sdk/go/httpserver/logger.go

   1 // Copyright (C) The Arvados Authors. All rights reserved.
   2 //
   3 // SPDX-License-Identifier: Apache-2.0
   4
   5 package httpserver
   6
   7 import (
   8         "context"
   9         "net/http"
  10         "time"
  11
  12         "git.arvados.org/arvados.git/sdk/go/ctxlog"
  13         "git.arvados.org/arvados.git/sdk/go/stats"
  14         "github.com/sirupsen/logrus"
  15 )
  16
  17 type contextKey struct {
  18         name string
  19 }
  20
  21 var (
  22         requestTimeContextKey = contextKey{"requestTime"}
  23 )
  24
  25 // HandlerWithContext returns an http.Handler that changes the request
  26 // context to ctx (replacing http.Server's default
  27 // context.Background()), then calls next.
  28 func HandlerWithContext(ctx context.Context, next http.Handler) http.Handler {
  29         return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
  30                 next.ServeHTTP(w, r.WithContext(ctx))
  31         })
  32 }
  33
  34 // LogRequests wraps an http.Handler, logging each request and
  35 // response.
  36 func LogRequests(h http.Handler) http.Handler {
  37         return http.HandlerFunc(func(wrapped http.ResponseWriter, req *http.Request) {
  38                 w := &responseTimer{ResponseWriter: WrapResponseWriter(wrapped)}
  39                 lgr := ctxlog.FromContext(req.Context()).WithFields(logrus.Fields{
  40                         "RequestID":       req.Header.Get("X-Request-Id"),
  41                         "remoteAddr":      req.RemoteAddr,
  42                         "reqForwardedFor": req.Header.Get("X-Forwarded-For"),
  43                         "reqMethod":       req.Method,
  44                         "reqHost":         req.Host,
  45                         "reqPath":         req.URL.Path[1:],
  46                         "reqQuery":        req.URL.RawQuery,
  47                         "reqBytes":        req.ContentLength,
  48                 })
  49                 ctx := req.Context()
  50                 ctx = context.WithValue(ctx, &requestTimeContextKey, time.Now())
  51                 ctx = ctxlog.Context(ctx, lgr)
  52                 req = req.WithContext(ctx)
  53
  54                 logRequest(w, req, lgr)
  55                 defer logResponse(w, req, lgr)
  56                 h.ServeHTTP(rewrapResponseWriter(w, wrapped), req)
  57         })
  58 }
  59
  60 // Rewrap w to restore additional interfaces provided by wrapped.
  61 func rewrapResponseWriter(w http.ResponseWriter, wrapped http.ResponseWriter) http.ResponseWriter {
  62         if hijacker, ok := wrapped.(http.Hijacker); ok {
  63                 return struct {
  64                         http.ResponseWriter
  65                         http.Hijacker
  66                 }{w, hijacker}
  67         }
  68         return w
  69 }
  70
  71 func Logger(req *http.Request) logrus.FieldLogger {
  72         return ctxlog.FromContext(req.Context())
  73 }
  74
  75 func logRequest(w *responseTimer, req *http.Request, lgr *logrus.Entry) {
  76         lgr.Info("request")
  77 }
  78
  79 func logResponse(w *responseTimer, req *http.Request, lgr *logrus.Entry) {
  80         if tStart, ok := req.Context().Value(&requestTimeContextKey).(time.Time); ok {
  81                 tDone := time.Now()
  82                 writeTime := w.writeTime
  83                 if !w.wrote {
  84                         // Empty response body. Header was sent when
  85                         // handler exited.
  86                         writeTime = tDone
  87                 }
  88                 lgr = lgr.WithFields(logrus.Fields{
  89                         "timeTotal":     stats.Duration(tDone.Sub(tStart)),
  90                         "timeToStatus":  stats.Duration(writeTime.Sub(tStart)),
  91                         "timeWriteBody": stats.Duration(tDone.Sub(writeTime)),
  92                 })
  93         }
  94         respCode := w.WroteStatus()
  95         if respCode == 0 {
  96                 respCode = http.StatusOK
  97         }
  98         fields := logrus.Fields{
  99                 "respStatusCode": respCode,
 100                 "respStatus":     http.StatusText(respCode),
 101                 "respBytes":      w.WroteBodyBytes(),
 102         }
 103         if respCode >= 400 {
 104                 fields["respBody"] = string(w.Sniffed())
 105         }
 106         lgr.WithFields(fields).Info("response")
 107 }
 108
 109 type responseTimer struct {
 110         ResponseWriter
 111         wrote     bool
 112         writeTime time.Time
 113 }
 114
 115 func (rt *responseTimer) CloseNotify() <-chan bool {
 116         if cn, ok := rt.ResponseWriter.(http.CloseNotifier); ok {
 117                 return cn.CloseNotify()
 118         }
 119         return nil
 120 }
 121
 122 func (rt *responseTimer) WriteHeader(code int) {
 123         if !rt.wrote {
 124                 rt.wrote = true
 125                 rt.writeTime = time.Now()
 126         }
 127         rt.ResponseWriter.WriteHeader(code)
 128 }
 129
 130 func (rt *responseTimer) Write(p []byte) (int, error) {
 131         if !rt.wrote {
 132                 rt.wrote = true
 133                 rt.writeTime = time.Now()
 134         }
 135         return rt.ResponseWriter.Write(p)
 136 }