From ce46d96a8c87e00d5d0ccf445e36508a32b74ade Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Thu, 5 Jul 2018 13:39:28 +0700
Subject: [PATCH 01/20] grpc-json: handle google.api.HttpBody

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 api/bazel/repositories.bzl                    |  3 ++
 .../grpc_json_transcoder_filter.rst           | 11 +++++
 docs/root/intro/version_history.rst           |  7 ++--
 .../filters/http/grpc_json_transcoder/BUILD   |  1 +
 .../json_transcoder_filter.cc                 | 29 +++++++++++++
 .../json_transcoder_filter.h                  |  2 +
 .../json_transcoder_filter_test.cc            | 41 +++++++++++++++++++
 test/proto/bookstore.proto                    |  6 +++
 8 files changed, 97 insertions(+), 3 deletions(-)

diff --git a/api/bazel/repositories.bzl b/api/bazel/repositories.bzl
index b1550bf7851a..af2b42586bdb 100644
--- a/api/bazel/repositories.bzl
+++ b/api/bazel/repositories.bzl
@@ -26,6 +26,7 @@ filegroup(
     srcs = [
         "google/api/annotations.proto",
         "google/api/http.proto",
+        "google/api/httpbody.proto",
     ],
     visibility = ["//visibility:public"],
  )
@@ -49,6 +50,7 @@ cc_proto_library(
     srcs = [
         "google/api/annotations.proto",
         "google/api/http.proto",
+        "google/api/httpbody.proto",
     ],
     default_runtime = "@com_google_protobuf//:protobuf",
     protoc = "@com_google_protobuf//:protoc",
@@ -61,6 +63,7 @@ py_proto_library(
     srcs = [
         "google/api/annotations.proto",
         "google/api/http.proto",
+        "google/api/httpbody.proto",
     ],
     include = ".",
     default_runtime = "@com_google_protobuf//:protobuf_python",
diff --git a/docs/root/configuration/http_filters/grpc_json_transcoder_filter.rst b/docs/root/configuration/http_filters/grpc_json_transcoder_filter.rst
index 0c77708dbac5..b6cb4f3a4b7c 100644
--- a/docs/root/configuration/http_filters/grpc_json_transcoder_filter.rst
+++ b/docs/root/configuration/http_filters/grpc_json_transcoder_filter.rst
@@ -62,3 +62,14 @@ match the incoming request path, set `match_incoming_request_route` to true.
       };
     }
   }
+
+Sending arbitrary content
+-------------------------
+
+By default, when transcoding occurs, gRPC-JSON encodes the message output of a gRPC service method into
+JSON and sets the response `Content-Type` header to `application/json`. To send abritrary content, a gRPC
+service method can use
+`google.api.HttpBody <https://github.com/googleapis/googleapis/blob/master/google/api/httpbody.proto>`_
+as its output message type. The implementation needs to set
+`content_type <https://github.com/googleapis/googleapis/blob/master/google/api/httpbody.proto#L68>`_
+and `data <https://github.com/googleapis/googleapis/blob/master/google/api/httpbody.proto#L71>`_ accordingly.
\ No newline at end of file
diff --git a/docs/root/intro/version_history.rst b/docs/root/intro/version_history.rst
index dbdb78cb2bdb..dfdac57064a1 100644
--- a/docs/root/intro/version_history.rst
+++ b/docs/root/intro/version_history.rst
@@ -3,10 +3,11 @@ Version history
 
 1.8.0 (Pending)
 ===============
-* access log: added :ref:`response flag filter <envoy_api_msg_config.filter.accesslog.v2.ResponseFlagFilter>` 
-  to filter based on the presence of Envoy response flags. 
-* admin: added :http:get:`/hystrix_event_stream` as an endpoint for monitoring envoy's statistics 
+* access log: added :ref:`response flag filter <envoy_api_msg_config.filter.accesslog.v2.ResponseFlagFilter>`
+  to filter based on the presence of Envoy response flags.
+* admin: added :http:get:`/hystrix_event_stream` as an endpoint for monitoring envoy's statistics
   through `Hystrix dashboard <https://github.com/Netflix-Skunkworks/hystrix-dashboard/wiki>`_.
+* grpc-json: added support for encoding `google.api.HttpBody <https://github.com/googleapis/googleapis/blob/master/google/api/httpbody.proto>`_.
 * http: response filters not applied to early error paths such as http_parser generated 400s.
 * lua: added :ref:`requestInfo() <config_http_filters_lua_request_info_wrapper>` wrapper and *protocol()* API.
 * ratelimit: added support for :repo:`api/envoy/service/ratelimit/v2/rls.proto`.
diff --git a/source/extensions/filters/http/grpc_json_transcoder/BUILD b/source/extensions/filters/http/grpc_json_transcoder/BUILD
index 5bf972b6ac8e..b7237d82ab90 100644
--- a/source/extensions/filters/http/grpc_json_transcoder/BUILD
+++ b/source/extensions/filters/http/grpc_json_transcoder/BUILD
@@ -27,6 +27,7 @@ envoy_cc_library(
         "//source/common/grpc:codec_lib",
         "//source/common/grpc:common_lib",
         "//source/common/http:headers_lib",
+        "//source/common/json:json_loader_lib",
         "//source/common/protobuf",
         "@envoy_api//envoy/config/filter/http/transcoder/v2:transcoder_cc",
     ],
diff --git a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
index 4328fb2ab760..298edeb965b6 100644
--- a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
+++ b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
@@ -4,16 +4,19 @@
 #include "envoy/http/filter.h"
 
 #include "common/common/assert.h"
+#include "common/common/base64.h"
 #include "common/common/enum_to_int.h"
 #include "common/common/utility.h"
 #include "common/filesystem/filesystem_impl.h"
 #include "common/grpc/common.h"
 #include "common/http/headers.h"
 #include "common/http/utility.h"
+#include "common/json/json_loader.h"
 #include "common/protobuf/protobuf.h"
 
 #include "google/api/annotations.pb.h"
 #include "google/api/http.pb.h"
+#include "google/api/httpbody.pb.h"
 #include "grpc_transcoding/json_request_translator.h"
 #include "grpc_transcoding/path_matcher_utility.h"
 #include "grpc_transcoding/response_to_json_translator.h"
@@ -349,6 +352,10 @@ Http::FilterDataStatus JsonTranscoderFilter::encodeData(Buffer::Instance& data,
   readToBuffer(*transcoder_->ResponseOutput(), data);
 
   if (!method_->server_streaming() && !end_stream) {
+    if (hasHttpBodyAsOutputType()) {
+      // Set content-type and data from HttpBody.
+      buildResponseFromHttpBodyOutput(*response_headers_, data);
+    }
     // Buffer until the response is complete.
     return Http::FilterDataStatus::StopIterationAndBuffer;
   }
@@ -415,6 +422,28 @@ bool JsonTranscoderFilter::readToBuffer(Protobuf::io::ZeroCopyInputStream& strea
   return false;
 }
 
+void JsonTranscoderFilter::buildResponseFromHttpBodyOutput(Http::HeaderMap& response_headers,
+                                                           Buffer::Instance& data) {
+  // TODO(dio): Wrap JSON parsing in a try-catch block.
+  const Json::ObjectSharedPtr http_body = Json::Factory::loadFromString(data.toString());
+  const std::string decoded_body = Base64::decode(http_body->getString("data"));
+
+  data.drain(data.length());
+  data.add(decoded_body);
+
+  response_headers.insertContentType().value(http_body->getString("contentType"));
+  response_headers.insertContentLength().value(decoded_body.size());
+}
+
+bool JsonTranscoderFilter::hasHttpBodyAsOutputType() {
+  absl::string_view output_type = method_->output_type()->full_name();
+  absl::string_view http_body_type = google::api::HttpBody::descriptor()->full_name();
+  if (output_type.length() != http_body_type.length()) {
+    return false;
+  }
+  return StringUtil::startsWith(output_type.data(), http_body_type.data(), true);
+}
+
 } // namespace GrpcJsonTranscoder
 } // namespace HttpFilters
 } // namespace Extensions
diff --git a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.h b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.h
index e8544ea2600f..922efaf49034 100644
--- a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.h
+++ b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.h
@@ -117,6 +117,8 @@ class JsonTranscoderFilter : public Http::StreamFilter, public Logger::Loggable<
 
 private:
   bool readToBuffer(Protobuf::io::ZeroCopyInputStream& stream, Buffer::Instance& data);
+  void buildResponseFromHttpBodyOutput(Http::HeaderMap& response_headers, Buffer::Instance& data);
+  bool hasHttpBodyAsOutputType();
 
   JsonTranscoderConfig& config_;
   std::unique_ptr<google::grpc::transcoding::Transcoder> transcoder_;
diff --git a/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc b/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc
index e3c96bb95dd9..61cfb9e4de51 100644
--- a/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc
+++ b/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc
@@ -550,6 +550,47 @@ TEST_F(GrpcJsonTranscoderFilterTest, TranscodingUnaryNotGrpcResponse) {
   EXPECT_EQ(Http::FilterDataStatus::Continue, filter_.encodeData(request_data, true));
 }
 
+TEST_F(GrpcJsonTranscoderFilterTest, TranscodingUnaryWithHttpBodyAsOutput) {
+  Http::TestHeaderMapImpl request_headers{{":method", "GET"}, {":path", "/index"}};
+
+  EXPECT_CALL(decoder_callbacks_, clearRouteCache());
+
+  EXPECT_EQ(Http::FilterHeadersStatus::Continue, filter_.decodeHeaders(request_headers, false));
+  EXPECT_EQ("application/grpc", request_headers.get_("content-type"));
+  EXPECT_EQ("/index", request_headers.get_("x-envoy-original-path"));
+  EXPECT_EQ("/bookstore.Bookstore/GetIndex", request_headers.get_(":path"));
+  EXPECT_EQ("trailers", request_headers.get_("te"));
+
+  Http::TestHeaderMapImpl continue_headers{{":status", "000"}};
+  EXPECT_EQ(Http::FilterHeadersStatus::Continue,
+            filter_.encode100ContinueHeaders(continue_headers));
+
+  Http::TestHeaderMapImpl response_headers{{"content-type", "application/grpc"},
+                                           {":status", "200"}};
+
+  EXPECT_EQ(Http::FilterHeadersStatus::StopIteration,
+            filter_.encodeHeaders(response_headers, false));
+  EXPECT_EQ("application/json", response_headers.get_("content-type"));
+
+  google::api::HttpBody response;
+  response.set_content_type("text/html");
+  response.set_data("<h1>Hello, world!</h1>");
+
+  auto response_data = Grpc::Common::serializeBody(response);
+
+  EXPECT_EQ(Http::FilterDataStatus::StopIterationAndBuffer,
+            filter_.encodeData(*response_data, false));
+
+  std::string response_html = response_data->toString();
+
+  EXPECT_EQ("text/html", response_headers.get_("content-type"));
+  EXPECT_EQ("<h1>Hello, world!</h1>", response_html);
+
+  Http::TestHeaderMapImpl response_trailers{{"grpc-status", "0"}, {"grpc-message", ""}};
+
+  EXPECT_EQ(Http::FilterTrailersStatus::Continue, filter_.decodeTrailers(response_trailers));
+}
+
 struct GrpcJsonTranscoderFilterPrintTestParam {
   std::string config_json_;
   std::string expected_response_;
diff --git a/test/proto/bookstore.proto b/test/proto/bookstore.proto
index 45ca15bf54c6..6fb65b42d119 100644
--- a/test/proto/bookstore.proto
+++ b/test/proto/bookstore.proto
@@ -3,6 +3,7 @@ syntax = "proto3";
 package bookstore;
 
 import "google/api/annotations.proto";
+import "google/api/httpbody.proto";
 import "google/protobuf/empty.proto";
 
 // A simple Bookstore API.
@@ -84,6 +85,11 @@ service Bookstore {
       get: "/authors/{author}"
     };
   }
+  rpc GetIndex(google.protobuf.Empty) returns (google.api.HttpBody) {
+    option (google.api.http) = {
+      get: "/index"
+    };
+  }
 }
 
 // A shelf resource.

From aa8e4cf2a0ae186931daf1557b9d86d6ba97f1b6 Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Thu, 5 Jul 2018 16:01:52 +0700
Subject: [PATCH 02/20] Wrap in exception

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 .../json_transcoder_filter.cc                  | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
index 298edeb965b6..5fce8c489094 100644
--- a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
+++ b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
@@ -424,15 +424,19 @@ bool JsonTranscoderFilter::readToBuffer(Protobuf::io::ZeroCopyInputStream& strea
 
 void JsonTranscoderFilter::buildResponseFromHttpBodyOutput(Http::HeaderMap& response_headers,
                                                            Buffer::Instance& data) {
-  // TODO(dio): Wrap JSON parsing in a try-catch block.
-  const Json::ObjectSharedPtr http_body = Json::Factory::loadFromString(data.toString());
-  const std::string decoded_body = Base64::decode(http_body->getString("data"));
+  try {
+    const Json::ObjectSharedPtr http_body = Json::Factory::loadFromString(data.toString());
+    const std::string decoded_body = Base64::decode(http_body->getString("data"));
 
-  data.drain(data.length());
-  data.add(decoded_body);
+    data.drain(data.length());
+    data.add(decoded_body);
 
-  response_headers.insertContentType().value(http_body->getString("contentType"));
-  response_headers.insertContentLength().value(decoded_body.size());
+    response_headers.insertContentType().value(http_body->getString("contentType"));
+    response_headers.insertContentLength().value(decoded_body.size());
+  } catch (const Json::Exception& e) {
+    ENVOY_LOG(debug, "Failed to parse output of '{}'. e.what(): {}",
+              method_->input_type()->full_name(), e.what());
+  }
 }
 
 bool JsonTranscoderFilter::hasHttpBodyAsOutputType() {

From ac4455bd1423b4d823ae834d289f07855024633a Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Thu, 5 Jul 2018 16:05:15 +0700
Subject: [PATCH 03/20] Log method name instead

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 .../http/grpc_json_transcoder/json_transcoder_filter.cc       | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
index 5fce8c489094..daf8e0bbf794 100644
--- a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
+++ b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
@@ -434,8 +434,8 @@ void JsonTranscoderFilter::buildResponseFromHttpBodyOutput(Http::HeaderMap& resp
     response_headers.insertContentType().value(http_body->getString("contentType"));
     response_headers.insertContentLength().value(decoded_body.size());
   } catch (const Json::Exception& e) {
-    ENVOY_LOG(debug, "Failed to parse output of '{}'. e.what(): {}",
-              method_->input_type()->full_name(), e.what());
+    ENVOY_LOG(debug, "Failed to parse output of '{}'. e.what(): {}", method_->full_name(),
+              e.what());
   }
 }
 

From fcd37be3e67641eacac9bde9fa987ae66f661563 Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Thu, 5 Jul 2018 18:31:50 +0700
Subject: [PATCH 04/20] Add api_httpbody_protos

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 api/bazel/api_build_system.bzl                |  3 ++
 api/bazel/repositories.bzl                    | 54 +++++++++++++++++--
 bazel/envoy_build_system.bzl                  |  8 +++
 bazel/repositories.bzl                        |  4 ++
 .../filters/http/grpc_json_transcoder/BUILD   |  1 +
 test/proto/BUILD                              |  4 +-
 6 files changed, 69 insertions(+), 5 deletions(-)

diff --git a/api/bazel/api_build_system.bzl b/api/bazel/api_build_system.bzl
index 8099e9f025aa..591e40c9b58e 100644
--- a/api/bazel/api_build_system.bzl
+++ b/api/bazel/api_build_system.bzl
@@ -32,6 +32,7 @@ def api_py_proto_library(name, srcs = [], deps = [], has_services = 0):
         protoc = "@com_google_protobuf//:protoc",
         deps = [_LibrarySuffix(d, _PY_SUFFIX) for d in deps] + [
             "@com_lyft_protoc_gen_validate//validate:validate_py",
+            "@googleapis//:api_httpbody_protos_py",
             "@googleapis//:http_api_protos_py",
             "@googleapis//:rpc_status_protos_py",
             "@com_github_gogo_protobuf//:gogo_proto_py",
@@ -108,6 +109,7 @@ def api_proto_library(name, visibility = ["//visibility:private"], srcs = [], de
             "@com_google_protobuf//:struct_proto",
             "@com_google_protobuf//:timestamp_proto",
             "@com_google_protobuf//:wrappers_proto",
+            "@googleapis//:api_httpbody_protos_proto",
             "@googleapis//:http_api_protos_proto",
             "@googleapis//:rpc_status_protos_lib",
             "@com_github_gogo_protobuf//:gogo_proto",
@@ -125,6 +127,7 @@ def api_proto_library(name, visibility = ["//visibility:private"], srcs = [], de
         deps = [_LibrarySuffix(d, _CC_SUFFIX) for d in deps],
         external_deps = [
             "@com_google_protobuf//:cc_wkt_protos",
+            "@googleapis//:api_httpbody_protos",
             "@googleapis//:http_api_protos",
             "@googleapis//:rpc_status_protos",
             "@com_github_gogo_protobuf//:gogo_proto_cc",
diff --git a/api/bazel/repositories.bzl b/api/bazel/repositories.bzl
index af2b42586bdb..da383bf5a34d 100644
--- a/api/bazel/repositories.bzl
+++ b/api/bazel/repositories.bzl
@@ -21,15 +21,62 @@ def api_dependencies():
 load("@com_google_protobuf//:protobuf.bzl", "cc_proto_library", "py_proto_library")
 load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")
 
+filegroup(
+    name = "api_httpbody_protos_src",
+    srcs = [
+        "google/api/httpbody.proto",
+    ],
+    visibility = ["//visibility:public"],
+)
+
+proto_library(
+    name = "api_httpbody_protos_proto",
+    srcs = [":api_httpbody_protos_src"],
+    deps = ["@com_google_protobuf//:descriptor_proto"],
+    visibility = ["//visibility:public"],
+)
+
+cc_proto_library(
+    name = "api_httpbody_protos",
+    srcs = [
+        "google/api/httpbody.proto",
+    ],
+    default_runtime = "@com_google_protobuf//:protobuf",
+    protoc = "@com_google_protobuf//:protoc",
+    deps = ["@com_google_protobuf//:cc_wkt_protos"],
+    visibility = ["//visibility:public"],
+)
+
+py_proto_library(
+    name = "api_httpbody_protos_py",
+    srcs = [
+        "google/api/httpbody.proto",
+    ],
+    include = ".",
+    default_runtime = "@com_google_protobuf//:protobuf_python",
+    protoc = "@com_google_protobuf//:protoc",
+    visibility = ["//visibility:public"],
+    deps = ["@com_google_protobuf//:protobuf_python"],
+)
+
+go_proto_library(
+    name = "api_httpbody_go_proto",
+    importpath = "google.golang.org/genproto/googleapis/api/httpbody",
+    proto = ":api_httpbody_protos_proto",
+    visibility = ["//visibility:public"],
+    deps = [
+      ":descriptor_go_proto",
+    ],
+)
+
 filegroup(
     name = "http_api_protos_src",
     srcs = [
         "google/api/annotations.proto",
         "google/api/http.proto",
-        "google/api/httpbody.proto",
     ],
     visibility = ["//visibility:public"],
- )
+)
 
 go_proto_library(
     name = "descriptor_go_proto",
@@ -50,7 +97,6 @@ cc_proto_library(
     srcs = [
         "google/api/annotations.proto",
         "google/api/http.proto",
-        "google/api/httpbody.proto",
     ],
     default_runtime = "@com_google_protobuf//:protobuf",
     protoc = "@com_google_protobuf//:protoc",
@@ -63,7 +109,6 @@ py_proto_library(
     srcs = [
         "google/api/annotations.proto",
         "google/api/http.proto",
-        "google/api/httpbody.proto",
     ],
     include = ".",
     default_runtime = "@com_google_protobuf//:protobuf_python",
@@ -96,6 +141,7 @@ proto_library(
      deps = ["@com_google_protobuf//:any_proto"],
      visibility = ["//visibility:public"],
 )
+
 cc_proto_library(
      name = "rpc_status_protos",
      srcs = ["google/rpc/status.proto"],
diff --git a/bazel/envoy_build_system.bzl b/bazel/envoy_build_system.bzl
index bf7885cc7d6c..d79663d83739 100644
--- a/bazel/envoy_build_system.bzl
+++ b/bazel/envoy_build_system.bzl
@@ -366,6 +366,10 @@ def envoy_proto_library(name, srcs = [], deps = [], external_deps = [],
     cc_proto_deps = []
     py_proto_deps = ["@com_google_protobuf//:protobuf_python"]
 
+    if "api_httpbody_protos" in external_deps:
+        cc_proto_deps.append("@googleapis//:api_httpbody_protos")
+        py_proto_deps.append("@googleapis//:api_httpbody_protos_py")
+
     if "http_api_protos" in external_deps:
         cc_proto_deps.append("@googleapis//:http_api_protos")
         py_proto_deps.append("@googleapis//:http_api_protos_py")
@@ -403,6 +407,10 @@ def envoy_proto_descriptor(name, out, srcs = [], external_deps = []):
     input_files = ["$(location " + src + ")" for src in srcs]
     include_paths = [".", PACKAGE_NAME]
 
+    if "api_httpbody_protos" in external_deps:
+        srcs.append("@googleapis//:api_httpbody_protos_src")
+        include_paths.append("external/googleapis")
+
     if "http_api_protos" in external_deps:
         srcs.append("@googleapis//:http_api_protos_src")
         include_paths.append("external/googleapis")
diff --git a/bazel/repositories.bzl b/bazel/repositories.bzl
index 6440a3a55c16..09daa9032afd 100644
--- a/bazel/repositories.bzl
+++ b/bazel/repositories.bzl
@@ -182,6 +182,10 @@ def _envoy_api_deps():
     if "envoy_api" not in native.existing_rules().keys():
         _default_envoy_api(name="envoy_api")
 
+    native.bind(
+        name = "api_httpbody_protos",
+        actual = "@googleapis//:api_httpbody_protos",
+    )
     native.bind(
         name = "http_api_protos",
         actual = "@googleapis//:http_api_protos",
diff --git a/source/extensions/filters/http/grpc_json_transcoder/BUILD b/source/extensions/filters/http/grpc_json_transcoder/BUILD
index b7237d82ab90..885b5fb2d651 100644
--- a/source/extensions/filters/http/grpc_json_transcoder/BUILD
+++ b/source/extensions/filters/http/grpc_json_transcoder/BUILD
@@ -19,6 +19,7 @@ envoy_cc_library(
         "path_matcher",
         "grpc_transcoding",
         "http_api_protos",
+        "api_httpbody_protos",
     ],
     deps = [
         ":transcoder_input_stream_lib",
diff --git a/test/proto/BUILD b/test/proto/BUILD
index 3b21fb2d2ea2..fa1674251719 100644
--- a/test/proto/BUILD
+++ b/test/proto/BUILD
@@ -20,8 +20,9 @@ envoy_proto_library(
     name = "bookstore_proto",
     srcs = [":bookstore.proto"],
     external_deps = [
-        "well_known_protos",
+        "api_httpbody_protos",
         "http_api_protos",
+        "well_known_protos",
     ],
 )
 
@@ -32,6 +33,7 @@ envoy_proto_descriptor(
     ],
     out = "bookstore.descriptor",
     external_deps = [
+        "api_httpbody_protos",
         "http_api_protos",
         "well_known_protos",
     ],

From da90483bf543072f88f747f55691289d815e6c6f Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Thu, 5 Jul 2018 19:55:03 +0700
Subject: [PATCH 05/20] Fix on mac api build

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 api/bazel/api_build_system.bzl | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/api/bazel/api_build_system.bzl b/api/bazel/api_build_system.bzl
index 591e40c9b58e..749d03be0afb 100644
--- a/api/bazel/api_build_system.bzl
+++ b/api/bazel/api_build_system.bzl
@@ -127,7 +127,11 @@ def api_proto_library(name, visibility = ["//visibility:private"], srcs = [], de
         deps = [_LibrarySuffix(d, _CC_SUFFIX) for d in deps],
         external_deps = [
             "@com_google_protobuf//:cc_wkt_protos",
-            "@googleapis//:api_httpbody_protos",
+            # TODO(dio): Running `bazel build @envoy_api//envoy/...` on mac
+            # with the following line uncommented gives:
+            # 'error=7, Argument list too long'
+            #
+            # "@googleapis//:api_httpbody_protos",
             "@googleapis//:http_api_protos",
             "@googleapis//:rpc_status_protos",
             "@com_github_gogo_protobuf//:gogo_proto_cc",

From 5aa346a4452c1d8baf2e94601eeb0b875dc1a925 Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Mon, 9 Jul 2018 14:01:10 +0700
Subject: [PATCH 06/20] review: remove comment related to bazel

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 api/bazel/api_build_system.bzl | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/api/bazel/api_build_system.bzl b/api/bazel/api_build_system.bzl
index 749d03be0afb..dfda7bfea629 100644
--- a/api/bazel/api_build_system.bzl
+++ b/api/bazel/api_build_system.bzl
@@ -127,11 +127,6 @@ def api_proto_library(name, visibility = ["//visibility:private"], srcs = [], de
         deps = [_LibrarySuffix(d, _CC_SUFFIX) for d in deps],
         external_deps = [
             "@com_google_protobuf//:cc_wkt_protos",
-            # TODO(dio): Running `bazel build @envoy_api//envoy/...` on mac
-            # with the following line uncommented gives:
-            # 'error=7, Argument list too long'
-            #
-            # "@googleapis//:api_httpbody_protos",
             "@googleapis//:http_api_protos",
             "@googleapis//:rpc_status_protos",
             "@com_github_gogo_protobuf//:gogo_proto_cc",

From 9f4739bbe9304d46044d5474e43f1f929adafdaf Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Mon, 9 Jul 2018 14:18:02 +0700
Subject: [PATCH 07/20] review: use equal operator instead

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 .../http/grpc_json_transcoder/json_transcoder_filter.cc    | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
index daf8e0bbf794..3b2919776d6b 100644
--- a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
+++ b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
@@ -440,12 +440,7 @@ void JsonTranscoderFilter::buildResponseFromHttpBodyOutput(Http::HeaderMap& resp
 }
 
 bool JsonTranscoderFilter::hasHttpBodyAsOutputType() {
-  absl::string_view output_type = method_->output_type()->full_name();
-  absl::string_view http_body_type = google::api::HttpBody::descriptor()->full_name();
-  if (output_type.length() != http_body_type.length()) {
-    return false;
-  }
-  return StringUtil::startsWith(output_type.data(), http_body_type.data(), true);
+  return method_->output_type()->full_name() == google::api::HttpBody::descriptor()->full_name();
 }
 
 } // namespace GrpcJsonTranscoder

From 95778e8d1dbe4a2493caa36f24e705b39d2066a2 Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Mon, 9 Jul 2018 21:35:42 +0700
Subject: [PATCH 08/20] review: clarify on supporting response only

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 docs/root/intro/version_history.rst           |  3 +-
 .../filters/http/grpc_json_transcoder/BUILD   |  1 -
 .../json_transcoder_filter.cc                 | 43 +++++++++++--------
 .../json_transcoder_filter.h                  |  5 ++-
 4 files changed, 31 insertions(+), 21 deletions(-)

diff --git a/docs/root/intro/version_history.rst b/docs/root/intro/version_history.rst
index 3a948d2defa3..f76b71192519 100644
--- a/docs/root/intro/version_history.rst
+++ b/docs/root/intro/version_history.rst
@@ -7,7 +7,8 @@ Version history
   to filter based on the presence of Envoy response flags.
 * admin: added :http:get:`/hystrix_event_stream` as an endpoint for monitoring envoy's statistics
   through `Hystrix dashboard <https://github.com/Netflix-Skunkworks/hystrix-dashboard/wiki>`_.
-* grpc-json: added support for encoding `google.api.HttpBody <https://github.com/googleapis/googleapis/blob/master/google/api/httpbody.proto>`_.
+* grpc-json: added support for building HTTP response from
+  `google.api.HttpBody <https://github.com/googleapis/googleapis/blob/master/google/api/httpbody.proto>`_.
 * health check: added support for :ref:`custom health check <envoy_api_field_core.HealthCheck.custom_health_check>`.
 * health_check: added support for :ref:`health check event logging <arch_overview_health_check_logging>`.
 * http: response filters not applied to early error paths such as http_parser generated 400s.
diff --git a/source/extensions/filters/http/grpc_json_transcoder/BUILD b/source/extensions/filters/http/grpc_json_transcoder/BUILD
index 885b5fb2d651..f908f7e3c942 100644
--- a/source/extensions/filters/http/grpc_json_transcoder/BUILD
+++ b/source/extensions/filters/http/grpc_json_transcoder/BUILD
@@ -28,7 +28,6 @@ envoy_cc_library(
         "//source/common/grpc:codec_lib",
         "//source/common/grpc:common_lib",
         "//source/common/http:headers_lib",
-        "//source/common/json:json_loader_lib",
         "//source/common/protobuf",
         "@envoy_api//envoy/config/filter/http/transcoder/v2:transcoder_cc",
     ],
diff --git a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
index 3b2919776d6b..993bcbff2448 100644
--- a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
+++ b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
@@ -11,7 +11,6 @@
 #include "common/grpc/common.h"
 #include "common/http/headers.h"
 #include "common/http/utility.h"
-#include "common/json/json_loader.h"
 #include "common/protobuf/protobuf.h"
 
 #include "google/api/annotations.pb.h"
@@ -225,6 +224,7 @@ Http::FilterHeadersStatus JsonTranscoderFilter::decodeHeaders(Http::HeaderMap& h
     // just pass-through the request to upstream.
     return Http::FilterHeadersStatus::Continue;
   }
+  has_http_body_output_ = hasHttpBodyAsOutputType();
 
   headers.removeContentLength();
   headers.insertContentType().value().setReference(Http::Headers::get().ContentTypeValues.Grpc);
@@ -343,6 +343,10 @@ Http::FilterDataStatus JsonTranscoderFilter::encodeData(Buffer::Instance& data,
     return Http::FilterDataStatus::Continue;
   }
 
+  if (has_http_body_output_ && buildResponseFromHttpBodyOutput(*response_headers_, data)) {
+    return Http::FilterDataStatus::StopIterationAndBuffer;
+  }
+
   response_in_.move(data);
 
   if (end_stream) {
@@ -352,13 +356,10 @@ Http::FilterDataStatus JsonTranscoderFilter::encodeData(Buffer::Instance& data,
   readToBuffer(*transcoder_->ResponseOutput(), data);
 
   if (!method_->server_streaming() && !end_stream) {
-    if (hasHttpBodyAsOutputType()) {
-      // Set content-type and data from HttpBody.
-      buildResponseFromHttpBodyOutput(*response_headers_, data);
-    }
     // Buffer until the response is complete.
     return Http::FilterDataStatus::StopIterationAndBuffer;
   }
+  // TODO(dio): Add support for streaming case.
   // TODO(lizan): Check ResponseStatus
 
   return Http::FilterDataStatus::Continue;
@@ -422,21 +423,27 @@ bool JsonTranscoderFilter::readToBuffer(Protobuf::io::ZeroCopyInputStream& strea
   return false;
 }
 
-void JsonTranscoderFilter::buildResponseFromHttpBodyOutput(Http::HeaderMap& response_headers,
+bool JsonTranscoderFilter::buildResponseFromHttpBodyOutput(Http::HeaderMap& response_headers,
                                                            Buffer::Instance& data) {
-  try {
-    const Json::ObjectSharedPtr http_body = Json::Factory::loadFromString(data.toString());
-    const std::string decoded_body = Base64::decode(http_body->getString("data"));
-
-    data.drain(data.length());
-    data.add(decoded_body);
-
-    response_headers.insertContentType().value(http_body->getString("contentType"));
-    response_headers.insertContentLength().value(decoded_body.size());
-  } catch (const Json::Exception& e) {
-    ENVOY_LOG(debug, "Failed to parse output of '{}'. e.what(): {}", method_->full_name(),
-              e.what());
+  std::vector<Grpc::Frame> frames;
+  decoder_.decode(data, frames);
+  if (frames.empty()) {
+    return true;
+  }
+
+  google::api::HttpBody http_body;
+  for (auto& frame : frames) {
+    if (frame.length_ > 0) {
+      Buffer::ZeroCopyInputStreamImpl stream(std::move(frame.data_));
+      http_body.ParseFromZeroCopyStream(&stream);
+      const auto& body = http_body.data();
+      data.add(body);
+      response_headers.insertContentType().value(http_body.content_type());
+      response_headers.insertContentLength().value(body.length());
+      return true;
+    }
   }
+  return false;
 }
 
 bool JsonTranscoderFilter::hasHttpBodyAsOutputType() {
diff --git a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.h b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.h
index 922efaf49034..f796d620a53c 100644
--- a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.h
+++ b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.h
@@ -7,6 +7,7 @@
 #include "envoy/json/json_object.h"
 
 #include "common/common/logger.h"
+#include "common/grpc/codec.h"
 #include "common/protobuf/protobuf.h"
 
 #include "extensions/filters/http/grpc_json_transcoder/transcoder_input_stream_impl.h"
@@ -117,7 +118,7 @@ class JsonTranscoderFilter : public Http::StreamFilter, public Logger::Loggable<
 
 private:
   bool readToBuffer(Protobuf::io::ZeroCopyInputStream& stream, Buffer::Instance& data);
-  void buildResponseFromHttpBodyOutput(Http::HeaderMap& response_headers, Buffer::Instance& data);
+  bool buildResponseFromHttpBodyOutput(Http::HeaderMap& response_headers, Buffer::Instance& data);
   bool hasHttpBodyAsOutputType();
 
   JsonTranscoderConfig& config_;
@@ -128,8 +129,10 @@ class JsonTranscoderFilter : public Http::StreamFilter, public Logger::Loggable<
   Http::StreamEncoderFilterCallbacks* encoder_callbacks_{nullptr};
   const Protobuf::MethodDescriptor* method_{nullptr};
   Http::HeaderMap* response_headers_{nullptr};
+  Grpc::Decoder decoder_;
 
   bool error_{false};
+  bool has_http_body_output_{false};
 };
 
 } // namespace GrpcJsonTranscoder

From e76880e2fd60fdd937b18209a706d5b28ca23d20 Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Mon, 9 Jul 2018 21:49:15 +0700
Subject: [PATCH 09/20] Remove base64

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 source/extensions/filters/http/grpc_json_transcoder/BUILD        | 1 -
 .../filters/http/grpc_json_transcoder/json_transcoder_filter.cc  | 1 -
 2 files changed, 2 deletions(-)

diff --git a/source/extensions/filters/http/grpc_json_transcoder/BUILD b/source/extensions/filters/http/grpc_json_transcoder/BUILD
index f908f7e3c942..f411adf589ac 100644
--- a/source/extensions/filters/http/grpc_json_transcoder/BUILD
+++ b/source/extensions/filters/http/grpc_json_transcoder/BUILD
@@ -24,7 +24,6 @@ envoy_cc_library(
     deps = [
         ":transcoder_input_stream_lib",
         "//include/envoy/http:filter_interface",
-        "//source/common/common:base64_lib",
         "//source/common/grpc:codec_lib",
         "//source/common/grpc:common_lib",
         "//source/common/http:headers_lib",
diff --git a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
index 993bcbff2448..111382f0ddba 100644
--- a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
+++ b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
@@ -4,7 +4,6 @@
 #include "envoy/http/filter.h"
 
 #include "common/common/assert.h"
-#include "common/common/base64.h"
 #include "common/common/enum_to_int.h"
 #include "common/common/utility.h"
 #include "common/filesystem/filesystem_impl.h"

From 3aa68fb2d5b59865797608742ffd5e6744a50813 Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Tue, 10 Jul 2018 14:55:11 +0700
Subject: [PATCH 10/20] Process only one frame for now

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 .../grpc_json_transcoder/json_transcoder_filter.cc     | 10 +++++-----
 .../http/grpc_json_transcoder/json_transcoder_filter.h |  2 +-
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
index 111382f0ddba..6927ff0fec57 100644
--- a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
+++ b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
@@ -342,7 +342,8 @@ Http::FilterDataStatus JsonTranscoderFilter::encodeData(Buffer::Instance& data,
     return Http::FilterDataStatus::Continue;
   }
 
-  if (has_http_body_output_ && buildResponseFromHttpBodyOutput(*response_headers_, data)) {
+  if (has_http_body_output_) {
+    buildResponseFromHttpBodyOutput(*response_headers_, data);
     return Http::FilterDataStatus::StopIterationAndBuffer;
   }
 
@@ -422,12 +423,12 @@ bool JsonTranscoderFilter::readToBuffer(Protobuf::io::ZeroCopyInputStream& strea
   return false;
 }
 
-bool JsonTranscoderFilter::buildResponseFromHttpBodyOutput(Http::HeaderMap& response_headers,
+void JsonTranscoderFilter::buildResponseFromHttpBodyOutput(Http::HeaderMap& response_headers,
                                                            Buffer::Instance& data) {
   std::vector<Grpc::Frame> frames;
   decoder_.decode(data, frames);
   if (frames.empty()) {
-    return true;
+    return;
   }
 
   google::api::HttpBody http_body;
@@ -439,10 +440,9 @@ bool JsonTranscoderFilter::buildResponseFromHttpBodyOutput(Http::HeaderMap& resp
       data.add(body);
       response_headers.insertContentType().value(http_body.content_type());
       response_headers.insertContentLength().value(body.length());
-      return true;
+      return;
     }
   }
-  return false;
 }
 
 bool JsonTranscoderFilter::hasHttpBodyAsOutputType() {
diff --git a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.h b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.h
index f796d620a53c..5849bcc96b2f 100644
--- a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.h
+++ b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.h
@@ -118,7 +118,7 @@ class JsonTranscoderFilter : public Http::StreamFilter, public Logger::Loggable<
 
 private:
   bool readToBuffer(Protobuf::io::ZeroCopyInputStream& stream, Buffer::Instance& data);
-  bool buildResponseFromHttpBodyOutput(Http::HeaderMap& response_headers, Buffer::Instance& data);
+  void buildResponseFromHttpBodyOutput(Http::HeaderMap& response_headers, Buffer::Instance& data);
   bool hasHttpBodyAsOutputType();
 
   JsonTranscoderConfig& config_;

From 4123018b7f9ba43691c12f4414d89d394fcde0c0 Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Wed, 11 Jul 2018 09:57:24 +0700
Subject: [PATCH 11/20] review: move comment, set when !server_streaming

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 .../json_transcoder_filter.cc                     | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
index 6927ff0fec57..f3b9b6291b09 100644
--- a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
+++ b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
@@ -225,12 +225,14 @@ Http::FilterHeadersStatus JsonTranscoderFilter::decodeHeaders(Http::HeaderMap& h
   }
   has_http_body_output_ = hasHttpBodyAsOutputType();
 
-  headers.removeContentLength();
-  headers.insertContentType().value().setReference(Http::Headers::get().ContentTypeValues.Grpc);
-  headers.insertEnvoyOriginalPath().value(*headers.Path());
-  headers.insertPath().value("/" + method_->service()->full_name() + "/" + method_->name());
-  headers.insertMethod().value().setReference(Http::Headers::get().MethodValues.Post);
-  headers.insertTE().value().setReference(Http::Headers::get().TEValues.Trailers);
+  if (!method_->server_streaming()) {
+    headers.removeContentLength();
+    headers.insertContentType().value().setReference(Http::Headers::get().ContentTypeValues.Grpc);
+    headers.insertEnvoyOriginalPath().value(*headers.Path());
+    headers.insertPath().value("/" + method_->service()->full_name() + "/" + method_->name());
+    headers.insertMethod().value().setReference(Http::Headers::get().MethodValues.Post);
+    headers.insertTE().value().setReference(Http::Headers::get().TEValues.Trailers);
+  }
 
   if (!config_.matchIncomingRequestInfo()) {
     decoder_callbacks_->clearRouteCache();
@@ -342,6 +344,7 @@ Http::FilterDataStatus JsonTranscoderFilter::encodeData(Buffer::Instance& data,
     return Http::FilterDataStatus::Continue;
   }
 
+  // TODO(dio): Add support for streaming case.
   if (has_http_body_output_) {
     buildResponseFromHttpBodyOutput(*response_headers_, data);
     return Http::FilterDataStatus::StopIterationAndBuffer;

From 085e967851d6c3c69bc96a742ba008376fce1243 Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Wed, 11 Jul 2018 10:00:29 +0700
Subject: [PATCH 12/20] Remove duplicated comments

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 .../filters/http/grpc_json_transcoder/json_transcoder_filter.cc  | 1 -
 1 file changed, 1 deletion(-)

diff --git a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
index f3b9b6291b09..47a75d328782 100644
--- a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
+++ b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
@@ -362,7 +362,6 @@ Http::FilterDataStatus JsonTranscoderFilter::encodeData(Buffer::Instance& data,
     // Buffer until the response is complete.
     return Http::FilterDataStatus::StopIterationAndBuffer;
   }
-  // TODO(dio): Add support for streaming case.
   // TODO(lizan): Check ResponseStatus
 
   return Http::FilterDataStatus::Continue;

From d5c4ba9e88e48b126ebc4dd223a30fefbd5bb86f Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Wed, 11 Jul 2018 13:45:44 +0700
Subject: [PATCH 13/20] Only handle HttpBody when !server_streaming

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 .../json_transcoder_filter.cc                  | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
index 47a75d328782..0d02ea3553dd 100644
--- a/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
+++ b/source/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter.cc
@@ -223,16 +223,14 @@ Http::FilterHeadersStatus JsonTranscoderFilter::decodeHeaders(Http::HeaderMap& h
     // just pass-through the request to upstream.
     return Http::FilterHeadersStatus::Continue;
   }
-  has_http_body_output_ = hasHttpBodyAsOutputType();
-
-  if (!method_->server_streaming()) {
-    headers.removeContentLength();
-    headers.insertContentType().value().setReference(Http::Headers::get().ContentTypeValues.Grpc);
-    headers.insertEnvoyOriginalPath().value(*headers.Path());
-    headers.insertPath().value("/" + method_->service()->full_name() + "/" + method_->name());
-    headers.insertMethod().value().setReference(Http::Headers::get().MethodValues.Post);
-    headers.insertTE().value().setReference(Http::Headers::get().TEValues.Trailers);
-  }
+  has_http_body_output_ = !method_->server_streaming() && hasHttpBodyAsOutputType();
+
+  headers.removeContentLength();
+  headers.insertContentType().value().setReference(Http::Headers::get().ContentTypeValues.Grpc);
+  headers.insertEnvoyOriginalPath().value(*headers.Path());
+  headers.insertPath().value("/" + method_->service()->full_name() + "/" + method_->name());
+  headers.insertMethod().value().setReference(Http::Headers::get().MethodValues.Post);
+  headers.insertTE().value().setReference(Http::Headers::get().TEValues.Trailers);
 
   if (!config_.matchIncomingRequestInfo()) {
     decoder_callbacks_->clearRouteCache();

From c2dc9e82263c54152df58f40b4f53928ed68dd1d Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Thu, 12 Jul 2018 23:53:21 +0700
Subject: [PATCH 14/20] review: add todo skylark macro

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 api/bazel/repositories.bzl | 1 +
 1 file changed, 1 insertion(+)

diff --git a/api/bazel/repositories.bzl b/api/bazel/repositories.bzl
index da383bf5a34d..64834a1b4c4e 100644
--- a/api/bazel/repositories.bzl
+++ b/api/bazel/repositories.bzl
@@ -17,6 +17,7 @@ def api_dependencies():
         name = "googleapis",
         strip_prefix = "googleapis-" + GOOGLEAPIS_SHA,
         url = "https://github.com/googleapis/googleapis/archive/" + GOOGLEAPIS_SHA + ".tar.gz",
+        # TODO(dio): Consider writing a Skylark macro for importing Google API proto.
         build_file_content = """
 load("@com_google_protobuf//:protobuf.bzl", "cc_proto_library", "py_proto_library")
 load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")

From e9d9b1e0e1771999b1cc189455ff50b0154548cb Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Thu, 12 Jul 2018 23:53:58 +0700
Subject: [PATCH 15/20] review: clarify the use of HttpBody fields

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 .../http_filters/grpc_json_transcoder_filter.rst          | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/docs/root/configuration/http_filters/grpc_json_transcoder_filter.rst b/docs/root/configuration/http_filters/grpc_json_transcoder_filter.rst
index b6cb4f3a4b7c..471297286a12 100644
--- a/docs/root/configuration/http_filters/grpc_json_transcoder_filter.rst
+++ b/docs/root/configuration/http_filters/grpc_json_transcoder_filter.rst
@@ -67,9 +67,11 @@ Sending arbitrary content
 -------------------------
 
 By default, when transcoding occurs, gRPC-JSON encodes the message output of a gRPC service method into
-JSON and sets the response `Content-Type` header to `application/json`. To send abritrary content, a gRPC
-service method can use
+JSON and sets the HTTP response `Content-Type` header to `application/json`. To send abritrary content,
+a gRPC service method can use
 `google.api.HttpBody <https://github.com/googleapis/googleapis/blob/master/google/api/httpbody.proto>`_
 as its output message type. The implementation needs to set
 `content_type <https://github.com/googleapis/googleapis/blob/master/google/api/httpbody.proto#L68>`_
-and `data <https://github.com/googleapis/googleapis/blob/master/google/api/httpbody.proto#L71>`_ accordingly.
\ No newline at end of file
+(which sets the value of the HTTP response `Content-Type` header) and
+`data <https://github.com/googleapis/googleapis/blob/master/google/api/httpbody.proto#L71>`_
+(which sets the HTTP response body) accordingly.
\ No newline at end of file

From c0d7c87808f331828dfa2f55377b998656683c06 Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Fri, 13 Jul 2018 00:27:53 +0700
Subject: [PATCH 16/20] Add UnaryGetHttpBody integration test

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 .../grpc_json_transcoder_integration_test.cc          | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/test/extensions/filters/http/grpc_json_transcoder/grpc_json_transcoder_integration_test.cc b/test/extensions/filters/http/grpc_json_transcoder/grpc_json_transcoder_integration_test.cc
index a63ac5120f11..3ee79fc7234a 100644
--- a/test/extensions/filters/http/grpc_json_transcoder/grpc_json_transcoder_integration_test.cc
+++ b/test/extensions/filters/http/grpc_json_transcoder/grpc_json_transcoder_integration_test.cc
@@ -172,6 +172,17 @@ TEST_P(GrpcJsonTranscoderIntegrationTest, UnaryGet) {
       R"({"shelves":[{"id":"20","theme":"Children"},{"id":"1","theme":"Foo"}]})");
 }
 
+TEST_P(GrpcJsonTranscoderIntegrationTest, UnaryGetHttpBody) {
+  testTranscoding<Empty, google::api::HttpBody>(
+      Http::TestHeaderMapImpl{{":method", "GET"}, {":path", "/index"}, {":authority", "host"}},
+      "", {""}, {R"(content_type: "text/html" data: "<h1>Hello!</h1>" )"}, Status(),
+      Http::TestHeaderMapImpl{{":status", "200"},
+                              {"content-type", "text/html"},
+                              {"content-length", "15"},
+                              {"grpc-status", "0"}},
+      R"(<h1>Hello!</h1>)");
+}
+
 TEST_P(GrpcJsonTranscoderIntegrationTest, UnaryGetError) {
   testTranscoding<bookstore::GetShelfRequest, bookstore::Shelf>(
       Http::TestHeaderMapImpl{

From b45854a39a0aef6f33eaea815dc0b2511665750f Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Fri, 13 Jul 2018 00:30:09 +0700
Subject: [PATCH 17/20] Fix format

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 .../grpc_json_transcoder_integration_test.cc                  | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/test/extensions/filters/http/grpc_json_transcoder/grpc_json_transcoder_integration_test.cc b/test/extensions/filters/http/grpc_json_transcoder/grpc_json_transcoder_integration_test.cc
index 3ee79fc7234a..2417a31794de 100644
--- a/test/extensions/filters/http/grpc_json_transcoder/grpc_json_transcoder_integration_test.cc
+++ b/test/extensions/filters/http/grpc_json_transcoder/grpc_json_transcoder_integration_test.cc
@@ -174,8 +174,8 @@ TEST_P(GrpcJsonTranscoderIntegrationTest, UnaryGet) {
 
 TEST_P(GrpcJsonTranscoderIntegrationTest, UnaryGetHttpBody) {
   testTranscoding<Empty, google::api::HttpBody>(
-      Http::TestHeaderMapImpl{{":method", "GET"}, {":path", "/index"}, {":authority", "host"}},
-      "", {""}, {R"(content_type: "text/html" data: "<h1>Hello!</h1>" )"}, Status(),
+      Http::TestHeaderMapImpl{{":method", "GET"}, {":path", "/index"}, {":authority", "host"}}, "",
+      {""}, {R"(content_type: "text/html" data: "<h1>Hello!</h1>" )"}, Status(),
       Http::TestHeaderMapImpl{{":status", "200"},
                               {"content-type", "text/html"},
                               {"content-length", "15"},

From d93f57e0a9d365582d1cde1d256c528af59a21c0 Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Fri, 13 Jul 2018 02:11:24 +0700
Subject: [PATCH 18/20] Add test for splitting buffer into two encode data

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 .../json_transcoder_filter_test.cc            | 53 +++++++++++++++++--
 1 file changed, 48 insertions(+), 5 deletions(-)

diff --git a/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc b/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc
index 61cfb9e4de51..eb183b8254e2 100644
--- a/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc
+++ b/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc
@@ -561,10 +561,6 @@ TEST_F(GrpcJsonTranscoderFilterTest, TranscodingUnaryWithHttpBodyAsOutput) {
   EXPECT_EQ("/bookstore.Bookstore/GetIndex", request_headers.get_(":path"));
   EXPECT_EQ("trailers", request_headers.get_("te"));
 
-  Http::TestHeaderMapImpl continue_headers{{":status", "000"}};
-  EXPECT_EQ(Http::FilterHeadersStatus::Continue,
-            filter_.encode100ContinueHeaders(continue_headers));
-
   Http::TestHeaderMapImpl response_headers{{"content-type", "application/grpc"},
                                            {":status", "200"}};
 
@@ -581,7 +577,54 @@ TEST_F(GrpcJsonTranscoderFilterTest, TranscodingUnaryWithHttpBodyAsOutput) {
   EXPECT_EQ(Http::FilterDataStatus::StopIterationAndBuffer,
             filter_.encodeData(*response_data, false));
 
-  std::string response_html = response_data->toString();
+  const std::string response_html = response_data->toString();
+
+  EXPECT_EQ("text/html", response_headers.get_("content-type"));
+  EXPECT_EQ("<h1>Hello, world!</h1>", response_html);
+
+  Http::TestHeaderMapImpl response_trailers{{"grpc-status", "0"}, {"grpc-message", ""}};
+
+  EXPECT_EQ(Http::FilterTrailersStatus::Continue, filter_.decodeTrailers(response_trailers));
+}
+
+TEST_F(GrpcJsonTranscoderFilterTest, TranscodingUnaryWithHttpBodyAsOutputAndSplitTwoEncodeData) {
+  Http::TestHeaderMapImpl request_headers{{":method", "GET"}, {":path", "/index"}};
+
+  EXPECT_CALL(decoder_callbacks_, clearRouteCache());
+
+  EXPECT_EQ(Http::FilterHeadersStatus::Continue, filter_.decodeHeaders(request_headers, false));
+  EXPECT_EQ("application/grpc", request_headers.get_("content-type"));
+  EXPECT_EQ("/index", request_headers.get_("x-envoy-original-path"));
+  EXPECT_EQ("/bookstore.Bookstore/GetIndex", request_headers.get_(":path"));
+  EXPECT_EQ("trailers", request_headers.get_("te"));
+
+  Http::TestHeaderMapImpl response_headers{{"content-type", "application/grpc"},
+                                           {":status", "200"}};
+
+  EXPECT_EQ(Http::FilterHeadersStatus::StopIteration,
+            filter_.encodeHeaders(response_headers, false));
+  EXPECT_EQ("application/json", response_headers.get_("content-type"));
+
+  google::api::HttpBody response;
+  response.set_content_type("text/html");
+  response.set_data("<h1>Hello, world!</h1>");
+
+  auto response_data = Grpc::Common::serializeBody(response);
+  EXPECT_EQ(40, response_data->length());
+
+  // The response data buffer is splitted into two parts.
+  std::array<char, 20> out;
+  Buffer::OwnedImpl part1;
+  response_data->copyOut(0, 20, out.data());
+  part1.add(std::string(out.begin(), out.end()));
+  EXPECT_EQ(Http::FilterDataStatus::StopIterationAndBuffer, filter_.encodeData(part1, false));
+
+  Buffer::OwnedImpl part2;
+  response_data->copyOut(20, 20, out.data());
+  part2.add(std::string(out.begin(), out.end()));
+  EXPECT_EQ(Http::FilterDataStatus::StopIterationAndBuffer, filter_.encodeData(part2, false));
+
+  const std::string response_html = part2.toString();
 
   EXPECT_EQ("text/html", response_headers.get_("content-type"));
   EXPECT_EQ("<h1>Hello, world!</h1>", response_html);

From 40d9b3fe7ea8786327cb9159fc5832359448ea18 Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Fri, 13 Jul 2018 17:13:37 +0700
Subject: [PATCH 19/20] review: simplify splitting the buffer

Thanks @lizan!

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 .../json_transcoder_filter_test.cc            | 24 +++++++++----------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc b/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc
index ac82e078c28f..d3e31a2f5402 100644
--- a/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc
+++ b/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc
@@ -610,21 +610,21 @@ TEST_F(GrpcJsonTranscoderFilterTest, TranscodingUnaryWithHttpBodyAsOutputAndSpli
   response.set_data("<h1>Hello, world!</h1>");
 
   auto response_data = Grpc::Common::serializeBody(response);
-  EXPECT_EQ(40, response_data->length());
 
-  // The response data buffer is splitted into two parts.
-  std::array<char, 20> out;
-  Buffer::OwnedImpl part1;
-  response_data->copyOut(0, 20, out.data());
-  part1.add(std::string(out.begin(), out.end()));
-  EXPECT_EQ(Http::FilterDataStatus::StopIterationAndBuffer, filter_.encodeData(part1, false));
+  // Firstly, the response data buffer is splitted into two parts.
+  Buffer::OwnedImpl response_data_first_part;
+  response_data_first_part.move(*response_data, response_data->length() / 2);
 
-  Buffer::OwnedImpl part2;
-  response_data->copyOut(20, 20, out.data());
-  part2.add(std::string(out.begin(), out.end()));
-  EXPECT_EQ(Http::FilterDataStatus::StopIterationAndBuffer, filter_.encodeData(part2, false));
+  // Secondly, we send the first part of response data to the data encoding step.
+  EXPECT_EQ(Http::FilterDataStatus::StopIterationAndBuffer,
+            filter_.encodeData(response_data_first_part, false));
 
-  const std::string response_html = part2.toString();
+  // Finaly, since half of the response data buffer is moved already, here we can send the rest
+  // of it to the next data encoding step.
+  EXPECT_EQ(Http::FilterDataStatus::StopIterationAndBuffer,
+            filter_.encodeData(*response_data, false));
+
+  const std::string response_html = response_data->toString();
 
   EXPECT_EQ("text/html", response_headers.get_("content-type"));
   EXPECT_EQ("<h1>Hello, world!</h1>", response_html);

From 94037231eea7150a20b4a07b8c981ae89d1a0a60 Mon Sep 17 00:00:00 2001
From: Dhi Aurrahman <dio@rockybars.com>
Date: Fri, 13 Jul 2018 17:31:49 +0700
Subject: [PATCH 20/20] Reuse response object as expected values

Signed-off-by: Dhi Aurrahman <dio@rockybars.com>
---
 .../json_transcoder_filter_test.cc                 | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc b/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc
index d3e31a2f5402..f388588a085e 100644
--- a/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc
+++ b/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc
@@ -577,13 +577,10 @@ TEST_F(GrpcJsonTranscoderFilterTest, TranscodingUnaryWithHttpBodyAsOutput) {
   EXPECT_EQ(Http::FilterDataStatus::StopIterationAndBuffer,
             filter_.encodeData(*response_data, false));
 
-  const std::string response_html = response_data->toString();
-
-  EXPECT_EQ("text/html", response_headers.get_("content-type"));
-  EXPECT_EQ("<h1>Hello, world!</h1>", response_html);
+  EXPECT_EQ(response.content_type(), response_headers.get_("content-type"));
+  EXPECT_EQ(response.data(), response_data->toString());
 
   Http::TestHeaderMapImpl response_trailers{{"grpc-status", "0"}, {"grpc-message", ""}};
-
   EXPECT_EQ(Http::FilterTrailersStatus::Continue, filter_.decodeTrailers(response_trailers));
 }
 
@@ -624,13 +621,10 @@ TEST_F(GrpcJsonTranscoderFilterTest, TranscodingUnaryWithHttpBodyAsOutputAndSpli
   EXPECT_EQ(Http::FilterDataStatus::StopIterationAndBuffer,
             filter_.encodeData(*response_data, false));
 
-  const std::string response_html = response_data->toString();
-
-  EXPECT_EQ("text/html", response_headers.get_("content-type"));
-  EXPECT_EQ("<h1>Hello, world!</h1>", response_html);
+  EXPECT_EQ(response.content_type(), response_headers.get_("content-type"));
+  EXPECT_EQ(response.data(), response_data->toString());
 
   Http::TestHeaderMapImpl response_trailers{{"grpc-status", "0"}, {"grpc-message", ""}};
-
   EXPECT_EQ(Http::FilterTrailersStatus::Continue, filter_.decodeTrailers(response_trailers));
 }