//Backend

package main
  
import (
        "flag"
        "fmt"
//      "log"

        "github.com/valyala/fasthttp"
        "github.com/akutz/memconn"
)

var (
//      addr     = flag.String("addr", ":8080", "TCP address to listen to")
        compress = flag.Bool("compress", false, "Whether to enable transparent response compression")
)

func main() {
        flag.Parse()

        h := requestHandler
        if *compress {
                h = fasthttp.CompressHandler(h)
        }

        lis, err := memconn.Listen("memu", "MYTEST")
        if err != nil {
                fmt.Printf("err = %v\n",err)
        }

        fasthttp.Serve(lis, h)
}

func requestHandler(ctx *fasthttp.RequestCtx) {
        fmt.Fprintf(ctx, "Hello, world!\n\n")

        fmt.Fprintf(ctx, "Request method is %q\n", ctx.Method())
        fmt.Fprintf(ctx, "RequestURI is %q\n", ctx.RequestURI())
        fmt.Fprintf(ctx, "Requested path is %q\n", ctx.Path())
        fmt.Fprintf(ctx, "Host is %q\n", ctx.Host())
        fmt.Fprintf(ctx, "Query string is %q\n", ctx.QueryArgs())
        fmt.Fprintf(ctx, "User-Agent is %q\n", ctx.UserAgent())
        fmt.Fprintf(ctx, "Connection has been established at %s\n", ctx.ConnTime())
        fmt.Fprintf(ctx, "Request has been started at %s\n", ctx.Time())
        fmt.Fprintf(ctx, "Serial request number for the current connection is %d\n", ctx.ConnRequestNum())
        fmt.Fprintf(ctx, "Your ip is %q\n\n", ctx.RemoteIP())

        fmt.Fprintf(ctx, "Raw request is:\n---CUT---\n%s\n---CUT---", &ctx.Request)

        ctx.SetContentType("text/plain; charset=utf8")

        // Set arbitrary headers
        ctx.Response.Header.Set("X-My-Header", "my-header-value")

        // Set cookies
        var c fasthttp.Cookie
        c.SetKey("cookie-name")
        c.SetValue("cookie-value")
        ctx.Response.Header.SetCookie(&c)
}

package main

import (
        "github.com/valyala/fasthttp"
        "github.com/akutz/memconn"
        "log"
)

/*
var proxyClient = &fasthttp.HostClient{
        Addr: "upstream.host:port",
        // set other options here if required - most notably timeouts.
}
*/

var (


        proxyClient = &fasthttp.HostClient{
                Addr: "/tmp/http.socket", //?????????
                Dial: func(addr string) (net.Conn, error) {
                        return net.Dial("unix", addr)
                        //return memconn.Dial("memu", "MYTEST")
                },
                //      }
                //      proxyClient = &fasthttp.HostClient{
                //              Addr: "127.0.0.1:87",
                //              Addr: xServerClient,
                //              MaxConns: 16777216,
                MaxIdleConnDuration: 30 * time.Second,
                ReadBufferSize:  64 * 1024,
                WriteBufferSize: 64 * 1024,
                ReadTimeout: 30 * time.Second,
                WriteTimeout: 30 * time.Second,
        }


)

func reverseProxyHandler(ctx *fasthttp.RequestCtx) {
        req := &ctx.Request
        resp := &ctx.Response
        prepareRequest(req)
        if err := proxyClient.Do(req, resp); err != nil {
                ctx.Logger().Printf("error when proxying the request: %s", err)
        }
        postprocessResponse(resp)
}

func prepareRequest(req *fasthttp.Request) {
        // do not proxy "Connection" header.
        req.Header.Del("Connection")
        // strip other unneeded headers.

        // alter other request params before sending them to upstream host
}

func postprocessResponse(resp *fasthttp.Response) {
        // do not proxy "Connection" header
        resp.Header.Del("Connection")

        // strip other unneeded headers

        // alter other response data if needed
}

func main() {

        if err := fasthttp.ListenAndServe(":80", reverseProxyHandler); err != nil {
                log.Fatalf("error in fasthttp server: %s", err)
        }
} 

Hello, world.panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x10e8f62]

goroutine 1 [running]:
github.com/akutz/memconn.(*Listener).Close(0x0, 0x0, 0x7)
        /.go/src/github.com/akutz/memconn/memconn_listener.go:95 +0x22
main.main()
        /temp/memconn.go:48 +0x2c7
exit status 2