gRPC The Hard Way

gRPC clients and servers in Go using stdlib and a few helpers. Avoid https://godoc.org/google.golang.org/grpc

Motivation

gRPC in Go is often criticized for being bloated and/or too complicated. However, gRPC the protocol is relatively simple. I wanted to see how far I could get using stdlib to implement gRPC in Go.

Originally, I was going to write a reusable, alternative gRPC Go package, but I decided that would be:

• more work than I wanted to do in a simple side project
• be filled with all of my opinions

So, I decided to do straight-forward examples of simple gRPC services in Go.

Status

The code here is, hopefully, fairly straight-forward. It is not "pretty" by any means. I have not attempted to make good abstractions. I've tried to be fairly "brute force" on purpose.

The clients and servers I have written are confirmed to work with clients and servers written using the "standard" gRPC Go implementation.

Overview

The gRPC Protocol document provides the details of the gRPC protocol. A summary is that gRPC is protocol buffer encoded message over HTTP2 - and the messages are prefixed with a small amont of metadata.

Contents

Each directory listed should have a README.md with more information.

• standard contains clients and servers written using the "standard" gRPC Go implementation. These are used to test my implementations.
• services gRPC service proto definitions and generated code.
• unary contains naive implementations of a simple gRPC service.
• unary-v2 abstracts the message handling into a common library.
• server-stream is a simple streaming gRPC server implementation.
• client-stream is a simple streaming gRPC client implementation.

The clients and servers use h2c (HTTP2 over plaintext connections). They do not support TLS. In production, something like envoy handles hop-to-hop encryption for me.

Usage

These have been tested with Go 1.11.4. Clone this into your Go path like:

mkdir -p $(go env GOPATH)/src/github.com/bakins
cd $(go env GOPATH)/src/github.com/bakins
git clone https://github.com/bakins/grpc-the-hard-way.git grpc-the-hard-way
cd grpc-the-hard-way

Any commands ran in any docs assume they are being ran from the root of the repository clone.