Use Header.Set() to override the existing header value (#1032)

Header.Add() appends string if there are same header key exists. Use Header.Set() to prevent this.

mqtrigger/messageQueue/asq.go

@@ -313,14 +313,14 @@ func invokeTriggeredFunction(conn AzureStorageConnection, sub *AzureQueueSubscri
 			continue
 		}
 
-		request.Header.Add("X-Fission-MQTrigger-Topic", sub.queueName)
+		request.Header.Set("X-Fission-MQTrigger-Topic", sub.queueName)
 		if len(sub.outputQueueName) > 0 {
-			request.Header.Add("X-Fission-MQTrigger-RespTopic", sub.outputQueueName)
+			request.Header.Set("X-Fission-MQTrigger-RespTopic", sub.outputQueueName)
 		}
 		if i > 0 {
-			request.Header.Add("X-Fission-MQTrigger-RetryCount", strconv.Itoa(i))
+			request.Header.Set("X-Fission-MQTrigger-RetryCount", strconv.Itoa(i))
 		}
-		request.Header.Add("Content-Type", sub.contentType)
+		request.Header.Set("Content-Type", sub.contentType)
 
 		response, err := conn.httpClient.Do(request)
 		if err != nil {

mqtrigger/messageQueue/kafka.go

@@ -133,7 +133,7 @@ func kafkaMsgHandler(kafka *Kafka, producer sarama.SyncProducer, trigger *crd.Me
 	}
 
 	for k, v := range headers {
-		req.Header.Add(k, v)
+		req.Header.Set(k, v)
 	}
 	// Make the request
 	var resp *http.Response

mqtrigger/messageQueue/nats.go

@@ -122,7 +122,7 @@ func msgHandler(nats *Nats, trigger *crd.MessageQueueTrigger) func(*ns.Msg) {
 		}
 
 		for k, v := range headers {
-			req.Header.Add(k, v)
+			req.Header.Set(k, v)
 		}
 
 		var resp *http.Response