Add queue_durability parameter to amqp_consumer input (#4628)

plugins/inputs/amqp_consumer/README.md

@@ -46,6 +46,10 @@ The following defaults are known to work with RabbitMQ:
 
   ## AMQP queue name
   queue = "telegraf"
+  
+  ## AMQP queue durability can be "transient" or "durable".
+  queue_durability = "durable"
+  
   ## Binding Key
   binding_key = "#"
 

plugins/inputs/amqp_consumer/amqp_consumer.go

@@ -30,7 +30,9 @@ type AMQPConsumer struct {
 	ExchangeArguments  map[string]string `toml:"exchange_arguments"`
 
 	// Queue Name
-	Queue string
+	Queue           string `toml:"queue"`
+	QueueDurability string `toml:"queue_durability"`
+
 	// Binding Key
 	BindingKey string `toml:"binding_key"`
 
@@ -64,6 +66,8 @@ const (
 	DefaultExchangeType       = "topic"
 	DefaultExchangeDurability = "durable"
 
+	DefaultQueueDurability = "durable"
+
 	DefaultPrefetchCount = 50
 )
 
@@ -98,10 +102,13 @@ func (a *AMQPConsumer) SampleConfig() string {
   # exchange_arguments = { }
   # exchange_arguments = {"hash_propery" = "timestamp"}
 
-  ## AMQP queue name
+  ## AMQP queue name.
   queue = "telegraf"
 
-  ## Binding Key
+  ## AMQP queue durability can be "transient" or "durable".
+  queue_durability = "durable"
+
+  ## Binding Key.
   binding_key = "#"
 
   ## Maximum number of messages server should give to the worker.
@@ -260,13 +267,21 @@ func (a *AMQPConsumer) connect(amqpConf *amqp.Config) (<-chan amqp.Delivery, err
 		return nil, err
 	}
 
+	var queueDurable = true
+	switch a.QueueDurability {
+	case "transient":
+		queueDurable = false
+	default:
+		queueDurable = true
+	}
+
 	q, err := ch.QueueDeclare(
-		a.Queue, // queue
-		true,    // durable
-		false,   // delete when unused
-		false,   // exclusive
-		false,   // no-wait
-		nil,     // arguments
+		a.Queue,      // queue
+		queueDurable, // durable
+		false,        // delete when unused
+		false,        // exclusive
+		false,        // no-wait
+		nil,          // arguments
 	)
 	if err != nil {
 		return nil, fmt.Errorf("Failed to declare a queue: %s", err)
@@ -380,6 +395,7 @@ func init() {
 			AuthMethod:         DefaultAuthMethod,
 			ExchangeType:       DefaultExchangeType,
 			ExchangeDurability: DefaultExchangeDurability,
+			QueueDurability:    DefaultQueueDurability,
 			PrefetchCount:      DefaultPrefetchCount,
 		}
 	})