ginx/main.go

package main

import (
	"encoding/json"
	"net/http"
	"net/url"
	"net/http/httputil"
	"log"
	"flag"
	"fmt"
	"io/ioutil"
	"os"
)

type Config struct {
	Server string `json:"server"`
	Upstream []string `json:"upstream"`
}


var loadBalancer = NewWeightedRR(RR_NGINX)

type handle struct {
    addrs []string
}

func (this *handle) ServeHTTP(w http.ResponseWriter, r *http.Request) {
    addr := loadBalancer.Next().(string)
    remote, err := url.Parse("http://" + addr)
    if err != nil {
        panic(err)
    }
    proxy := httputil.NewSingleHostReverseProxy(remote)
    proxy.ServeHTTP(w, r)
}

func startServer(server string, upstream []string) {
    //被代理的服务器host和port
    h := &handle{}
    h.addrs = upstream

    w := 1
    for _, e := range h.addrs {
        loadBalancer.Add(e, w)
        w++
    }
    err := http.ListenAndServe(server, h)
    if err != nil {
        log.Fatalln("ListenAndServe: ", err)
    }
}

func main() {
	server := flag.String("server", ":9999", "Your server")
	upstream := flag.String("upstream", "127.0.0.1:3000", "upstream server")
	flag.Parse()
	fmt.Println(*server)
	fmt.Println(*upstream)

	file, err := ioutil.ReadFile("./config.json")
	if err != nil {
		fmt.Printf("File error: %v\n", err)
		os.Exit(1)
	}

	var config Config
	json.Unmarshal(file, &config)

    // startServer(*server, *upstream)
    startServer(config.Server, config.Upstream)
}