Add support for exchanges to RabbitMQ input (#3619)

plugins/inputs/rabbitmq/README.md

@@ -40,6 +40,10 @@ For additional details reference the [RabbitMQ Management HTTP Stats](https://cd
   ## A list of queues to gather as the rabbitmq_queue measurement. If not
   ## specified, metrics for all queues are gathered.
   # queues = ["telegraf"]
+
+  ## A list of exchanges to gather as the rabbitmq_exchange measurement. If not
+  ## specified, metrics for all exchanges are gathered.
+  # exchanges = ["telegraf"]
 ```
 
 ### Measurements & Fields:
@@ -95,6 +99,10 @@ For additional details reference the [RabbitMQ Management HTTP Stats](https://cd
   - messages_redeliver_rate (float, messages per second)
   - messages_unack (integer, count)
 
+- rabbitmq_exchange
+  - messages_publish_in (int, count)
+  - messages_publish_out (int, count)
+
 ### Tags:
 
 - All measurements have the following tags:
@@ -114,6 +122,15 @@ For additional details reference the [RabbitMQ Management HTTP Stats](https://cd
   - durable
   - auto_delete
 
+- rabbitmq_exchange
+  - url
+  - exchange
+  - type
+  - vhost
+  - internal
+  - durable
+  - auto_delete
+
 ### Sample Queries:
 
 Message rates for the entire node can be calculated from total message counts. For instance, to get the rate of messages published per minute, use this query:
@@ -129,4 +146,5 @@ FROM rabbitmq_overview WHERE time > now() - 10m GROUP BY time(1m)
 rabbitmq_queue,url=http://amqp.example.org:15672,queue=telegraf,vhost=influxdb,node=rabbit@amqp.example.org,durable=true,auto_delete=false,host=amqp.example.org messages_deliver_get=0i,messages_publish=329i,messages_publish_rate=0.2,messages_redeliver_rate=0,message_bytes_ready=0i,message_bytes_unacked=0i,messages_deliver=329i,messages_unack=0i,consumers=1i,idle_since="",messages=0i,messages_deliver_rate=0.2,messages_deliver_get_rate=0.2,messages_redeliver=0i,memory=43032i,message_bytes_ram=0i,messages_ack=329i,messages_ready=0i,messages_ack_rate=0.2,consumer_utilisation=1,message_bytes=0i,message_bytes_persist=0i 1493684035000000000
 rabbitmq_overview,url=http://amqp.example.org:15672,host=amqp.example.org channels=2i,consumers=1i,exchanges=17i,messages_acked=329i,messages=0i,messages_ready=0i,messages_unacked=0i,connections=2i,queues=1i,messages_delivered=329i,messages_published=329i 1493684035000000000
 rabbitmq_node,url=http://amqp.example.org:15672,node=rabbit@amqp.example.org,host=amqp.example.org fd_total=1024i,fd_used=32i,mem_limit=8363329126i,sockets_total=829i,disk_free=8175935488i,disk_free_limit=50000000i,mem_used=58771080i,proc_total=1048576i,proc_used=267i,run_queue=0i,sockets_used=2i 149368403500000000
+rabbitmq_exchange,url=http://amqp.example.org:15672,exchange=telegraf,type=fanout,vhost=influxdb,internal=false,durable=true,auto_delete=false,host=amqp.example.org messages_publish_in=2i,messages_publish_out=1i 149368403500000000
 ```

plugins/inputs/rabbitmq/rabbitmq.go

@@ -50,6 +50,7 @@ type RabbitMQ struct {
 
 	Nodes     []string
 	Queues    []string
+	Exchanges []string
 
 	Client *http.Client
 }
@@ -78,6 +79,8 @@ type MessageStats struct {
 	PublishDetails    Details `json:"publish_details"`
 	Redeliver         int64
 	RedeliverDetails  Details `json:"redeliver_details"`
+	PublishIn         int64   `json:"publish_in"`
+	PublishOut        int64   `json:"publish_out"`
 }
 
 // ObjectTotals ...
@@ -133,10 +136,20 @@ type Node struct {
 	SocketsUsed   int64 `json:"sockets_used"`
 }
 
+type Exchange struct {
+	Name         string
+	MessageStats `json:"message_stats"`
+	Type         string
+	Internal     bool
+	Vhost        string
+	Durable      bool
+	AutoDelete   bool `json:"auto_delete"`
+}
+
 // gatherFunc ...
 type gatherFunc func(r *RabbitMQ, acc telegraf.Accumulator)
 
-var gatherFunctions = []gatherFunc{gatherOverview, gatherNodes, gatherQueues}
+var gatherFunctions = []gatherFunc{gatherOverview, gatherNodes, gatherQueues, gatherExchanges}
 
 var sampleConfig = `
   ## Management Plugin url. (default: http://localhost:15672)
@@ -171,6 +184,10 @@ var sampleConfig = `
   ## A list of queues to gather as the rabbitmq_queue measurement. If not
   ## specified, metrics for all queues are gathered.
   # queues = ["telegraf"]
+
+  ## A list of exchanges to gather as the rabbitmq_exchange measurement. If not
+  ## specified, metrics for all exchanges are gathered. 
+  # exchanges = ["telegraf"]
 `
 
 // SampleConfig ...
@@ -374,6 +391,40 @@ func gatherQueues(r *RabbitMQ, acc telegraf.Accumulator) {
 	}
 }
 
+func gatherExchanges(r *RabbitMQ, acc telegraf.Accumulator) {
+	// Gather information about exchanges
+	exchanges := make([]Exchange, 0)
+	err := r.requestJSON("/api/exchanges", &exchanges)
+	if err != nil {
+		acc.AddError(err)
+		return
+	}
+
+	for _, exchange := range exchanges {
+		if !r.shouldGatherExchange(exchange) {
+			continue
+		}
+		tags := map[string]string{
+			"url":         r.URL,
+			"exchange":    exchange.Name,
+			"type":        exchange.Type,
+			"vhost":       exchange.Vhost,
+			"internal":    strconv.FormatBool(exchange.Internal),
+			"durable":     strconv.FormatBool(exchange.Durable),
+			"auto_delete": strconv.FormatBool(exchange.AutoDelete),
+		}
+
+		acc.AddFields(
+			"rabbitmq_exchange",
+			map[string]interface{}{
+				"messages_publish_in":  exchange.MessageStats.PublishIn,
+				"messages_publish_out": exchange.MessageStats.PublishOut,
+			},
+			tags,
+		)
+	}
+}
+
 func (r *RabbitMQ) shouldGatherNode(node Node) bool {
 	if len(r.Nodes) == 0 {
 		return true
@@ -402,6 +453,20 @@ func (r *RabbitMQ) shouldGatherQueue(queue Queue) bool {
 	return false
 }
 
+func (r *RabbitMQ) shouldGatherExchange(exchange Exchange) bool {
+	if len(r.Exchanges) == 0 {
+		return true
+	}
+
+	for _, name := range r.Exchanges {
+		if name == exchange.Name {
+			return true
+		}
+	}
+
+	return false
+}
+
 func init() {
 	inputs.Add("rabbitmq", func() telegraf.Input {
 		return &RabbitMQ{

plugins/inputs/rabbitmq/rabbitmq_test.go

@@ -374,6 +374,102 @@ const sampleQueuesResponse = `
 ]
 `
 
+const sampleExchangesResponse = `
+[
+  {
+    "arguments": { },
+    "internal": false,
+    "auto_delete": false,
+    "durable": true,
+    "type": "direct",
+    "vhost": "\/",
+    "name": ""
+  },
+  {
+    "message_stats": {
+      "publish_in_details": {
+        "rate": 0
+      },
+      "publish_in": 2,
+      "publish_out_details": {
+        "rate": 0
+      },
+      "publish_out": 1
+    },
+    "arguments": { },
+    "internal": false,
+    "auto_delete": false,
+    "durable": true,
+    "type": "fanout",
+    "vhost": "\/",
+    "name": "telegraf"
+  },
+  {
+    "arguments": { },
+    "internal": false,
+    "auto_delete": false,
+    "durable": true,
+    "type": "direct",
+    "vhost": "\/",
+    "name": "amq.direct"
+  },
+  {
+    "arguments": { },
+    "internal": false,
+    "auto_delete": false,
+    "durable": true,
+    "type": "fanout",
+    "vhost": "\/",
+    "name": "amq.fanout"
+  },
+  {
+    "arguments": { },
+    "internal": false,
+    "auto_delete": false,
+    "durable": true,
+    "type": "headers",
+    "vhost": "\/",
+    "name": "amq.headers"
+  },
+  {
+    "arguments": { },
+    "internal": false,
+    "auto_delete": false,
+    "durable": true,
+    "type": "headers",
+    "vhost": "\/",
+    "name": "amq.match"
+  },
+  {
+    "arguments": { },
+    "internal": true,
+    "auto_delete": false,
+    "durable": true,
+    "type": "topic",
+    "vhost": "\/",
+    "name": "amq.rabbitmq.log"
+  },
+  {
+    "arguments": { },
+    "internal": true,
+    "auto_delete": false,
+    "durable": true,
+    "type": "topic",
+    "vhost": "\/",
+    "name": "amq.rabbitmq.trace"
+  },
+  {
+    "arguments": { },
+    "internal": false,
+    "auto_delete": false,
+    "durable": true,
+    "type": "topic",
+    "vhost": "\/",
+    "name": "amq.topic"
+  }
+]
+`
+
 func TestRabbitMQGeneratesMetrics(t *testing.T) {
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		var rsp string
@@ -385,6 +481,8 @@ func TestRabbitMQGeneratesMetrics(t *testing.T) {
 			rsp = sampleNodesResponse
 		case "/api/queues":
 			rsp = sampleQueuesResponse
+		case "/api/exchanges":
+			rsp = sampleExchangesResponse
 		default:
 			panic("Cannot handle request")
 		}
@@ -441,4 +539,13 @@ func TestRabbitMQGeneratesMetrics(t *testing.T) {
 	}
 
 	assert.True(t, acc.HasMeasurement("rabbitmq_queue"))
+
+	exchangeIntMetrics := []string{
+		"messages_publish_in",
+		"messages_publish_out",
+	}
+
+	for _, metric := range exchangeIntMetrics {
+		assert.True(t, acc.HasInt64Field("rabbitmq_exchange", metric))
+	}
 }