http header 转发到 grpc上下文
grpc网关可以将请求体内容转发到grpc对应消息中。那如何获取http header头中的信息，本文将介绍如何将http header转发到grpc上下文并采用拦截器，获取http header中的内容。 有些http header中的内置字段是会转发的比如Authorization，但是狠多自定义字段是转发不了的。
本文实现http header中自定义字段转发到grpc上下文并采用拦截器做个简单鉴权
代码可以参考前面几篇grpc-gateway博客
grpc-gateway入门,环境+简单案例
grpc-gateway proto定义http路由
grpc-gateway定义http路由
网关代码修改
如果要转发http header中的自定义内容，生成的网关代码需要进行修改，增加一些网关服务器选项
- runtime.WithIncomingHeaderMatcher： 请求http header 设置转发哪些到grpc上下文
- runtime.WithOutgoingHeaderMatcher: 响应后,grpc上下文转发到http头部
gateway.go
package gateway
import (
"context"
"flag"
"fmt"
"net/http"
"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
"google.golang.org/grpc"
"google.golang.org/grpc/credentials/insecure"
_ "google.golang.org/grpc/grpclog"
gw "user/proto" // Update
)
var (
// command-line options:
// gRPC server endpoint
grpcServerEndpoint = flag.String("grpc-server-endpoint", "localhost:50051", "gRPC server endpoint")
)
func Run() error {
ctx := context.Background()
ctx, cancel := context.WithCancel(ctx)
defer cancel()
// 请求时,将http header中某些字段转发到grpc上下文
inComingOpt := runtime.WithIncomingHeaderMatcher(func(s string) (string, bool) {
fmt.Println("header:" + s)
switch s {
case "Service-Authorization":
fmt.Println("Service-Authorization hit")
return "Service-Authorization", true
default:
return "", false
}
})
// 响应后,grpc上下文转发到http头部
outGoingOpt := runtime.WithOutgoingHeaderMatcher(func(s string) (string, bool) {
return "", false
})
// Register gRPC server endpoint
// Note: Make sure the gRPC server is running properly and accessible
mux := runtime.NewServeMux(inComingOpt, outGoingOpt)
//添加文件上传处理函数
mux.HandlePath("POST", "/upload", uploadHandler)
opts := []grpc.DialOption{grpc.WithTransportCredentials(insecure.NewCredentials())}
err := gw.RegisterUserHandlerFromEndpoint(ctx, mux, *grpcServerEndpoint, opts)
if err != nil {
return err
}
// Start HTTP server (and proxy calls to gRPC server endpoint)
return http.ListenAndServe(":8081", mux)
}
文件上传接口修改，因为这是自定义的网关路由接口，需要自己将Header中的字段转发到grpc中
upload.go
package gateway
import (
"context"
"fmt"
"github.com/golang/protobuf/jsonpb"
"google.golang.org/grpc"
"google.golang.org/grpc/credentials/insecure"
"google.golang.org/grpc/metadata"
"io"
"net/http"
"user/proto"
)
func uploadHandler(w http.ResponseWriter, r *http.Request, pathParams map[string]string) {
// 先从request解析文件
err := r.ParseForm()
if err != nil {
http.Error(w, fmt.Sprintf("上传失败:%s", err.Error()), http.StatusInternalServerError)
}
f, header, err :=r.FormFile("attachment")
if err != nil {
http.Error(w, fmt.Sprintf("上传失败:%s", err.Error()), http.StatusInternalServerError)
}
defer f.Close()
// 访问grpc server端, 实际生产用连接池
conn, err := grpc.Dial(*grpcServerEndpoint, grpc.WithTransportCredentials(insecure.NewCredentials()))
if err != nil {
http.Error(w, fmt.Sprintf("上传失败:%s", err.Error()), http.StatusInternalServerError)
}
defer conn.Close()
c := proto.NewUserClient(conn)
ctx := context.Background()
ctx = metadata.NewOutgoingContext(ctx, metadata.New(map[string]string{
"file_name":header.Filename,
"service-authorization":r.Header.Get("Service-Authorization"),
}))
stream, err := c.Upload(ctx)
if err != nil {
http.Error(w, fmt.Sprintf("上传失败:%s", err.Error()), http.StatusInternalServerError)
}
// 读文件流 转发给grpc
buf := make([]byte, 512)
for {
n, err := f.Read(buf)
if err != nil && err != io.EOF{
http.Error(w, fmt.Sprintf("上传失败:%s", err.Error()), http.StatusInternalServerError)
}
if n == 0 {
break
}
stream.Send(&proto.UploadRequest{
Content: buf[:n],
Size: int64(n),
})
}
res, err := stream.CloseAndRecv()
if err != nil {
http.Error(w, fmt.Sprintf("上传失败:%s", err.Error()), http.StatusInternalServerError)
}
m := jsonpb.Marshaler{}
str, _ := m.MarshalToString(res)
if err != nil {
http.Error(w, fmt.Sprintf("上传失败:%s", err.Error()), http.StatusInternalServerError)
}
w.Header().Add("Content-Type", "application/json")
fmt.Fprintf(w, str)
}
grpc服务代码修改
拦截器，从上下文中获取元数据进行业务操作即可
interceptor.go
package server
import (
"context"
"errors"
"fmt"
"google.golang.org/grpc"
"google.golang.org/grpc/metadata"
"strings"
)
func UnaryInterceptor(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
err = auth(ctx)
if err != nil {
return nil, err
}
return handler(ctx, req)
}
func StreamInterceptor(srv interface{}, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
err := auth(ss.Context())
if err != nil {
return err
}
return handler(srv, ss)
}
func auth(ctx context.Context) error {
md, ok := metadata.FromIncomingContext(ctx)
fmt.Println("meta:", md)
// 实际应用中，返回前端提示需模糊化,详细错误可以打印日志
if !ok {
return errors.New("获取元数据失败，身份校验失败")
}
// 转发过来都是小写
authorization := md["service-authorization"]
if len(authorization) < 1 {
return errors.New("获取身份令牌失败，身份校验失败")
}
token := strings.TrimPrefix(authorization[0], "Bearer ")
if token != bearerToken {
return errors.New("身份令牌对比失败，身份校验失败")
}
return nil
}
// 测试用
var bearerToken = "sdfdlsdhgeiasdxzasqqqy2ybfhhu2gyvb"
并将拦截器注册到grpc服务中文章来源：https://www.toymoban.com/news/detail-717402.html
s := grpc.NewServer(grpc.UnaryInterceptor(server.UnaryInterceptor), grpc.StreamInterceptor(server.StreamInterceptor))
重点还是网关代码修改，增加转发header的逻辑。文章来源地址https://www.toymoban.com/news/detail-717402.html
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