A web server that runs out of inetd

stdinweb.go

package main

import (
	"errors"
	"fmt"
	"net"
	"net/http"
	"os"
	"time"
)

type StdioListener bool
type StdioConn bool

var stategen = make(chan bool)

// Listener implementation

func (sl *StdioListener) Accept() (net.Conn, error) {
	// I can only accept once, but this is called in a relatively
	// tight loop.  I'm driving the two states with a simple
	// boolean channel.  The first accept is a real connection.
	// The next one blocks until that connection is done at which
	// point it returns an error and the server exits.
	if <-stategen {
		return new(StdioConn), nil
	}
	return nil, errors.New("Done")
}

func (sl *StdioListener) Close() error {
	return nil
}

func (sl *StdioListener) Addr() net.Addr {
	return &net.IPAddr{net.IPv4(0, 0, 0, 0)}
}

// Conn impl

func (sl *StdioConn) Read(b []byte) (int, error) {
	return os.Stdin.Read(b)
}

func (sl *StdioConn) Write(b []byte) (int, error) {
	return os.Stdout.Write(b)
}

func (sl *StdioConn) LocalAddr() net.Addr {
	return &net.IPAddr{net.IPv4(0, 0, 0, 0)}
}

func (sl *StdioConn) RemoteAddr() net.Addr {
	return sl.LocalAddr()
}

func (sl *StdioConn) SetDeadline(t time.Time) error {
	return nil
}

func (sl *StdioConn) SetReadDeadline(t time.Time) error {
	return nil
}

func (sl *StdioConn) SetWriteDeadline(t time.Time) error {
	return nil
}

func (sl *StdioConn) Close() error {
	stategen <- false
	return nil
}

func main() {
	s := http.Server{}
	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprintf(w, "Hello, %q\n", r.URL.Path)
	})

	// Must send this async or it deadlocks
	go func() { stategen <- true }()

	var sl StdioListener
	s.Serve(&sl)
}