kratos 获取 header。同时支持 http 和 grpc。

client.go

package main

import (
	"context"
	"log"

	"github.com/go-kratos/examples/helloworld/helloworld"
	"github.com/go-kratos/kratos/v2/transport/grpc"
	"github.com/go-kratos/kratos/v2/transport/http"
)

func main() {
	// 客户端
	ctx := context.Background()
	reqHttp(ctx)
	reqGrpc(ctx)
}

func reqHttp(ctx context.Context) {
	cli, _ := http.NewClient(ctx, http.WithEndpoint("127.0.0.1:8000"))

	hc := helloworld.NewGreeterHTTPClient(cli)
	reply, err := hc.SayHello(ctx, &helloworld.HelloRequest{
		Name: "http",
	})
	log.Println(reply, err)
}

func reqGrpc(ctx context.Context) {
	conn, _ := grpc.DialInsecure(ctx, grpc.WithEndpoint("127.0.0.1:9000"))

	hc := helloworld.NewGreeterClient(conn)
	reply, err := hc.SayHello(ctx, &helloworld.HelloRequest{
		Name: "grpc",
	})
	log.Println(reply, err)
}

server.go

package main

import (
	"context"
	"log"
	"log/slog"

	"github.com/go-kratos/examples/helloworld/helloworld"
	"github.com/go-kratos/kratos/v2"
	"github.com/go-kratos/kratos/v2/transport"
	"github.com/go-kratos/kratos/v2/transport/grpc"
	"github.com/go-kratos/kratos/v2/transport/http"
)

type server struct {
	helloworld.UnimplementedGreeterServer
}

func (server) SayHello(ctx context.Context, req *helloworld.HelloRequest) (*helloworld.HelloReply, error) {
	if tr, ok := transport.FromServerContext(ctx); ok { // 关键代码
		k := "User-Agent"
		ct := tr.RequestHeader().Get(k)
		slog.InfoContext(ctx, "header", slog.String(k, ct))
	}
	return &helloworld.HelloReply{Message: "Hello " + req.Name}, nil
}

func main() {
	// 服务端
	s := new(server)
	hs := http.NewServer(http.Address(":8000"))
	helloworld.RegisterGreeterHTTPServer(hs, s)

	gs := grpc.NewServer(grpc.Address(":9000"))
	helloworld.RegisterGreeterServer(gs, s)

	app := kratos.New(kratos.Server(hs, gs))
	if err := app.Run(); err != nil {
		log.Fatal(err)
	}
}