grpc優點不再多敘述，但如何對外提供Restful接口的，而有不希望重複開發相同的功能可以使用grpc-gateway將grpc轉換爲對外的Restful API。
安裝
go get -u github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway
go get -u github.com/micro/protobuf/{proto,protoc-gen-go}
如果只是使用，其實處理起來很簡單在原有grpc的.proto文件中添加相應的import文件和http配置聲明即可。
import文件
import "google/api/annotations.proto";
http配置聲明
service Bookinfo {
// get book information
rpc Getall (GetallRequest) returns (GetallResponse) {
option (google.api.http) = {
post: "/bookinfo/getall"
body: "*"
};
};
}
大概說明
bookinfo.proto文件
syntax = "proto3";
package bookinfo;
import "google/api/annotations.proto";
option go_package = "bookinfopb";
// The book service makes it possible to get or set book's detail information
service Bookinfo {
// get book information
rpc Getall (GetallRequest) returns (GetallResponse) {
option (google.api.http) = {
post: "/bookinfo/getall"
body: "*"
};
};
// add books information
rpc Add (AddRequest) returns (AddResponse){
option (google.api.http) = {
post: "/bookinfo/add"
body: "*"
};
};
}
message GetallRequest {
// ID of user
string userid = 1;
}
message GetallResponse {
// Book info list
repeated BookInfo bookinfolist = 1;
}
message BookInfo {
// Name of book
string book_name = 1;
// Author
string author = 2;
// Chapters name
repeated ChapterInfo chapters_info = 3;
}
message ChapterInfo {
// Chapter number
sint32 chapter_num = 1;
// Chapter name
string chapter_name = 2;
// Words cound
sint32 words_count = 3;
}
message AddRequest {
// Books information
repeated BookInfo books_info = 1;
}
message AddResponse {
repeated sint32 field = 1;
}
定義請求接口名，參數和返回結果
Getall接口的參數是string類型的userid。返回結果是書籍詳情（BookInfo）的數組(通過repeated標識)
生成grpc服務的stub文件
protoc -I/usr/local/include -I. \
-I$(GOPATH)/src \
-I$(GOPATH)/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis \
--go_out=plugins=grpc:. bookinfo-srv/proto/bookinfo/bookinfo.proto
生成bookinfo.pb.go文件
生成grpc-gateway的stub文件
protoc -I/usr/local/include -I. \
-I $(GOPATH)/src \
-I $(GOPATH)/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis \
--grpc-gateway_out=logtostderr=true:. bookinfo-srv/proto/bookinfo/bookinfo.proto
生成bookinfo.pb.gw.go文件
grpc功能的實現
-
service.go
package main
import (
pb "grpcT1/bookinfo-srv/proto/bookinfo" bkinfoprocess "grpcT1/bookinfo-srv/process" "net" "log" "google.golang.org/grpc")
const (PORT = ":50051")
func main() {
listener, err := net.Listen("tcp", PORT) if err != nil { log.Fatalf("failed to listen: %v", err) } log.Printf("listen on: %s\n", PORT) server := grpc.NewServer() pb.RegisterBookinfoServer(server, bkinfoprocess.NewBookinfo()) if err := server.Serve(listener); err != nil { log.Fatalf("failed to serve: %v", err) }}
其中RegisterBookinfoServer方法是在bookinfo.pb.go中定義和實現的
-
process/bookinfo.go 定義的接口方法的具體邏輯實現
package bookinfoprocess
import (
bookinfo "grpcT1/bookinfo-srv/proto/bookinfo" "context" "fmt")
type bookinfosrvc struct {}
func NewBookinfo() bookinfo.BookinfoServer {
return &bookinfosrvc{}}
func (s bookinfosrvc) Getall(ctx context.Context, p bookinfo.GetallRequest) (*bookinfo.GetallResponse, error) {
res := &bookinfo.GetallResponse{} fmt.Println("bookinfo.getall") cpsInfo := make([]*bookinfo.ChapterInfo,4) cpsInfo[0] = &bookinfo.ChapterInfo{ChapterNum:1, ChapterName:"序言", WordsCount:3259} cpsInfo[1] = &bookinfo.ChapterInfo{ChapterNum:2, ChapterName:"布爾", WordsCount:4559} cpsInfo[2] = &bookinfo.ChapterInfo{ChapterNum:3, ChapterName:"字符", WordsCount:7559} cpsInfo[3] = &bookinfo.ChapterInfo{ChapterNum:4, ChapterName:"函數", WordsCount:7859} bkInfo := &bookinfo.BookInfo{BookName:"Ugly language", Author:"Bill", ChaptersInfo:cpsInfo} res.Bookinfolist = append(res.Bookinfolist, bkInfo) return res, nil}
func (s bookinfosrvc) Add(ctx context.Context, p bookinfo.AddRequest) (*bookinfo.AddResponse, error) {
return nil, nil}
gateway方式對外提供http接口
-
gateway/main.go
package main
import (
"flag" "net/http" "github.com/golang/glog" "golang.org/x/net/context" "github.com/grpc-ecosystem/grpc-gateway/runtime" "google.golang.org/grpc" gw "grpcT1/bookinfo-srv/proto/bookinfo")
var (
echoEndpoint = flag.String("getall_endpoint", "rpcserver:50051", "endpoint of BookInfoService"))
func run() error {
ctx := context.Background() ctx, cancel := context.WithCancel(ctx) defer cancel() mux := runtime.NewServeMux() opts := []grpc.DialOption{grpc.WithInsecure()} err := gw.RegisterBookinfoHandlerFromEndpoint(ctx, mux, *echoEndpoint, opts) if err != nil { return err } return http.ListenAndServe(":8080", mux)}
func main() {
flag.Parse() defer glog.Flush() if err := run(); err != nil { glog.Fatal(err) }}
其中RegisterBookinfoHandlerFromEndpoint方法在bookinfo.pb.gw.go中定義和實現
grpc請求
-
client/main.go
package main
import (
pb "grpcT1/bookinfo-srv/proto/bookinfo" "google.golang.org/grpc" "log" "context")
const (
ADDRESS = "rpcserver:50051")
func main() {
// 連接到 gRPC 服務器 conn, err := grpc.Dial(ADDRESS, grpc.WithInsecure()) if err != nil { log.Fatalf("connect error: %v", err) } defer conn.Close() // 初始化 gRPC 客戶端 client := pb.NewBookinfoClient(conn) resp, err := client.Getall(context.Background(), &pb.GetallRequest{Userid:"tt"}) if err != nil { log.Fatalf("Getall error: %v", err) } length := len(resp.Bookinfolist) for i:=0;i<length;i++ { log.Printf("bookName:%s\n",resp.Bookinfolist[i].BookName) log.Printf("author:%s\n", resp.Bookinfolist[i].Author) chaptersCount := len(resp.Bookinfolist[i].ChaptersInfo) for j:=0;j<chaptersCount;j++ { log.Printf("---Chapter.Num:%d\n", resp.Bookinfolist[i].ChaptersInfo[j].ChapterNum) log.Printf("---Chapter.Name:%s\n", resp.Bookinfolist[i].ChaptersInfo[j].ChapterName) log.Printf("---Chapter.WordsCount:%d\n", resp.Bookinfolist[i].ChaptersInfo[j].WordsCount) log.Println("") } }}
client調用grpc接口的實現。NewBookinfoClient方法在bookinfo.pb.go中定義和實現
http請求測試
curl -X POST -k http://localhost:8080/bookinfo/getall -d '{"userid":"tt"}'
詳細代碼可以從這取得 https://github.com/BinWang-sh...
根目錄下有makefile可生成stub和docker鏡像
Docker目錄下有docker-compose文件執行docker-compose up可以直接run