imgsrv/vendor/github.com/vbatts/go-httplog/httplog.go

package httplog

import (
	"fmt"
	"net"
	"net/http"
	"strings"
	"time"

	"github.com/Sirupsen/logrus"
)

var (
	/* This default icon is empty with a long lived cache */
	DefaultFavIcon FavIcon = defaultFavIcon{}
)

type defaultFavIcon struct {
}

func (dfi defaultFavIcon) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	LogRequest(r, 200)
	w.Header().Set("Cache-Control", "max-age=315360000")
}

/* simple interface for a favicon */
type FavIcon interface {
	ServeHTTP(w http.ResponseWriter, r *http.Request)
}

// for debugging request headers
func LogHeaders(r *http.Request) {
	fmt.Printf("HEADERS:\n")
	for k, v := range r.Header {
		fmt.Printf("\t%s\n", k)
		for i, _ := range v {
			fmt.Printf("\t\t%s\n", v[i])
		}
	}
}

/* kindof a common log type output */
func LogRequest(r *http.Request, statusCode int) {
	var addr string
	var user_agent string

	user_agent = ""
	addr = RealIP(r)

	for k, v := range r.Header {
		if k == "User-Agent" {
			user_agent = strings.Join(v, " ")
		}
		if k == "X-Forwarded-For" {
			addr = strings.Join(v, " ")
		}
	}

	fmt.Printf("%s - - [%s] \"%s %s\" \"%s\" %d %d\n",
		addr,
		time.Now().Format(time.RFC1123Z),
		r.Method,
		r.URL.String(),
		user_agent,
		statusCode,
		r.ContentLength)
}

func RealIP(r *http.Request) string {
	rip := RealIPs(r)
	if len(rip) == 0 {
		return ""
	}
	return rip[len(rip)-1]
}

func RealIPs(r *http.Request) (ips []string) {
	logrus.Infof("httplog: RemoteAddr: %q", r.RemoteAddr)
	ip, _, err := net.SplitHostPort(r.RemoteAddr)
	if err != nil {
		logrus.Errorf("httplog: %q", err)
		return nil
	}

	if ip != "" {
		ips = append(ips, ip)
	}

	val := r.Header.Get("X-Forwarded-For")
	logrus.Infof("httplog: X-Forwarded-For: %q", val)
	if val != "" {
		for _, ip := range strings.Split(val, ", ") {
			ips = append(ips, ip)
		}
	}
	return ips
}