microservices-demo/src/frontend/middleware.go

106 lines
2.6 KiB
Go

// Copyright 2018 Google LLC
//
// 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 (
"context"
"net/http"
"time"
"github.com/google/uuid"
"github.com/sirupsen/logrus"
)
type ctxKeyLog struct{}
type ctxKeyRequestID struct{}
type logHandler struct {
log *logrus.Logger
next http.Handler
}
type responseRecorder struct {
b int
status int
w http.ResponseWriter
}
func (r *responseRecorder) Header() http.Header { return r.w.Header() }
func (r *responseRecorder) Write(p []byte) (int, error) {
if r.status == 0 {
r.status = http.StatusOK
}
n, err := r.w.Write(p)
r.b += n
return n, err
}
func (r *responseRecorder) WriteHeader(statusCode int) {
r.status = statusCode
r.w.WriteHeader(statusCode)
}
func (lh *logHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
ctx := r.Context()
requestID, _ := uuid.NewRandom()
ctx = context.WithValue(ctx, ctxKeyRequestID{}, requestID.String())
start := time.Now()
rr := &responseRecorder{w: w}
log := lh.log.WithFields(logrus.Fields{
"http.req.path": r.URL.Path,
"http.req.method": r.Method,
"http.req.id": requestID.String(),
})
if v, ok := r.Context().Value(ctxKeySessionID{}).(string); ok {
log = log.WithField("session", v)
}
log.Debug("request started")
defer func() {
log.WithFields(logrus.Fields{
"http.resp.took_ms": int64(time.Since(start) / time.Millisecond),
"http.resp.status": rr.status,
"http.resp.bytes": rr.b}).Debugf("request complete")
}()
ctx = context.WithValue(ctx, ctxKeyLog{}, log)
r = r.WithContext(ctx)
lh.next.ServeHTTP(rr, r)
}
func ensureSessionID(next http.Handler) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
var sessionID string
c, err := r.Cookie(cookieSessionID)
if err == http.ErrNoCookie {
u, _ := uuid.NewRandom()
sessionID = u.String()
http.SetCookie(w, &http.Cookie{
Name: cookieSessionID,
Value: sessionID,
MaxAge: cookieMaxAge,
})
} else if err != nil {
return
} else {
sessionID = c.Value
}
ctx := context.WithValue(r.Context(), ctxKeySessionID{}, sessionID)
r = r.WithContext(ctx)
next.ServeHTTP(w, r)
}
}