hello-grpc

Demos of my talk A gentle introduction to gRPC.

The slides are here.

Building

In theory, you can build the sources on any supported platforms.

For simplicity, I have assembled this demo on Visual Studio 2019, relying on vcpkg for obtaining and building all the library dependencies. So, the first thing you need to do is to install vcpkg and then get the required libraries.

I didn't use vcpkg manifest feature so let me tell you which libraries you have to install.

As you might image, all the projects need grpc:

vcpkg install grpc --triplet x64-windows

For the project message-broker, I have made use of a few extra libraries:

vcpkg install sobjectizer --triplet x64-windows
vcpkg install spdlog --triplet x64-windows

For hello-test I have installed:

vcpkg install gtest --triplet x64-windows

Finally, remember that message-broker-client is a .Net Core project relying on NuGet official sources.

Project settings

First of all, since I have integrated vcpkg, all the include files and libraries are automatically available in my demo projects. Thus, if you are not relying on this feature, you have to explicitly link the libraries and also add additional references to the include files.

A few notes on the projects.

0. Clearly, enable vcpkg on all the projects:

   • Open any project properties
   • navigate to vcpkg
   • then set Yes on Use Vcpkg

1. Since I am an insane pirate 🏴‍☠️, I have turned the latest features on:

   • Open any project properties
   • navigate to C/C++
   • then to Language
   • finally to C++ Language Standard and set the last option /std:c++latest.

2. grpc has some compilation issues with C++17 so I have just turned off some annoying warning messages by adding _SILENCE_ALL_CXX17_DEPRECATION_WARNINGS to the Preprocessor Definitions:

   • Open any project properties
   • navigate to C/C++
   • finally to Preprocessor and add _SILENCE_ALL_CXX17_DEPRECATION_WARNINGS

3. Since grpc depends on protobuf that is linked dynamically, some warnings might be emitted due to standard types crossing the dll boundaries. For this reason, I have turned them all off:

   • Open any project properties
   • navigate to C/C++
   • then to Command Line
   • finally to Additional Options and add /wd4251

4. grpc needs Winsock2 library and this is not linked automatically. I usually do not pollute the source code with non-standard directives like #pragma comment (lib, "Ws2_32.lib") so I have added the library by hand on the linker options:

   • Open any project properties
   • navigate to Linker
   • then to Input
   • finally to Additional Dependencies and add Ws2_32.lib (do not remove %(AdditionalDependencies))

Have fun!

gRPCurl usage examples

grpcurl is a command-line tool that lets you interact with gRPC servers. It's basically curl for gRPC servers.

Download the latest release from here.

All the following examples use grpc reflection (but grpcurl supports also compiled protoset files and proto sources).

• List all the services exposed at a certain endpoint:

grpcurl.exe -plaintext localhost:50051 list

• List all the rpc methods of a certain service:

grpcurl.exe -plaintext localhost:50051 list MessageBroker

• Describe a certain rpc method:

grpcurl.exe -plaintext localhost:50051 describe MessageBroker.Send

• Describe the method's request parameter:

grpcurl.exe -plaintext localhost:50051 describe SendRequest

• Describe the type of a message:

grpcurl.exe -plaintext localhost:50051 describe Message

• Call a certain rpc method (on Windows we need to escape " and introduce json with " instead of '):

grpcurl --plaintext -d "{\"messages\": [ {\"topic\" : \"Channel1\", \"content\" : \"hello\" } ]}" localhost:50051 MessageBroker/Send

ghz usage examples

ghz is a command line utility and Go package for load testing and benchmarking gRPC services.

Download the latest release from here.

All the following examples use grpc reflection (but ghz supports also proto sources).

• Simple unary call test:

ghz --insecure --call MessageBroker/Send -d "{\"messages\": [ {\"topic\" : \"Channel1\", \"content\" : \"hello\" } ]}" localhost:50051

• Simple unary call with 20 threads:

ghz --insecure --call MessageBroker/Send -d "{\"messages\": [ {\"topic\" : \"Channel1\", \"content\" : \"hello\" } ]}" -c 20 localhost:50051