proto_library")
 load("@com_envoyproxy_protoc_gen_validate//bazel:pgv_proto_library.bzl", "pgv_cc_proto_library")
+load("@io_bazel_rules_go//proto:def.bzl", "go_grpc_library", "go_proto_library")
 
 _PY_SUFFIX = "_py"
 _CC_SUFFIX = "_cc"
+_GO_SUFFIX = "_go"
+_GO_IMPORTPATH_PREFIX = "github.com/cncf/udpa/"
+
+_COMMON_PROTO_DEPS = [
+    "@com_google_protobuf//:any_proto",
+    "@com_google_protobuf//:descriptor_proto",
+    "@com_google_protobuf//:duration_proto",
+    "@com_google_protobuf//:empty_proto",
+    "@com_google_protobuf//:struct_proto",
+    "@com_google_protobuf//:timestamp_proto",
+    "@com_google_protobuf//:wrappers_proto",
+    "@com_google_googleapis//google/api:http_proto",
+    "@com_google_googleapis//google/api:annotations_proto",
+    "@com_google_googleapis//google/rpc:status_proto",
+    "@com_envoyproxy_protoc_gen_validate//validate:validate_proto",
+]
 
 def _Suffix(d, suffix):
     return d + suffix
@@ -25,19 +42,7 @@ def udpa_proto_library(
     native.proto_library(
         name = name,
         srcs = srcs,
-        deps = deps + [
-            "@com_google_protobuf//:any_proto",
-            "@com_google_protobuf//:descriptor_proto",
-            "@com_google_protobuf//:duration_proto",
-            "@com_google_protobuf//:empty_proto",
-            "@com_google_protobuf//:struct_proto",
-            "@com_google_protobuf//:timestamp_proto",
-            "@com_google_protobuf//:wrappers_proto",
-            "@com_google_googleapis//google/api:http_proto",
-            "@com_google_googleapis//google/api:annotations_proto",
-            "@com_google_googleapis//google/rpc:status_proto",
-            "@com_envoyproxy_protoc_gen_validate//validate:validate_proto",
-        ],
+        deps = deps + _COMMON_PROTO_DEPS,
         visibility = visibility,
     )
     pgv_cc_proto_library(
@@ -102,3 +107,47 @@ def py_proto_library(name, deps = []):
         deps = proto_deps + ["@com_google_protobuf//:protobuf_python"],
         visibility = ["//visibility:public"],
     )
+
+def udpa_proto_package(name = "pkg", srcs = [], deps = [], has_services = False, visibility = ["//visibility:public"]):
+    """
+    Generate a single go_proto for all protos in the package.
+
+    Some packages may have multiple proto files, and therefore multiple blaze proto targets.
+    For golang, this is not ideal. Non-bazel users will have to manually generate the protos in a different structure.
+    Instead of generating a go_proto target per proto, this rule generates a single go_proto target
+    for the entire package. This better adheres to golang's import structure in the OSS world.
+
+    More information: https://github.com/envoyproxy/envoy/pull/8003
+    """
+    if srcs == []:
+        srcs = native.glob(["*.proto"])
+
+    native.proto_library(
+        name = name,
+        srcs = srcs,
+        deps = deps + _COMMON_PROTO_DEPS,
+        visibility = visibility,
+    )
+
+    compilers = ["@io_bazel_rules_go//proto:go_proto", "//bazel:pgv_plugin_go"]
+    if has_services:
+        compilers = ["@io_bazel_rules_go//proto:go_grpc", "//bazel:pgv_plugin_go"]
+
+    go_proto_library(
+        name = _Suffix(name, _GO_SUFFIX),
+        compilers = compilers,
+        importpath = _Suffix(_GO_IMPORTPATH_PREFIX, native.package_name()),
+        proto = name,
+        visibility = ["//visibility:public"],
+        deps = [_LibrarySuffix(d, _GO_SUFFIX) for d in deps] + [
+            "@com_github_golang_protobuf//ptypes:go_default_library",
+            "@com_github_golang_protobuf//ptypes/any:go_default_library",
+            "@com_github_golang_protobuf//ptypes/duration:go_default_library",
+            "@com_github_golang_protobuf//ptypes/struct:go_default_library",
+            "@com_github_golang_protobuf//ptypes/timestamp:go_default_library",
+            "@com_github_golang_protobuf//ptypes/wrappers:go_default_library",
+            "@com_envoyproxy_protoc_gen_validate//validate:go_default_library",
+            "@com_google_googleapis//google/api:annotations_go_proto",
+            "@com_google_googleapis//google/rpc:status_go_proto",
+        ],
+    )

bazel/dependency_imports.bzl

@@ -21,3 +21,25 @@ def udpa_dependency_imports(go_version = GO_VERSION):
             "py_proto_library": "@com_github_cncf_udpa//bazel:api_build_system.bzl",
         },
     )
+
+    go_repository(
+        name = "org_golang_google_grpc",
+        build_file_proto_mode = "disable",
+        importpath = "google.golang.org/grpc",
+        sum = "h1:AzbTB6ux+okLTzP8Ru1Xs41C303zdcfEht7MQnYJt5A=",
+        version = "v1.23.0",
+    )
+
+    go_repository(
+        name = "org_golang_x_net",
+        importpath = "golang.org/x/net",
+        sum = "h1:fHDIZ2oxGnUZRN6WgWFCbYBjH9uqVPRCUVUDhs0wnbA=",
+        version = "v0.0.0-20190813141303-74dc4d7220e7",
+    )
+
+    go_repository(
+        name = "org_golang_x_text",
+        importpath = "golang.org/x/text",
+        sum = "h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=",
+        version = "v0.3.0",
+    )

udpa/data/orca/v1/BUILD

@@ -1,4 +1,4 @@
-load("//bazel:api_build_system.bzl", "udpa_proto_library")
+load("//bazel:api_build_system.bzl", "udpa_proto_library", "udpa_proto_package")
 
 licenses(["notice"])  # Apache 2
 
@@ -7,3 +7,5 @@ udpa_proto_library(
     srcs = ["orca_load_report.proto"],
     visibility = ["//visibility:public"],
 )
+
+udpa_proto_package()

udpa/data/orca/v1/orca_load_report.proto

@@ -5,7 +5,6 @@ package udpa.data.orca.v1;
 option java_outer_classname = "OrcaLoadReportProto";
 option java_multiple_files = true;
 option java_package = "com.github.udpa.udpa.data.orca.v1";
-option go_package = "v1";
 
 import "validate/validate.proto";
 

udpa/service/orca/v1/BUILD

@@ -1,10 +1,19 @@
-load("//bazel:api_build_system.bzl", "udpa_proto_library")
+load("//bazel:api_build_system.bzl", "udpa_proto_library", "udpa_proto_package")
 
 licenses(["notice"])  # Apache 2
 
 udpa_proto_library(
     name = "orca",
     srcs = ["orca.proto"],
-    has_services = 1,
-    deps = ["//udpa/data/orca/v1:orca_load_report"],
+    has_services = True,
+    deps = [
+        "//udpa/data/orca/v1:orca_load_report",
+    ],
+)
+
+udpa_proto_package(
+    has_services = True,
+    deps = [
+        "//udpa/data/orca/v1:pkg",
+    ],
 )

udpa/service/orca/v1/orca.proto

@@ -5,7 +5,6 @@ package udpa.service.orca.v1;
 option java_outer_classname = "OrcaProto";
 option java_multiple_files = true;
 option java_package = "com.github.udpa.udpa.service.orca.v1";
-option go_package = "v1";
 
 import "udpa/data/orca/v1/orca_load_report.proto";