go net/rpc graceful shutdown

main.go

package main

import (
        "context"
        "flag"
        "log"
        "net/http"
	"net/rpc"
        "os"
        "os/signal"
        "strconv"
        "time"

        "github.com/boltdb/bolt"
        "github.com/helinwang/kv"
)

func main() {
        path := flag.String("path", "", "path to db file, will be created if not exists")
        port := flag.Int("port", 8080, "service port")
        ip := flag.String("ip", "0.0.0.0", "service ip")
        flag.Parse()

        db, err := bolt.Open(*path, 0666, nil)
        if err != nil {
                panic(err)
        }

        s := &kv.Service{DB: db}
        rpcSrv := rpc.NewServer()
        err = rpcSrv.Register(s)
        if err != nil {
                panic(err)
        }

        srv := &http.Server{
                Addr:    *ip + ":" + strconv.Itoa(*port),
                Handler: rpcSrv,
        }

        stop := make(chan os.Signal, 1)
        signal.Notify(stop, os.Interrupt)

        go func() {
                err := srv.ListenAndServe()
                if err != nil {
                        log.Fatal("listen error:", err)
                }
        }()

        <-stop
        ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
        srv.Shutdown(ctx)
        cancel()
}