feat: Prometheus Integration

README.md

@@ -402,6 +402,19 @@ try {
 
 ```
 
+## Metrics
+
+Metrics are following the [Prometheus](https://prometheus.io/docs/introduction/overview/) conventions.
+They are available via HTTP endpoint (http://127.0.0.1:9566/metrics), with default port `9566` and default path `/metrics`.
+
+The following metrics are tracked:
+
+| Metric                                           | Type      | Description |
+| ------------------------------------------------ | --------- | ----------- |
+| `rabbitmq_cli_consumer_process_total`            | Counter   | The total number of processes executed. Processes are aggregated by their exit code.  |
+| `rabbitmq_cli_consumer_process_duration_seconds` | Histogram | The time spent by the consumer to process the message. |
+| `rabbitmq_cli_consumer_message_duration_seconds` | Histogram | The time spent from publishing to finished processing the message. This requires the message to have the `timestamp` header set. |
+
 ## Contributing and license
 
 This library is licenced under [MIT](LICENSE). For information about how to

collector/collector.go

@@ -0,0 +1,37 @@
+package collector
+
+import "github.com/prometheus/client_golang/prometheus"
+
+const (
+	namespace = "rabbitmq_cli_consumer"
+)
+
+var (
+	// ProcessCounter is a Prometheus metric describing the total number of processes executed.
+	ProcessCounter = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: namespace,
+			Name:      "process_total",
+			Help:      "The total number of processes executed.",
+		},
+		[]string{"exit_code"},
+	)
+
+	// ProcessDuration is a Prometheus metric describing the time spent by the consumer to process the message.
+	ProcessDuration = prometheus.NewHistogram(
+		prometheus.HistogramOpts{
+			Namespace: namespace,
+			Name:      "process_duration_seconds",
+			Help:      "The time spent by the consumer to process the message.",
+		},
+	)
+
+	// MessageDuration is a Prometheus metric describing the time spent from publishing to finished processing the message.
+	MessageDuration = prometheus.NewHistogram(
+		prometheus.HistogramOpts{
+			Namespace: namespace,
+			Name:      "message_duration_seconds",
+			Help:      "The time spent from publishing to finished processing the message.",
+		},
+	)
+)

fixtures/TestEndToEnd/amqpUrlOutput.golden

@@ -5,6 +5,7 @@ Done.
 Setting QoS... 
 Succeeded setting QoS.
 Declaring queue "test"...
+Metrics disabled.
 Registering consumer... 
 Succeeded registering consumer.
 Waiting for messages...

fixtures/TestEndToEnd/compressedOutput.golden

@@ -5,6 +5,7 @@ Done.
 Setting QoS... 
 Succeeded setting QoS.
 Declaring queue "test"...
+Metrics disabled.
 Registering consumer... 
 Succeeded registering consumer.
 Waiting for messages...

fixtures/TestEndToEnd/defaultOutput.golden

@@ -5,6 +5,7 @@ Done.
 Setting QoS... 
 Succeeded setting QoS.
 Declaring queue "test"...
+Metrics disabled.
 Registering consumer... 
 Succeeded registering consumer.
 Waiting for messages...

fixtures/TestEndToEnd/envAmqpUrlNoConfigOutput.golden

@@ -5,6 +5,7 @@ Done.
 Setting QoS... 
 Succeeded setting QoS.
 Declaring queue "test"...
+Metrics disabled.
 Registering consumer... 
 Succeeded registering consumer.
 Waiting for messages...

fixtures/TestEndToEnd/envAmqpUrlOutput.golden

@@ -5,6 +5,7 @@ Done.
 Setting QoS... 
 Succeeded setting QoS.
 Declaring queue "test"...
+Metrics disabled.
 Registering consumer... 
 Succeeded registering consumer.
 Waiting for messages...

fixtures/TestEndToEnd/noAmqpUrlOutput.golden

@@ -5,6 +5,7 @@ Done.
 Setting QoS... 
 Succeeded setting QoS.
 Declaring queue "test"...
+Metrics disabled.
 Registering consumer... 
 Succeeded registering consumer.
 Waiting for messages...

fixtures/TestEndToEnd/noDeclareConfigOutput.golden

@@ -4,6 +4,7 @@ Opening channel...
 Done.
 Setting QoS... 
 Succeeded setting QoS.
+Metrics disabled.
 Registering consumer... 
 Succeeded registering consumer.
 Waiting for messages...

fixtures/TestEndToEnd/noDeclareOutput.golden

@@ -4,6 +4,7 @@ Opening channel...
 Done.
 Setting QoS... 
 Succeeded setting QoS.
+Metrics disabled.
 Registering consumer... 
 Succeeded registering consumer.
 Waiting for messages...

fixtures/TestEndToEnd/noLogsOutput.golden

@@ -5,6 +5,7 @@ Done.
 Setting QoS... 
 Succeeded setting QoS.
 Declaring queue "test"...
+Metrics disabled.
 Registering consumer... 
 Succeeded registering consumer.
 Waiting for messages...

fixtures/TestEndToEnd/outputOutput.golden

@@ -5,6 +5,7 @@ Done.
 Setting QoS... 
 Succeeded setting QoS.
 Declaring queue "test"...
+Metrics disabled.
 Registering consumer... 
 Succeeded registering consumer.
 Waiting for messages...

fixtures/TestEndToEnd/pipeOutput.golden

@@ -5,6 +5,7 @@ Done.
 Setting QoS... 
 Succeeded setting QoS.
 Declaring queue "test"...
+Metrics disabled.
 Registering consumer... 
 Succeeded registering consumer.
 Waiting for messages...

fixtures/TestEndToEnd/propertiesOutput.golden

@@ -5,6 +5,7 @@ Done.
 Setting QoS... 
 Succeeded setting QoS.
 Declaring queue "test"...
+Metrics disabled.
 Registering consumer... 
 Succeeded registering consumer.
 Waiting for messages...

fixtures/TestEndToEnd/queueNameOutput.golden

@@ -5,6 +5,7 @@ Done.
 Setting QoS... 
 Succeeded setting QoS.
 Declaring queue "altTest"...
+Metrics disabled.
 Registering consumer... 
 Succeeded registering consumer.
 Waiting for messages...

go.mod

@@ -1,10 +1,18 @@
 module github.com/corvus-ch/rabbitmq-cli-consumer
 
 require (
+	bou.ke/monkey v1.0.1
+	github.com/AlekSi/gocoverutil v0.2.0 // indirect
 	github.com/bketelsen/logr v0.0.0-20170116012416-f3d070bdd1c5
 	github.com/codegangsta/cli v1.20.1-0.20190203184040-693af58b4d51
 	github.com/corvus-ch/logr v0.0.0-20180917163152-45217966b77e
+	github.com/magiconair/properties v1.8.0
+	github.com/pkg/errors v0.8.1
+	github.com/prometheus/client_golang v0.9.2
+	github.com/sebdah/goldie v0.0.0-20190305024101-629351c67c53
 	github.com/streadway/amqp v0.0.0-20190224195609-f16568b23ee6
+	github.com/stretchr/testify v1.3.0
+	golang.org/x/tools v0.0.0-20190417223002-a5870b403859 // indirect
 	gopkg.in/gcfg.v1 v1.2.3
 	gopkg.in/warnings.v0 v0.1.2 // indirect
 )

go.sum

@@ -1,13 +1,46 @@
+bou.ke/monkey v1.0.1 h1:zEMLInw9xvNakzUUPjfS4Ds6jYPqCFx3m7bRmG5NH2U=
+bou.ke/monkey v1.0.1/go.mod h1:FgHuK96Rv2Nlf+0u1OOVDpCMdsWyOFmeeketDHE7LIg=
+github.com/AlekSi/gocoverutil v0.2.0 h1:lpfoGyib/qbTh7PajsBL6Upv3Fnn2o3A6Mn0naFR0E8=
+github.com/AlekSi/gocoverutil v0.2.0/go.mod h1:/SQ8potkEzPK7N0+EyZi8sPtf/nK3BnHjw7tVmlDdUs=
+github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
 github.com/bketelsen/logr v0.0.0-20170116012416-f3d070bdd1c5 h1:k5oblHm+AdEGmDZA1NwxXjKuinRB6WsEuloKQ3i5u5g=
 github.com/bketelsen/logr v0.0.0-20170116012416-f3d070bdd1c5/go.mod h1:to4EbfYTEzdQuHxVGz1ug+d7a3bqOjR1r02gJ1Xv4z8=
-github.com/codegangsta/cli v1.20.0 h1:iX1FXEgwzd5+XN6wk5cVHOGQj6Q3Dcp20lUeS4lHNTw=
-github.com/codegangsta/cli v1.20.0/go.mod h1:/qJNoX69yVSKu5o4jLyXAENLRyk1uhi7zkbQ3slBdOA=
 github.com/codegangsta/cli v1.20.1-0.20190203184040-693af58b4d51 h1:onG4micSoSE6AwEVQcPY2Z2H28kf/SFG6URw3Vs9Nz8=
 github.com/codegangsta/cli v1.20.1-0.20190203184040-693af58b4d51/go.mod h1:/qJNoX69yVSKu5o4jLyXAENLRyk1uhi7zkbQ3slBdOA=
 github.com/corvus-ch/logr v0.0.0-20180917163152-45217966b77e h1:wL16/ZX3hdvCz4Xuz2oWSA9g4tV1N4sNFD3MYEUdDQM=
 github.com/corvus-ch/logr v0.0.0-20180917163152-45217966b77e/go.mod h1:vDjLhcz5/6EgBgZdQ5BxE5YAzHHkkfX8XLMPOBhlg2c=
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/golang/protobuf v1.2.0 h1:P3YflyNX/ehuJFLhxviNdFxQPkGK5cDcApsge1SqnvM=
+github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/magiconair/properties v1.8.0 h1:LLgXmsheXeRoUOBOjtwPQCWIYqM/LU1ayDtDePerRcY=
+github.com/magiconair/properties v1.8.0/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
+github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
+github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
+github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/prometheus/client_golang v0.9.2/go.mod h1:OsXs2jCmiKlQ1lTBmv21f2mNfw4xf/QclQDMrYNZzcM=
+github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
+github.com/prometheus/common v0.0.0-20181126121408-4724e9255275/go.mod h1:daVV7qP5qjZbuso7PdcryaAu0sAZbrN9i7WWcTMWvro=
+github.com/prometheus/procfs v0.0.0-20181204211112-1dc9a6cbc91a/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
+github.com/sebdah/goldie v0.0.0-20190305024101-629351c67c53 h1:qR9Fm180+oJEk1tyg+3wysrby5LvT9Y2vD4uKdLZlYw=
+github.com/sebdah/goldie v0.0.0-20190305024101-629351c67c53/go.mod h1:lvjGftC8oe7XPtyrOidaMi0rp5B9+XY/ZRUynGnuaxQ=
 github.com/streadway/amqp v0.0.0-20190224195609-f16568b23ee6 h1:AyOf9zHp1p9orBslizUk3QhgmX6PaOoR/2FQar0C9Lw=
 github.com/streadway/amqp v0.0.0-20190224195609-f16568b23ee6/go.mod h1:1WNBiOZtZQLpVAyu0iTduoJL9hEsMloAK5XWrtW0xdY=
+github.com/stretchr/objx v0.1.0 h1:4G4v2dO3VZwixGIRoQ5Lfboy6nUhCyYzaqnIAPPhYs4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/net v0.0.0-20181201002055-351d144fa1fc/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/sync v0.0.0-20181108010431-42b317875d0f h1:Bl/8QSvNqXvPGPGXa2z5xUTmV7VDcZyvRZ+QQXkXTZQ=
+golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/tools v0.0.0-20190417223002-a5870b403859 h1:9IwAPkJAVzY3ES7jydtY2zc5YltyS6lQuXUJoqoWQYg=
+golang.org/x/tools v0.0.0-20190417223002-a5870b403859/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
 gopkg.in/gcfg.v1 v1.2.3 h1:m8OOJ4ccYHnx2f4gQwpno8nAX5OGOh7RLaaz0pj3Ogs=
 gopkg.in/gcfg.v1 v1.2.3/go.mod h1:yesOnuUOFQAhST5vPY4nbZsb/huCgGGXlipJsBn0b3o=
 gopkg.in/warnings.v0 v0.1.2 h1:wFXVbFY8DY5/xOe1ECiWdKCzZlxgshcYVNkBHstARME=

main.go

@@ -4,19 +4,24 @@ import (
 	"context"
 	"fmt"
 	stdlog "log"
+	"net/http"
 	"os"
 	"os/signal"
 	"strings"
 	"syscall"
+	"time"
 
 	"github.com/bketelsen/logr"
 	"github.com/codegangsta/cli"
 	"github.com/corvus-ch/rabbitmq-cli-consumer/acknowledger"
+	"github.com/corvus-ch/rabbitmq-cli-consumer/collector"
 	"github.com/corvus-ch/rabbitmq-cli-consumer/command"
 	"github.com/corvus-ch/rabbitmq-cli-consumer/config"
 	"github.com/corvus-ch/rabbitmq-cli-consumer/consumer"
 	"github.com/corvus-ch/rabbitmq-cli-consumer/log"
 	"github.com/corvus-ch/rabbitmq-cli-consumer/processor"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/streadway/amqp"
 )
 
@@ -27,7 +32,7 @@ var (
 )
 
 // flags is the list of global flags known to the application.
-var flags = []cli.Flag{
+var flags []cli.Flag = []cli.Flag{
 	cli.StringFlag{
 		Name:   "url, u",
 		Usage:  "Connect with RabbitMQ using `URL`",
@@ -73,6 +78,20 @@ var flags = []cli.Flag{
 		Name:  "no-declare",
 		Usage: "prevents the queue from being declared.",
 	},
+	cli.BoolFlag{
+		Name:  "metrics, m",
+		Usage: "enables metric to be exposed.",
+	},
+	cli.StringFlag{
+		Name:  "web.listen-address",
+		Usage: "Address on which to expose metrics and web interface.",
+		Value: ":9566",
+	},
+	cli.StringFlag{
+		Name:  "web.telemetry-path",
+		Usage: "Path under which to expose metrics.",
+		Value: "/metrics",
+	},
 }
 
 var ll logr.Logger
@@ -126,9 +145,46 @@ func Action(c *cli.Context) error {
 	}
 	defer client.Close()
 
+	if c.Bool("metrics") {
+		ll.Infof("Registering metrics server at %v", c.String("web.listen-address"))
+		setupAndServeMetrics(c.String("web.listen-address"), c.String("web.telemetry-path"))
+	} else {
+		ll.Infof("Metrics disabled.")
+	}
+
 	return consume(client, l)
 }
 
+func setupAndServeMetrics(addr string, path string) {
+	srv := &http.Server{
+		Addr: addr,
+		// Good practice to set timeouts to avoid Slowloris attacks.
+		WriteTimeout: time.Second * 15,
+		ReadTimeout:  time.Second * 15,
+		IdleTimeout:  time.Second * 60,
+	}
+
+	prometheus.MustRegister(collector.ProcessCounter)
+	prometheus.MustRegister(collector.ProcessDuration)
+	prometheus.MustRegister(collector.MessageDuration)
+
+	http.Handle(path, promhttp.Handler())
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte(`<html>
+			 <head><title>rabbitmq-cli-consumer</title></head>
+			 <body>
+			 <h1>rabbitmq-cli-consumer</h1>
+			 <p><a href='` + path + `'>Metrics</a></p>
+			 </body>
+			 </html>`))
+	})
+	go func() {
+		if err := srv.ListenAndServe(); err != nil {
+			panic(err)
+		}
+	}()
+}
+
 func consume(client *consumer.Consumer, l logr.Logger) error {
 	done := make(chan error)
 	sig := make(chan os.Signal, 1)

processor/processor.go

@@ -2,13 +2,17 @@ package processor
 
 import (
 	"os/exec"
+	"strconv"
 	"sync"
 	"syscall"
+	"time"
 
 	"github.com/bketelsen/logr"
 	"github.com/corvus-ch/rabbitmq-cli-consumer/acknowledger"
+	"github.com/corvus-ch/rabbitmq-cli-consumer/collector"
 	"github.com/corvus-ch/rabbitmq-cli-consumer/command"
 	"github.com/corvus-ch/rabbitmq-cli-consumer/delivery"
+	"github.com/prometheus/client_golang/prometheus"
 )
 
 // Processor describes the interface used by the consumer to process messages.
@@ -47,8 +51,15 @@ func (p *processor) Process(d delivery.Delivery) error {
 		return NewCreateCommandError(err)
 	}
 
+	start := time.Now()
 	exitCode := p.run()
 
+	collector.ProcessCounter.With(prometheus.Labels{"exit_code": strconv.Itoa(exitCode)}).Inc()
+	collector.ProcessDuration.Observe(time.Since(start).Seconds())
+	if !d.Properties().Timestamp.IsZero() {
+		collector.MessageDuration.Observe(time.Since(d.Properties().Timestamp).Seconds())
+	}
+
 	if err := p.ack.Ack(d, exitCode); err != nil {
 		return NewAcknowledgmentError(err)
 	}