下载protoc

protoc是protobuf文件（.proto）的编译器，使用protoc工具可以将.proto文件转换为各种编程语言对应的源码，包含数据类型定义和调用接口等。

从https://github.com/protocolbuffers/protobuf/releases下载最新安装包

• Mac protoc-version-osx-x86_64.zip
• Windows protoc-version-win64.zip

解压压缩包后将bin目录下的protoc文件移动到 $GOPATH/bin目录下，注意$GOPATH/bin需要提前添加到环境变量Path目录下。

并将include目录移动到$GOPATH目录下，用以解决如下问题：

google/protobuf/descriptor.proto: File not found.google/api/annotations.proto:20:1: Import "google/protobuf/descriptor.proto" was not found or had errors.
google/api/annotations.proto:28:8: "google.protobuf.MethodOptions" is not defined.
helloworld/helloworld.proto:10:1: Import "google/api/annotations.proto" was not found or had errors.
google/protobuf/descriptor.proto: File not found.
google/api/annotations.proto:20:1: Import "google/protobuf/descriptor.proto" was not found or had errors.
google/api/annotations.proto:28:8: "google.protobuf.MethodOptions" is not defined.
helloworld/helloworld.proto:10:1: Import "google/api/annotations.proto" was not found or had errors.

# go
export GOPATH=$HOME/go
export PATH=$PATH:$GOPATH/bin

安装 go protobuf 插件

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

测试生成文件

protoc -I=$SRC_DIR --go_out=$DST_DIR $SRC_DIR/helloworld.proto

安装gRPC

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

测试生成文件

protoc -I=$SRC_DIR --go_out=$DST_DIR --go-grpc_out=$DST_DIR $SRC_DIR/helloworld.proto

安装 grpc-gateway

go install github.com/grpc-ecosystem/grpc-gateway/v2/protoc-gen-grpc-gateway
go install github.com/grpc-ecosystem/grpc-gateway/v2/protoc-gen-openapiv2

测试生成文件

protoc -I=$SRC_DIR --grpc-gateway_out=$DST_DIR --grpc-gateway_opt logtostderr=true --grpc-gateway_opt paths=import --grpc-gateway_opt generate_unbound_methods=true $SRC_DIR/helloworld.proto