Webhook 概述

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// Full Go sample code: https://github.com/Frameio/webhooks-example-app/blob/master/main.go
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func handler(w http.ResponseWriter, r *http.Request) {
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	out, err := httputil.DumpRequest(r, true)
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	if err != nil {
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		w.WriteHeader(http.StatusInternalServerError)
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		return
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	}
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	log.Println(string(out))
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	// Verify the message has been delivered in the last 5 minutes.
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	timestampStr := r.Header.Get("X-Frameio-Request-Timestamp")
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	timestamp, err := strconv.ParseInt(timestampStr, 10, 64)
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	if err != nil {
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		w.WriteHeader(http.StatusBadRequest)
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		return
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	}
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	if time.Since(time.Unix(timestamp, 0)) > 5*time.Minute {
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		w.WriteHeader(http.StatusBadRequest)
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		return
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	}
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	// Verify request signature.
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	expected := r.Header.Get("X-Frameio-Signature")
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	signature, _ := computeSignature(r, timestamp, secretKey)
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	if expected != signature {
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		w.WriteHeader(http.StatusUnauthorized)
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		return
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	}
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	var event *Event
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	decoder := json.NewDecoder(r.Body)
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	err = decoder.Decode(&event)
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	if err != nil {
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		w.WriteHeader(http.StatusInternalServerError)
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		return
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	}
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	// Handle webhook here.
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	log.Println(event.ID)
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	w.WriteHeader(http.StatusOK)
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}
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// The request includes headers to enable the recipient to validate
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// that the request is from Frame.io and that it's been delivered within
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// the expected time range. To learn more about how this works, take a
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// look at our docs https://docs.frame.io/docs/webhooks#section-security.
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func computeSignature(r *http.Request, timestamp int64, secret string) (string, error) {
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	body, err := ioutil.ReadAll(r.Body)
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	if err != nil {
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		return "", err
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	}
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	copy := body[:]
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	r.Body = ioutil.NopCloser(bytes.NewReader(copy))
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	msg := fmt.Sprintf("%s:%d:%s", version, timestamp, string(body))
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	key := []byte(secret)
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	h := hmac.New(sha256.New, key)
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	h.Write([]byte(msg))
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	result := fmt.Sprintf("%s=%s", version, hex.EncodeToString(h.Sum(nil)))
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	return result, nil
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}