Revert "Metadata tutorial"

examples/BUILD

@@ -51,18 +51,3 @@ cc_binary(
     defines = ["BAZEL_BUILD"],
     deps = [":helloworld", "//:grpc++"],
 )
-
-cc_binary(
-    name = "metadata_client",
-    srcs = ["cpp/metadata/greeter_client.cc"],
-    defines = ["BAZEL_BUILD"],
-    deps = [":helloworld", "//:grpc++"],
-)
-
-cc_binary(
-    name = "metadata_server",
-    srcs = ["cpp/metadata/greeter_server.cc"],
-    defines = ["BAZEL_BUILD"],
-    deps = [":helloworld", "//:grpc++"],
-)
-

examples/cpp/metadata/Makefile

@@ -1,96 +0,0 @@
-#
-# Copyright 2018 gRPC authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-#
- HOST_SYSTEM = $(shell uname | cut -f 1 -d_)
-SYSTEM ?= $(HOST_SYSTEM)
-CXX = g++
-CPPFLAGS += `pkg-config --cflags protobuf grpc`
-CXXFLAGS += -std=c++11
-ifeq ($(SYSTEM),Darwin)
-LDFLAGS += -L/usr/local/lib `pkg-config --libs protobuf grpc++ grpc`\
-           -lgrpc++_reflection\
-           -ldl
-else
-LDFLAGS += -L/usr/local/lib `pkg-config --libs protobuf grpc++ grpc`\
-           -Wl,--no-as-needed -lgrpc++_reflection -Wl,--as-needed\
-           -ldl
-endif
-PROTOC = protoc
-GRPC_CPP_PLUGIN = grpc_cpp_plugin
-GRPC_CPP_PLUGIN_PATH ?= `which $(GRPC_CPP_PLUGIN)`
- PROTOS_PATH = ../../protos
- vpath %.proto $(PROTOS_PATH)
- all: system-check greeter_client greeter_server
- greeter_client: helloworld.pb.o helloworld.grpc.pb.o greeter_client.o
-	$(CXX) $^ $(LDFLAGS) -o $@
- greeter_server: helloworld.pb.o helloworld.grpc.pb.o greeter_server.o
-	$(CXX) $^ $(LDFLAGS) -o $@
- .PRECIOUS: %.grpc.pb.cc
-%.grpc.pb.cc: %.proto
-	$(PROTOC) -I $(PROTOS_PATH) --grpc_out=. --plugin=protoc-gen-grpc=$(GRPC_CPP_PLUGIN_PATH) $<
- .PRECIOUS: %.pb.cc
-%.pb.cc: %.proto
-	$(PROTOC) -I $(PROTOS_PATH) --cpp_out=. $<
- clean:
-	rm -f *.o *.pb.cc *.pb.h greeter_client greeter_server
- # The following is to test your system and ensure a smoother experience.
-# They are by no means necessary to actually compile a grpc-enabled software.
- PROTOC_CMD = which $(PROTOC)
-PROTOC_CHECK_CMD = $(PROTOC) --version | grep -q libprotoc.3
-PLUGIN_CHECK_CMD = which $(GRPC_CPP_PLUGIN)
-HAS_PROTOC = $(shell $(PROTOC_CMD) > /dev/null && echo true || echo false)
-ifeq ($(HAS_PROTOC),true)
-HAS_VALID_PROTOC = $(shell $(PROTOC_CHECK_CMD) 2> /dev/null && echo true || echo false)
-endif
-HAS_PLUGIN = $(shell $(PLUGIN_CHECK_CMD) > /dev/null && echo true || echo false)
- SYSTEM_OK = false
-ifeq ($(HAS_VALID_PROTOC),true)
-ifeq ($(HAS_PLUGIN),true)
-SYSTEM_OK = true
-endif
-endif
- system-check:
-ifneq ($(HAS_VALID_PROTOC),true)
-	@echo " DEPENDENCY ERROR"
-	@echo
-	@echo "You don't have protoc 3.0.0 installed in your path."
-	@echo "Please install Google protocol buffers 3.0.0 and its compiler."
-	@echo "You can find it here:"
-	@echo
-	@echo "   https://github.com/google/protobuf/releases/tag/v3.0.0"
-	@echo
-	@echo "Here is what I get when trying to evaluate your version of protoc:"
-	@echo
-	-$(PROTOC) --version
-	@echo
-	@echo
-endif
-ifneq ($(HAS_PLUGIN),true)
-	@echo " DEPENDENCY ERROR"
-	@echo
-	@echo "You don't have the grpc c++ protobuf plugin installed in your path."
-	@echo "Please install grpc. You can find it here:"
-	@echo
-	@echo "   https://github.com/grpc/grpc"
-	@echo
-	@echo "Here is what I get when trying to detect if you have the plugin:"
-	@echo
-	-which $(GRPC_CPP_PLUGIN)
-	@echo
-	@echo
-endif
-ifneq ($(SYSTEM_OK),true)
-	@false
-endif

examples/cpp/metadata/README.md

@@ -1,66 +0,0 @@
-# Metadata Example
-
-## Overview
-
-This example shows you how to add custom headers on the client and server and 
-how to access them.
-
-Custom metadata must follow the "Custom-Metadata" format listed in 
-https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md, with the 
-exception of binary headers, which don't have to be base64 encoded.
-
-### Get the tutorial source code
- The example code for this and our other examples lives in the `examples` directory. Clone this repository to your local machine by running the following command:
- ```sh
-$ git clone -b $(curl -L https://grpc.io/release) https://github.com/grpc/grpc
-```
- Change your current directory to examples/cpp/metadata
- ```sh
-$ cd examples/cpp/metadata
-```
-
-### Generating gRPC code
- To generate the client and server side interfaces:
- ```sh
-$ make helloworld.grpc.pb.cc helloworld.pb.cc
-```
-Which internally invokes the proto-compiler as:
- ```sh
-$ protoc -I ../../protos/ --grpc_out=. --plugin=protoc-gen-grpc=grpc_cpp_plugin ../../protos/helloworld.proto
-$ protoc -I ../../protos/ --cpp_out=. ../../protos/helloworld.proto
-```
-### Try it!
-Build client and server:
-
-```sh
-$ make
-```
-
-Run the server, which will listen on port 50051:
-
-```sh
-$ ./greeter_server
-```
-
-Run the client (in a different terminal):
-
-```sh
-$ ./greeter_client
-```
-
-If things go smoothly, you will see in the client terminal:
-
-"Client received initial metadata from server: initial metadata value"
-"Client received trailing metadata from server: trailing metadata value"
-"Client received message: Hello World"
-
-
-And in the server terminal:
-
-"Header key: custom-bin , value: 01234567"
-"Header key: custom-header , value: Custom Value"
-"Header key: user-agent , value: grpc-c++/1.16.0-dev grpc-c/6.0.0-dev (linux; chttp2; gao)"
-
-We did not add the user-agent metadata as a custom header. This shows how 
-the gRPC framework adds some headers under the hood that may show up in the 
-metadata map.

examples/cpp/metadata/greeter_client.cc

@@ -1,95 +0,0 @@
-/*
- *
- * Copyright 2015 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-#include <iostream>
-#include <memory>
-#include <string>
-
-#include <grpcpp/grpcpp.h>
-
-#ifdef BAZEL_BUILD
-#include "examples/protos/helloworld.grpc.pb.h"
-#else
-#include "helloworld.grpc.pb.h"
-#endif
-
-using grpc::Channel;
-using grpc::ClientContext;
-using grpc::Status;
-using helloworld::HelloRequest;
-using helloworld::HelloReply;
-using helloworld::Greeter;
-
-class CustomHeaderClient {
- public:
-  CustomHeaderClient(std::shared_ptr<Channel> channel)
-      : stub_(Greeter::NewStub(channel)) {}
-
-  // Assembles the client's payload, sends it and presents the response back
-  // from the server.
-  std::string SayHello(const std::string& user) {
-    // Data we are sending to the server.
-    HelloRequest request;
-    request.set_name(user);
-
-    // Container for the data we expect from the server.
-    HelloReply reply;
-
-    // Context for the client. It could be used to convey extra information to
-    // the server and/or tweak certain RPC behaviors.
-    ClientContext context;
-
-    // Setting custom metadata to be sent to the server
-    context.AddMetadata("custom-header", "Custom Value");
-
-    // Setting custom binary metadata 
-    char bytes[8] = {'\0', '\1', '\2', '\3',
-                     '\4', '\5', '\6', '\7'};
-    context.AddMetadata("custom-bin", grpc::string(bytes, 8));
-
-    // The actual RPC.
-    Status status = stub_->SayHello(&context, request, &reply);
-
-    // Act upon its status.
-    if (status.ok()) {
-      std::cout << "Client received initial metadata from server: " << context.GetServerInitialMetadata().find("custom-server-metadata")->second << std::endl;
-      std::cout << "Client received trailing metadata from server: " << context.GetServerTrailingMetadata().find("custom-trailing-metadata")->second << std::endl;
-      return reply.message();
-    } else {
-      std::cout << status.error_code() << ": " << status.error_message()
-                << std::endl;
-      return "RPC failed";
-    }
-  }
-
- private:
-  std::unique_ptr<Greeter::Stub> stub_;
-};
-
-int main(int argc, char** argv) {
-  // Instantiate the client. It requires a channel, out of which the actual RPCs
-  // are created. This channel models a connection to an endpoint (in this case,
-  // localhost at port 50051). We indicate that the channel isn't authenticated
-  // (use of InsecureChannelCredentials()).
-  CustomHeaderClient greeter(grpc::CreateChannel(
-      "localhost:50051", grpc::InsecureChannelCredentials()));
-  std::string user("world");
-  std::string reply = greeter.SayHello(user);
-  std::cout << "Client received message: " << reply << std::endl;
-  return 0;
-}

examples/cpp/metadata/greeter_server.cc

@@ -1,94 +0,0 @@
-/*
- *
- * Copyright 2015 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-#include <iostream>
-#include <memory>
-#include <string>
-
-#include <grpcpp/grpcpp.h>
-
-#ifdef BAZEL_BUILD
-#include "examples/protos/helloworld.grpc.pb.h"
-#else
-#include "helloworld.grpc.pb.h"
-#endif
-
-using grpc::Server;
-using grpc::ServerBuilder;
-using grpc::ServerContext;
-using grpc::Status;
-using helloworld::HelloRequest;
-using helloworld::HelloReply;
-using helloworld::Greeter;
-
-// Logic and data behind the server's behavior.
-class GreeterServiceImpl final : public Greeter::Service {
-  Status SayHello(ServerContext* context, const HelloRequest* request,
-                  HelloReply* reply) override {
-    std::string prefix("Hello ");
-
-    // Get the client's initial metadata
-    std::cout << "Client metadata: " << std::endl;
-    const std::multimap<grpc::string_ref, grpc::string_ref> metadata = context->client_metadata();
-    for (auto iter = metadata.begin(); iter != metadata.end(); ++iter) {
-      std::cout << "Header key: " << iter->first << ", value: ";
-      // Check for binary value
-      size_t isbin = iter->first.find("-bin");
-      if ((isbin != std::string::npos) && (isbin + 4 == iter->first.size())) {
-        std::cout <<  std::hex;
-        for (auto c : iter->second) {
-          std::cout << static_cast<unsigned int>(c);
-        }
-        std::cout <<  std::dec;
-      } else {
-        std::cout << iter->second;
-      }
-      std::cout << std::endl;
-    }
-
-    context->AddInitialMetadata("custom-server-metadata", "initial metadata value");
-    context->AddTrailingMetadata("custom-trailing-metadata", "trailing metadata value");
-    reply->set_message(prefix + request->name());
-    return Status::OK;
-  }
-};
-
-void RunServer() {
-  std::string server_address("0.0.0.0:50051");
-  GreeterServiceImpl service;
-
-  ServerBuilder builder;
-  // Listen on the given address without any authentication mechanism.
-  builder.AddListeningPort(server_address, grpc::InsecureServerCredentials());
-  // Register "service" as the instance through which we'll communicate with
-  // clients. In this case it corresponds to an *synchronous* service.
-  builder.RegisterService(&service);
-  // Finally assemble the server.
-  std::unique_ptr<Server> server(builder.BuildAndStart());
-  std::cout << "Server listening on " << server_address << std::endl;
-
-  // Wait for the server to shutdown. Note that some other thread must be
-  // responsible for shutting down the server for this call to ever return.
-  server->Wait();
-}
-
-int main(int argc, char** argv) {
-  RunServer();
-
-  return 0;
-}