ecadlabs/signatory

package middlewares

// Logging middleware inspired by github.com/urfave/negroni

import (
    "net/http"
    "time"

    log "github.com/sirupsen/logrus"
)

func (rw *responseWriter) Status() int {
    return rw.status
}

func (rw *responseWriter) WriteHeader(s int) {
    rw.status = s
    rw.ResponseWriter.WriteHeader(s)
}

func (rw *responseWriter) Write(data []byte) (int, error) {
    if rw.status == 0 {
        rw.status = http.StatusOK
    }

    return rw.ResponseWriter.Write(data)
}

var _ http.ResponseWriter = &responseWriter{}
var _ http.ResponseWriter = &responseWriterHijacker{}
var _ http.Hijacker = &responseWriterHijacker{}

// ResponseStatusWriter wraps http.ResponseWriter to save HTTP status code
type ResponseStatusWriter interface {
    http.ResponseWriter
    Status() int
}

type responseWriter struct {
    http.ResponseWriter
    status int
}

type responseWriterHijacker struct {
    *responseWriter
    http.Hijacker
}

func newResponseStatusWriter(w http.ResponseWriter) ResponseStatusWriter {
    ret := &responseWriter{
        ResponseWriter: w,
    }

    if h, ok := w.(http.Hijacker); ok {
        return &responseWriterHijacker{
            responseWriter: ret,
            Hijacker:       h,
        }
    }

    return ret
}

// Logging is a logrus-enabled logging middleware
type Logging struct {
    Logger *log.Logger
}

func (l *Logging) log() *log.Logger {
    if l.Logger != nil {
        return l.Logger
    }
    return log.StandardLogger()
}

// Handler wraps provided http.Handler with middleware
func (l *Logging) Handler(h http.Handler) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        timestamp := time.Now()

        rw := newResponseStatusWriter(w)
        h.ServeHTTP(rw, r)

        fields := log.Fields{
            "start_time": timestamp.Format(time.RFC3339),
            "duration":   time.Since(timestamp),
            "status":     rw.Status(),
            "hostname":   r.Host,
            "method":     r.Method,
            "path":       r.URL.Path,
        }

        l.log().WithFields(fields).Println(r.Method + " " + r.URL.Path)
    })
}