crawlab/grpc

gRPC Setup and Compilation Guide

This guide explains how to set up and compile Protocol Buffer (protobuf) files for gRPC services in Go.

Prerequisites

Before you can compile the protobuf files, you need to install several dependencies:

1. Protocol Buffers Compiler

For Ubuntu/Debian:

sudo apt install protobuf-compiler

For macOS:

brew install protobuf

For other systems:

Download the appropriate release from the official protobuf releases page

2. Go Protobuf Plugins

Install the necessary Go plugins for protobuf compilation:

go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest

Make sure $GOPATH/bin is in your PATH:

export PATH="$PATH:$(go env GOPATH)/bin"

Project Structure

The expected project structure is:

.
├── bin/
│   └── compile.sh
├── proto/
│   └── *.proto
└── generated Go files

Compilation Script

The compile.sh script in the bin directory handles the protobuf compilation:

#!/bin/bash
if [ -L $0 ]
then
    BASE_DIR=`dirname $(readlink $0)`
else
    BASE_DIR=`dirname $0`
fi
base_path=$(cd $BASE_DIR/..; pwd)
cd $base_path && \
  protoc -I ./proto \
  --go_out=. \
  --go-grpc_out=. \
  ./proto/**/*.proto

Making the Script Executable

Give execute permissions to the compilation script:

chmod +x ./bin/compile.sh

Usage

To compile your protobuf files, run:

./bin/compile.sh

Or if the script isn't executable:

bash ./bin/compile.sh

Generated Files

The compilation will generate several types of files:

• *.pb.go: Contains the Go structs generated from your protocol buffer message definitions
• *_grpc.pb.go: Contains the gRPC service definitions and client/server code

Troubleshooting

Common Issues:

1. protoc: command not found

   • Solution: Install the protobuf compiler as described in the Prerequisites section

2. permission denied

   • Solution: Make the script executable using chmod +x ./bin/compile.sh

3. *.proto: No such file or directory

   • Solution: Ensure your .proto files are in the correct directory structure under ./proto

4. --go_out: protoc-gen-go: Plugin failed with status code 1

   • Solution: Make sure the Go protobuf plugins are properly installed and in your PATH

Maintaining Generated Code

• Don't modify the generated .pb.go and _grpc.pb.go files directly
• Always make changes to the .proto files and recompile
• Consider adding generated files to your version control system as they are needed for compilation

Additional Resources

• Protocol Buffers Documentation
• gRPC-Go Documentation
• Go Plugins for Protocol Buffers