Add message received timestamp to message JSON (#12)

* record timestamp when a message was received (preparation for #10)
* new JSON field XRabtapReceivedTimestamp recording timestamp when a message was received added
* change uuid library to githib.com/google/uuid
* fix linting erros
* simplified code

CHANGELOG.md

@@ -1,6 +1,12 @@
 
 # Changelog for rabtap
 
+## v1.17 (2019-06-13)
+
+* Timestamp when message was received by rabtap now stored in JSON format
+  in `XRabtapReceivedTimestamp` field.
+* Simplified code
+
 ## v1.16 (2019-04-03)
 
 * new option `--by-connection` for info command added, making `info` show

README.md

@@ -444,6 +444,7 @@ messages in the following format:
   "Redelivered": false,
   "Exchange": "amq.topic",
   "RoutingKey": "test-q-amq.topic-0",
+  "XRabtapReceivedTimestamp": "2019-06-13T19:33:51.920711583+02:00",
   "Body": "dGhpcyB0ZXN0IG1lc3NhZ2U .... IGFuZCBoZWFkZXJzIGFtcXAuVGFibGV7fQ=="
 }
 ...

cmd/rabtap/cmd_subscribe_integration_test.go

@@ -14,6 +14,7 @@ import (
 	"testing"
 	"time"
 
+	rabtap "github.com/jandelgado/rabtap/pkg"
 	"github.com/jandelgado/rabtap/pkg/testcommon"
 	"github.com/streadway/amqp"
 	"github.com/stretchr/testify/assert"
@@ -27,7 +28,7 @@ func TestCmdSubFailsEarlyWhenBrokerIsNotAvailable(t *testing.T) {
 			amqpURI:            "invalid uri",
 			queue:              "queue",
 			tlsConfig:          &tls.Config{},
-			messageReceiveFunc: func(*amqp.Delivery) error { return nil },
+			messageReceiveFunc: func(rabtap.TapMessage) error { return nil },
 			signalChannel:      make(chan os.Signal, 1)})
 		done <- true
 	}()
@@ -49,9 +50,9 @@ func TestCmdSub(t *testing.T) {
 	amqpURI := testcommon.IntegrationURIFromEnv()
 
 	done := make(chan bool)
-	receiveFunc := func(message *amqp.Delivery) error {
+	receiveFunc := func(message rabtap.TapMessage) error {
 		log.Debug("test: received message: #+v", message)
-		if string(message.Body) == testMessage {
+		if string(message.AmqpMessage.Body) == testMessage {
 			done <- true
 		}
 		return nil

cmd/rabtap/cmd_tap.go

@@ -2,8 +2,6 @@
 
 package main
 
-// subscribe cli command handler
-
 import (
 	"crypto/tls"
 	"os"

cmd/rabtap/cmd_tap_integration_test.go

@@ -24,9 +24,9 @@ func TestCmdTap(t *testing.T) {
 
 	// receiveFunc must receive messages passed through tapMessageChannel
 	done := make(chan bool)
-	receiveFunc := func(message *amqp.Delivery) error {
+	receiveFunc := func(message rabtap.TapMessage) error {
 		log.Debug("received message on tap: #+v", message)
-		if string(message.Body) == "Hello" {
+		if string(message.AmqpMessage.Body) == "Hello" {
 			done <- true
 		}
 		return nil

cmd/rabtap/default_message_formatter.go

@@ -2,12 +2,12 @@
 
 package main
 
-import "github.com/streadway/amqp"
+import rabtap "github.com/jandelgado/rabtap/pkg"
 
 // DefaultMessageFormatter is the standard message.
 type DefaultMessageFormatter struct{}
 
 // Format just returns the message body as string, no formatting applied.
-func (s DefaultMessageFormatter) Format(message *amqp.Delivery) string {
-	return string(message.Body)
+func (s DefaultMessageFormatter) Format(message rabtap.TapMessage) string {
+	return string(message.AmqpMessage.Body)
 }

cmd/rabtap/json_message_formatter.go

@@ -6,7 +6,7 @@ import (
 	"encoding/json"
 	"strings"
 
-	"github.com/streadway/amqp"
+	rabtap "github.com/jandelgado/rabtap/pkg"
 )
 
 // JSONMessageFormatter pretty prints JSON formatted messages.
@@ -22,21 +22,21 @@ var (
 // Format validates and formats a message in JSON format. The body can be a
 // simple JSON object or an array of JSON objecs. If the message is not valid
 // JSON, it will returned unformatted as-is.
-func (s JSONMessageFormatter) Format(d *amqp.Delivery) string {
+func (s JSONMessageFormatter) Format(message rabtap.TapMessage) string {
 
-	var message []byte
-	originalMessage := strings.TrimSpace(string(d.Body))
+	var formatted []byte
+	originalMessage := strings.TrimSpace(string(message.AmqpMessage.Body))
 	if originalMessage[0] == '[' {
 		// try to unmarshal array to JSON objects
 		var arrayJSONObj []map[string]interface{}
 		err := json.Unmarshal([]byte(originalMessage), &arrayJSONObj)
 		if err != nil {
-			return string(d.Body)
+			return string(message.AmqpMessage.Body)
 		}
 		// pretty print JSON
-		message, err = json.MarshalIndent(arrayJSONObj, "", "  ")
+		formatted, err = json.MarshalIndent(arrayJSONObj, "", "  ")
 		if err != nil {
-			return string(d.Body)
+			return string(message.AmqpMessage.Body)
 		}
 	} else {
 
@@ -45,13 +45,13 @@ func (s JSONMessageFormatter) Format(d *amqp.Delivery) string {
 		err := json.Unmarshal([]byte(originalMessage), &simpleJSONObj)
 
 		if err != nil {
-			return string(d.Body)
+			return string(message.AmqpMessage.Body)
 		}
 
-		message, err = json.MarshalIndent(simpleJSONObj, "", "  ")
+		formatted, err = json.MarshalIndent(simpleJSONObj, "", "  ")
 		if err != nil {
-			return string(d.Body)
+			return string(message.AmqpMessage.Body)
 		}
 	}
-	return string(message)
+	return string(formatted)
 }

cmd/rabtap/json_message_formatter_test.go

@@ -4,7 +4,9 @@ package main
 
 import (
 	"testing"
+	"time"
 
+	rabtap "github.com/jandelgado/rabtap/pkg"
 	"github.com/streadway/amqp"
 	"github.com/stretchr/testify/assert"
 )
@@ -14,7 +16,7 @@ func TestJSONFormatterInvalidArray(t *testing.T) {
 	message := amqp.Delivery{
 		Body: []byte("[ {\"a\":1} "),
 	}
-	formattedMessage := JSONMessageFormatter{}.Format(&message)
+	formattedMessage := JSONMessageFormatter{}.Format(rabtap.NewTapMessage(&message, nil, time.Now()))
 	// message is expected to be returned untouched
 	assert.Equal(t, "[ {\"a\":1} ", formattedMessage)
 }
@@ -24,7 +26,7 @@ func TestJSONFormatterValidArray(t *testing.T) {
 	message := amqp.Delivery{
 		Body: []byte(" [   {\"a\":1}    ] "),
 	}
-	formattedMessage := JSONMessageFormatter{}.Format(&message)
+	formattedMessage := JSONMessageFormatter{}.Format(rabtap.NewTapMessage(&message, nil, time.Now()))
 	assert.Equal(t, "[\n  {\n    \"a\": 1\n  }\n]", formattedMessage)
 }
 
@@ -33,7 +35,7 @@ func TestJSONFormatterInvalidObject(t *testing.T) {
 	message := amqp.Delivery{
 		Body: []byte("[ {\"a\":1 "),
 	}
-	formattedMessage := JSONMessageFormatter{}.Format(&message)
+	formattedMessage := JSONMessageFormatter{}.Format(rabtap.NewTapMessage(&message, nil, time.Now()))
 	// message is expected to be returned untouched
 	assert.Equal(t, "[ {\"a\":1 ", formattedMessage)
 }
@@ -43,6 +45,6 @@ func TestJSONFormatterValidObject(t *testing.T) {
 	message := amqp.Delivery{
 		Body: []byte("  {\"a\":1}   "),
 	}
-	formattedMessage := JSONMessageFormatter{}.Format(&message)
+	formattedMessage := JSONMessageFormatter{}.Format(rabtap.NewTapMessage(&message, nil, time.Now()))
 	assert.Equal(t, "{\n  \"a\": 1\n}", formattedMessage)
 }

cmd/rabtap/message_printer.go

@@ -1,49 +1,44 @@
-// Copyright (C) 2017 Jan Delgado
+// Copyright (C) 2017-2019 Jan Delgado
 
 package main
 
 import (
-	"encoding/json"
 	"io"
 	"text/template"
 
-	"github.com/streadway/amqp"
+	rabtap "github.com/jandelgado/rabtap/pkg"
 )
 
 // messageTemplate is the default template to print a message
-const messageTemplate = `------ {{ .Title }} ------
-exchange.......: {{ ExchangeColor .Message.Exchange }}
-{{with .Message.RoutingKey}}routingkey.....: {{ KeyColor .}}
-{{end}}{{with .Message.Priority}}priority.......: {{.}}
-{{end}}{{with .Message.Expiration}}expiration.....: {{.}}
-{{end}}{{with .Message.ContentType}}content-type...: {{.}}
-{{end}}{{with .Message.ContentEncoding}}content-enc....: {{.}}
-{{end}}{{with .Message.MessageId}}app-message-id.: {{.}}
-{{end}}{{if not .Message.Timestamp.IsZero}}app-timestamp..: {{ .Message.Timestamp }}
-{{end}}{{with .Message.Type}}app-type.......: {{.}}
-{{end}}{{with .Message.CorrelationId}}app-corr-id....: {{.}}
-{{end}}{{with .Message.Headers}}app-headers....: {{.}}
+// TODO allow externalization of template
+const messageTemplate = `------ message received on {{ .Message.ReceivedTimestamp.Format "2006-01-02T15:04:05Z07:00" }} ------
+exchange.......: {{ ExchangeColor .Message.AmqpMessage.Exchange }}
+{{with .Message.AmqpMessage.RoutingKey}}routingkey.....: {{ KeyColor .}}
+{{end}}{{with .Message.AmqpMessage.Priority}}priority.......: {{.}}
+{{end}}{{with .Message.AmqpMessage.Expiration}}expiration.....: {{.}}
+{{end}}{{with .Message.AmqpMessage.ContentType}}content-type...: {{.}}
+{{end}}{{with .Message.AmqpMessage.ContentEncoding}}content-enc....: {{.}}
+{{end}}{{with .Message.AmqpMessage.MessageId}}app-message-id.: {{.}}
+{{end}}{{if not .Message.AmqpMessage.Timestamp.IsZero}}app-timestamp..: {{ .Message.AmqpMessage.Timestamp }}
+{{end}}{{with .Message.AmqpMessage.Type}}app-type.......: {{.}}
+{{end}}{{with .Message.AmqpMessage.CorrelationId}}app-corr-id....: {{.}}
+{{end}}{{with .Message.AmqpMessage.Headers}}app-headers....: {{.}}
 {{end -}}
 {{ MessageColor .Body }}
 
 `
 
 // PrintMessageInfo holds info for template
 type PrintMessageInfo struct {
-	// Title to print
-	Title string
 	// Message receveived
-	Message amqp.Delivery
+	Message rabtap.TapMessage
 	// formatted body
 	Body string
-	// formatted headers
-	Headers string
 }
 
-// MessageFormatter formats the body of ampq.Delivery objects according to its
-// type
+// MessageFormatter formats the body of tapped message
 type MessageFormatter interface {
-	Format(message *amqp.Delivery) string
+	Format(message rabtap.TapMessage) string
 }
 
 // Registry of available message formatters. Key is contentType
@@ -55,36 +50,26 @@ func RegisterMessageFormatter(contentType string, formatter MessageFormatter) {
 	messageFormatters[contentType] = formatter
 }
 
-// NewMessageFormatter return a message formatter suitable for the given
-// message type, determined by the message headers content type.
-func NewMessageFormatter(message *amqp.Delivery) MessageFormatter {
-	if formatter, ok := messageFormatters[message.ContentType]; ok {
+// NewMessageFormatter return a message formatter suitable the given
+// contentType.
+func NewMessageFormatter(contentType string) MessageFormatter {
+	if formatter, ok := messageFormatters[contentType]; ok {
 		return formatter
 	}
 	return DefaultMessageFormatter{}
 }
 
-// PrettyPrintMessage formats and prints a amqp.Delivery message
-func PrettyPrintMessage(out io.Writer, message *amqp.Delivery,
-	title string, noColor bool) error {
+// PrettyPrintMessage formats and prints a tapped message
+func PrettyPrintMessage(out io.Writer, message rabtap.TapMessage,
+	noColor bool) error {
 
 	colorizer := NewColorPrinter(noColor)
 
-	// get mesagge formatter according to message type
-	formatter := NewMessageFormatter(message)
+	formatter := NewMessageFormatter(message.AmqpMessage.ContentType)
 
-	// nicely print headers as JSON for better readability
-	headers, err := json.Marshal(message.Headers)
-	if err != nil {
-		return err
-	}
-
-	body := formatter.Format(message)
 	printStruct := PrintMessageInfo{
-		Title:   title,
-		Message: *message,
-		Body:    body,
-		Headers: string(headers),
+		Message: message,
+		Body:    formatter.Format(message),
 	}
 	t := template.Must(template.New("message").
 		Funcs(colorizer.GetFuncMap()).Parse(messageTemplate))

cmd/rabtap/message_printer_test.go

@@ -1,4 +1,4 @@
-// Copyright (C) 2017 Jan Delgado
+// Copyright (C) 2017-2019 Jan Delgado
 
 package main
 
@@ -7,16 +7,17 @@ import (
 	"testing"
 	"time"
 
+	rabtap "github.com/jandelgado/rabtap/pkg"
 	"github.com/streadway/amqp"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestNewMessageFormatter(t *testing.T) {
 
 	assert.Equal(t, JSONMessageFormatter{},
-		NewMessageFormatter(&amqp.Delivery{ContentType: "application/json"}))
+		NewMessageFormatter("application/json"))
 	assert.Equal(t, DefaultMessageFormatter{},
-		NewMessageFormatter(&amqp.Delivery{ContentType: "unknown"}))
+		NewMessageFormatter("unknown"))
 }
 
 func ExamplePrettyPrintMessage() {
@@ -36,10 +37,12 @@ func ExamplePrettyPrintMessage() {
 		Body:            []byte("simple test message"),
 	}
 
-	_ = PrettyPrintMessage(os.Stdout, &message, "title", true)
+	ts := time.Date(2019, time.June, 6, 23, 0, 0, 0, time.UTC)
+	noColor := true
+	_ = PrettyPrintMessage(os.Stdout, rabtap.NewTapMessage(&message, nil, ts), noColor)
 
 	// Output:
-	// ------ title ------
+	// ------ message received on 2019-06-06T23:00:00Z ------
 	// exchange.......: exchange
 	// routingkey.....: routingkey
 	// priority.......: 99
@@ -62,10 +65,12 @@ func ExamplePrettyPrintMessage_withFilteredAtributes() {
 		Body:     []byte("simple test message"),
 	}
 
-	_ = PrettyPrintMessage(os.Stdout, &message, "title", true)
+	noColor := true
+	ts := time.Date(2019, time.June, 6, 23, 0, 0, 0, time.UTC)
+	_ = PrettyPrintMessage(os.Stdout, rabtap.NewTapMessage(&message, nil, ts), noColor)
 
 	// Output:
-	// ------ title ------
+	// ------ message received on 2019-06-06T23:00:00Z ------
 	// exchange.......: exchange
 	// simple test message
 	//