Add topic metadata for mqtt input binding and support user defined topic for mqtt output binding (#1674)

* feat(bindings/mqtt): add data incoming topic to metadata

Signed-off-by: lotuc <lotu.c@outlook.com>

* feat(bindings/mqtt): support user defined topic on create action

Signed-off-by: lotuc <lotu.c@outlook.com>

* chore(bindings/mqtt): add integration test and topic response check test

Signed-off-by: lotuc <lotu.c@outlook.com>

* fix(bindings/mqtt): ignore misspell linting error for word mosquitto

Signed-off-by: lotuc <lotu.c@outlook.com>

Co-authored-by: Yaron Schneider <schneider.yaron@live.com>

bindings/mqtt/mqtt.go

@@ -204,8 +204,13 @@ func (m *MQTT) Invoke(ctx context.Context, req *bindings.InvokeRequest) (*bindin
 	bo = backoff.WithContext(bo, ctx)
 
 	return nil, retry.NotifyRecover(func() error {
-		m.logger.Debugf("mqtt publishing topic %s with data: %v", m.metadata.topic, req.Data)
+		topic, ok := req.Metadata[mqttTopic]
-		token := m.producer.Publish(m.metadata.topic, m.metadata.qos, m.metadata.retain, req.Data)
+		if !ok || topic == "" {
+			// If user does not specify a topic, publish via the component's default topic.
+			topic = m.metadata.topic
+		}
+		m.logger.Debugf("mqtt publishing topic %s with data: %v", topic, req.Data)
+		token := m.producer.Publish(topic, m.metadata.qos, m.metadata.retain, req.Data)
 		if !token.WaitTimeout(defaultWait) || token.Error() != nil {
 			return fmt.Errorf("mqtt error from publish: %v", token.Error())
 		}
@@ -218,7 +223,10 @@ func (m *MQTT) Invoke(ctx context.Context, req *bindings.InvokeRequest) (*bindin
 }
 
 func (m *MQTT) handleMessage(handler func(context.Context, *bindings.ReadResponse) ([]byte, error), mqttMsg mqtt.Message) error {
-	msg := bindings.ReadResponse{Data: mqttMsg.Payload()}
+	msg := bindings.ReadResponse{
+		Data:     mqttMsg.Payload(),
+		Metadata: map[string]string{mqttTopic: mqttMsg.Topic()},
+	}
 
 	// paho.mqtt.golang requires that handlers never block or it can deadlock on client.Disconnect.
 	// To ensure that the Dapr runtime does not hang on teardown on of the component, run the app's

bindings/mqtt/mqtt_integration_test.go

@@ -0,0 +1,114 @@
+package mqtt
+
+import (
+	"context"
+	"os"
+	"testing"
+	"time"
+
+	mqtt "github.com/eclipse/paho.mqtt.golang"
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+
+	"github.com/dapr/components-contrib/bindings"
+	"github.com/dapr/kit/logger"
+)
+
+const (
+	// Environment variable containing the host name for MQTT integration tests
+	// To run using docker:
+	//   Create mosquitto.conf with content:
+	//     listener 1883
+	//     allow_anonymous true
+	//   And run:
+	// nolint:misspell
+	//     docker run -d -v mosquitto.conf:/mosquitto/config/mosquitto.conf --name test-mqtt -p 1883:1883 eclipse-mosquitto:2
+	// In that case the connection string will be: tcp://127.0.0.1:1883
+	testMQTTConnectionStringEnvKey = "DAPR_TEST_MQTT_URL"
+)
+
+func getConnectionString() string {
+	return os.Getenv(testMQTTConnectionStringEnvKey)
+}
+
+func TestInvokeWithTopic(t *testing.T) {
+	t.Parallel()
+
+	url := getConnectionString()
+	if url == "" {
+		t.Skipf("MQTT connection string configuration must be set in environment variable '%s' (example 'tcp://localhost:1883')", testMQTTConnectionStringEnvKey)
+	}
+
+	topicDefault := "/app/default"
+	const msgDefault = "hello from default"
+	dataDefault := []byte(msgDefault)
+
+	topicCustomized := "/app/customized"
+	const msgCustomized = "hello from customized"
+	dataCustomized := []byte(msgCustomized)
+
+	metadata := bindings.Metadata{
+		Name: "testQueue",
+		Properties: map[string]string{
+			"consumerID":        uuid.NewString(),
+			"url":               url,
+			"topic":             topicDefault,
+			"qos":               "1",
+			"retain":            "false",
+			"cleanSession":      "true",
+			"backOffMaxRetries": "0",
+		},
+	}
+
+	logger := logger.NewLogger("test")
+
+	r := NewMQTT(logger)
+	err := r.Init(metadata)
+	assert.Nil(t, err)
+
+	conn, err := r.connect(uuid.NewString())
+	assert.Nil(t, err)
+	defer conn.Disconnect(1)
+
+	msgCh := make(chan interface{})
+	defer close(msgCh)
+
+	token := conn.Subscribe("/app/#", 1, func(client mqtt.Client, mqttMsg mqtt.Message) {
+		msgCh <- mqttMsg
+	})
+	ok := token.WaitTimeout(2 * time.Second)
+	assert.True(t, ok, "subscribe to /app/# timeout")
+	err = token.Error()
+	assert.Nil(t, err, "error subscribe to test topic")
+
+	// Timeout in case message transfer error.
+	go func() {
+		time.Sleep(5 * time.Second)
+		msgCh <- "timeout"
+	}()
+
+	// Test invoke with default topic configured for component.
+	_, err = r.Invoke(context.TODO(), &bindings.InvokeRequest{Data: dataDefault})
+	assert.Nil(t, err)
+
+	m := <-msgCh
+	mqttMessage, ok := m.(mqtt.Message)
+	assert.True(t, ok)
+	assert.Equal(t, dataDefault, mqttMessage.Payload())
+	assert.Equal(t, topicDefault, mqttMessage.Topic())
+
+	// Test invoke with customized topic.
+	_, err = r.Invoke(context.TODO(), &bindings.InvokeRequest{
+		Data: dataCustomized,
+		Metadata: map[string]string{
+			mqttTopic: topicCustomized,
+		},
+	})
+	assert.Nil(t, err)
+
+	m = <-msgCh
+	mqttMessage, ok = m.(mqtt.Message)
+	assert.True(t, ok)
+	assert.Equal(t, dataCustomized, mqttMessage.Payload())
+	assert.Equal(t, topicCustomized, mqttMessage.Topic())
+}

bindings/mqtt/mqtt_test.go

@@ -14,6 +14,7 @@ limitations under the License.
 package mqtt
 
 import (
+	"context"
 	"crypto/x509"
 	"encoding/pem"
 	"errors"
@@ -22,6 +23,7 @@ import (
 	"github.com/stretchr/testify/assert"
 
 	"github.com/dapr/components-contrib/bindings"
+	"github.com/dapr/kit/logger"
 )
 
 func getFakeProperties() map[string]string {
@@ -187,4 +189,74 @@ func TestParseMetadata(t *testing.T) {
 		assert.NoError(t, err)
 		assert.NotNil(t, m.tlsCfg.clientKey, "failed to parse valid client certificate key")
 	})
+
+	t.Run("Response returns the topic that the subscribed data is from.", func(t *testing.T) {
+		const msg = "hello world"
+
+		payload := []byte(msg)
+		topic := "/topic/where/the/data/is/from"
+
+		logger := logger.NewLogger("test")
+		m := NewMQTT(logger)
+		m.ctx, m.cancel = context.WithCancel(context.Background())
+
+		m.handleMessage(func(ctx context.Context, r *bindings.ReadResponse) ([]byte, error) {
+			assert.Equal(t, payload, r.Data)
+			metadata := r.Metadata
+			responseTopic, ok := metadata[mqttTopic]
+			assert.True(t, ok)
+			assert.Equal(t, topic, responseTopic)
+			return r.Data, nil
+		}, &mqttMockMessage{
+			topic:   topic,
+			payload: payload,
+		})
+	})
+}
+
+type mqttMockMessage struct {
+	duplicate         bool
+	qos               byte
+	retained          bool
+	topic             string
+	mqttMockMessageID uint16
+	payload           []byte
+	ackCalled         bool
+	noautoack         bool
+}
+
+func (m *mqttMockMessage) Duplicate() bool {
+	return m.duplicate
+}
+
+func (m *mqttMockMessage) Qos() byte {
+	return m.qos
+}
+
+func (m *mqttMockMessage) Retained() bool {
+	return m.retained
+}
+
+func (m *mqttMockMessage) Topic() string {
+	return m.topic
+}
+
+func (m *mqttMockMessage) MessageID() uint16 {
+	return m.mqttMockMessageID
+}
+
+func (m *mqttMockMessage) Payload() []byte {
+	return m.payload
+}
+
+func (m *mqttMockMessage) Ack() {
+	m.ackCalled = true
+}
+
+func (m *mqttMockMessage) NoAutoAck() bool {
+	return m.noautoack
+}
+
+func (m *mqttMockMessage) AutoAckOff() {
+	m.noautoack = true
 }