FM / persistent-https

/usr/share/doc/git/contrib/persistent-https/

/usr/share/doc/git/contrib/persistent-https

Name	Size	Mode	Actions
client.go	4937	0644	edit dl rm
LICENSE	11358	0644	edit dl rm
main.go	2424	0644	edit dl rm
Makefile	1500	0644	edit dl rm
proxy.go	4786	0644	edit dl rm
README	1989	0644	edit dl rm
socket.go	2917	0644	edit dl rm

Edit: /usr/share/doc/git/contrib/persistent-https/proxy.go (4786B)

// Copyright 2012 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package main

import (
	"fmt"
	"log"
	"net"
	"net/http"
	"net/http/httputil"
	"os"
	"os/exec"
	"os/signal"
	"sync"
	"syscall"
	"time"
)

type Proxy struct {
	BuildLabel         string
	MaxIdleDuration    time.Duration
	PollUpdateInterval time.Duration

ul        net.Listener
	httpAddr  string
	httpsAddr string
}

func (p *Proxy) Run() error {
	hl, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		return fmt.Errorf("http listen failed: %v", err)
	}
	defer hl.Close()

hsl, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		return fmt.Errorf("https listen failed: %v", err)
	}
	defer hsl.Close()

p.ul, err = DefaultSocket.Listen()
	if err != nil {
		c, derr := DefaultSocket.Dial()
		if derr == nil {
			c.Close()
			fmt.Println("OK\nA proxy is already running... exiting")
			return nil
		} else if e, ok := derr.(*net.OpError); ok && e.Err == syscall.ECONNREFUSED {
			// Nothing is listening on the socket, unlink it and try again.
			syscall.Unlink(DefaultSocket.Path())
			p.ul, err = DefaultSocket.Listen()
		}
		if err != nil {
			return fmt.Errorf("unix listen failed on %v: %v", DefaultSocket.Path(), err)
		}
	}
	defer p.ul.Close()
	go p.closeOnSignal()
	go p.closeOnUpdate()

p.httpAddr = hl.Addr().String()
	p.httpsAddr = hsl.Addr().String()
	fmt.Printf("OK\nListening on unix socket=%v http=%v https=%v\n",
		p.ul.Addr(), p.httpAddr, p.httpsAddr)

result := make(chan error, 2)
	go p.serveUnix(result)
	go func() {
		result <- http.Serve(hl, &httputil.ReverseProxy{
			FlushInterval: 500 * time.Millisecond,
			Director:      func(r *http.Request) {},
		})
	}()
	go func() {
		result <- http.Serve(hsl, &httputil.ReverseProxy{
			FlushInterval: 500 * time.Millisecond,
			Director: func(r *http.Request) {
				r.URL.Scheme = "https"
			},
		})
	}()
	return <-result
}

type socketContext struct {
	sync.WaitGroup
	mutex sync.Mutex
	last  time.Time
}

func (sc *socketContext) Done() {
	sc.mutex.Lock()
	defer sc.mutex.Unlock()
	sc.last = time.Now()
	sc.WaitGroup.Done()
}

func (p *Proxy) serveUnix(result chan<- error) {
	sockCtx := &socketContext{}
	go p.closeOnIdle(sockCtx)

var err error
	for {
		var uconn net.Conn
		uconn, err = p.ul.Accept()
		if err != nil {
			err = fmt.Errorf("accept failed: %v", err)
			break
		}
		sockCtx.Add(1)
		go p.handleUnixConn(sockCtx, uconn)
	}
	sockCtx.Wait()
	result <- err
}

func (p *Proxy) handleUnixConn(sockCtx *socketContext, uconn net.Conn) {
	defer sockCtx.Done()
	defer uconn.Close()
	data := []byte(fmt.Sprintf("%v\n%v", p.httpsAddr, p.httpAddr))
	uconn.SetDeadline(time.Now().Add(5 * time.Second))
	for i := 0; i < 2; i++ {
		if n, err := uconn.Write(data); err != nil {
			log.Printf("error sending http addresses: %+v\n", err)
			return
		} else if n != len(data) {
			log.Printf("sent %d data bytes, wanted %d\n", n, len(data))
			return
		}
		if _, err := uconn.Read([]byte{0, 0, 0, 0}); err != nil {
			log.Printf("error waiting for Ack: %+v\n", err)
			return
		}
	}
	// Wait without a deadline for the client to finish via EOF
	uconn.SetDeadline(time.Time{})
	uconn.Read([]byte{0, 0, 0, 0})
}

func (p *Proxy) closeOnIdle(sockCtx *socketContext) {
	for d := p.MaxIdleDuration; d > 0; {
		time.Sleep(d)
		sockCtx.Wait()
		sockCtx.mutex.Lock()
		if d = sockCtx.last.Add(p.MaxIdleDuration).Sub(time.Now()); d <= 0 {
			log.Println("graceful shutdown from idle timeout")
			p.ul.Close()
		}
		sockCtx.mutex.Unlock()
	}
}

func (p *Proxy) closeOnUpdate() {
	for {
		time.Sleep(p.PollUpdateInterval)
		if out, err := exec.Command(os.Args[0], "--print_label").Output(); err != nil {
			log.Printf("error polling for updated binary: %v\n", err)
		} else if s := string(out[:len(out)-1]); p.BuildLabel != s {
			log.Printf("graceful shutdown from updated binary: %q --> %q\n", p.BuildLabel, s)
			p.ul.Close()
			break
		}
	}
}

func (p *Proxy) closeOnSignal() {
	ch := make(chan os.Signal, 10)
	signal.Notify(ch, os.Interrupt, os.Kill, os.Signal(syscall.SIGTERM), os.Signal(syscall.SIGHUP))
	sig := <-ch
	p.ul.Close()
	switch sig {
	case os.Signal(syscall.SIGHUP):
		log.Printf("graceful shutdown from signal: %v\n", sig)
	default:
		log.Fatalf("exiting from signal: %v\n", sig)
	}
}

cmd: