Revert "Metadata tutorial"

6 years ago · 951254151b
parent 21940df57e
commit 951254151b
5 changed files with 0 additions and 366 deletions
--- a/examples/BUILD
+++ b/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++"],
 )
--- a/examples/cpp/metadata/Makefile
+++ b/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
--- a/examples/cpp/metadata/README.md
+++ b/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.
--- a/examples/cpp/metadata/greeter_client.cc
+++ b/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;
 }
--- a/examples/cpp/metadata/greeter_server.cc
+++ b/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;
 }