[#18] MessageHandler interface enhancements

Fixed PR review comments.
- CloudConnectionInfo renamed to RemoteConnectionInfo
- SharedAccessKey struct removed, not really needed (SharedAccessKeyName is not applicable for Azure IoT Hub device connection string.
- SharedAccessKey is now just a []byte field.

Signed-off-by: Stoyan Zoubev <[email protected]>

cmd/azure-connector/app/launch.go

@@ -71,10 +71,10 @@ func startRouter(
 	azureSub := connector.NewSubscriber(azureClient, connector.QosAtMostOnce, false, logger, nil)
 	mosquittoSub := connector.NewSubscriber(cloudClient, connector.QosAtLeastOnce, false, router.Logger(), nil)
 
-	routingbus.TelemetryBus(router, azurePub, mosquittoSub, &connSettings.CloudConnectionInfo, telemetryHandlers)
+	routingbus.TelemetryBus(router, azurePub, mosquittoSub, &connSettings.RemoteConnectionInfo, telemetryHandlers)
 
 	cloudPub := connector.NewPublisher(cloudClient, connector.QosAtLeastOnce, router.Logger(), nil)
-	routingbus.CommandBus(router, cloudPub, azureSub, &connSettings.CloudConnectionInfo, commandHandlers)
+	routingbus.CommandBus(router, cloudPub, azureSub, &connSettings.RemoteConnectionInfo, commandHandlers)
 
 	go func() {
 		ctx, cancel := context.WithCancel(context.Background())

config/connection_settings.go

@@ -30,36 +30,29 @@ import (
 )
 
 const (
-	provisioningJSONConfig         = "provisioning.json" // TODO: why with the same name as default flag value?
-	hostNameSuffix                 = ".azure-devices.net"
-	propertyKeyHostName            = "HostName"
-	propertyKeyDeviceID            = "DeviceId"
-	propertyKeySharedAccessKey     = "SharedAccessKey"
-	propertyKeySharedAccessKeyName = "SharedAccessKeyName"
+	provisioningJSONConfig     = "provisioning.json" // TODO: why with the same name as default flag value?
+	hostNameSuffix             = ".azure-devices.net"
+	propertyKeyHostName        = "HostName"
+	propertyKeyDeviceID        = "DeviceId"
+	propertyKeySharedAccessKey = "SharedAccessKey"
 )
 
-// CloudConnectionInfo contains properties related to the cloud connection that may not be known at the start of the connector.
-type CloudConnectionInfo struct {
+// RemoteConnectionInfo contains properties related to the cloud connection that may not be known at the start of the connector.
+type RemoteConnectionInfo struct {
 	HubName  string
 	HostName string
 	DeviceID string
 }
 
-// SharedAccessKey contains the shared access key for generating SAS token for device authentication.
-type SharedAccessKey struct {
-	SharedAccessKeyName    string
-	SharedAccessKeyDecoded []byte
-}
-
 // AzureConnectionSettings contains the configuration data for establishing connection to the Azure IoT Hub.
 type AzureConnectionSettings struct {
-	CloudConnectionInfo
+	RemoteConnectionInfo
 
 	DeviceCert    string
 	DeviceKey     string
 	TokenValidity time.Duration
 
-	*SharedAccessKey
+	SharedAccessKey []byte
 }
 
 // PrepareAzureConnectionSettings prepares the configuration data for establishing connection to the Azure IoT Hub, allowing usage of IDScopeProvider.
@@ -220,10 +213,7 @@ func CreateAzureSASTokenConnectionSettings(
 	if sharedAccessKeyDecoded, err = base64.StdEncoding.DecodeString(sharedAccessKey); err != nil {
 		return nil, errors.New("the SharedAccessKey is not base64 encoded")
 	}
-	connSettings.SharedAccessKey = &SharedAccessKey{
-		SharedAccessKeyName:    connStringProperties[propertyKeySharedAccessKeyName],
-		SharedAccessKeyDecoded: sharedAccessKeyDecoded,
-	}
+	connSettings.SharedAccessKey = sharedAccessKeyDecoded
 
 	if tokenValidity, err := ParseSASTokenValidity(settings.SASTokenValidity); err != nil {
 		logger.Warn("The default SAS token validity period will be set.", err, nil)

config/connection_settings_test.go

@@ -60,8 +60,7 @@ func TestCreateTokenConnectionSettings(t *testing.T) {
 	assert.Equal(t, "dummy-device", connSettings.DeviceID)
 	assert.Equal(t, "dummy-hub.azure-devices.net", connSettings.HostName)
 	assert.Equal(t, "dummy-hub", connSettings.HubName)
-	assert.Equal(t, "", connSettings.SharedAccessKey.SharedAccessKeyName)
-	assert.Equal(t, decodedSharedAccessKey, connSettings.SharedAccessKey.SharedAccessKeyDecoded)
+	assert.Equal(t, decodedSharedAccessKey, connSettings.SharedAccessKey)
 	assert.Equal(t, time.Hour, connSettings.TokenValidity)
 	assert.Equal(t, "", connSettings.DeviceCert)
 	assert.Equal(t, "", connSettings.DeviceKey)

config/connections_test.go

@@ -31,17 +31,15 @@ func TestCreateAzureClientNoCacert(t *testing.T) {
 	defer goleak.VerifyNone(t)
 
 	decodedAccessKey, _ := base64.StdEncoding.DecodeString("x7HrdC+URzEneFam9ZKa0Ke7nvsDwiuJptzFkgs8JWA=")
-	accessKey := &config.SharedAccessKey{
-		SharedAccessKeyDecoded: decodedAccessKey,
-	}
+
 	settings := &config.AzureSettings{}
 	connSettings := &config.AzureConnectionSettings{
-		CloudConnectionInfo: config.CloudConnectionInfo{
+		RemoteConnectionInfo: config.RemoteConnectionInfo{
 			DeviceID: "dummy-device",
 			HostName: "dummy-hub.azure-devices.net",
 			HubName:  "dummy-hub",
 		},
-		SharedAccessKey: accessKey,
+		SharedAccessKey: decodedAccessKey,
 	}
 
 	logger := logger.NewLogger(log.New(io.Discard, "", log.Ldate), logger.INFO)

config/sas.go

@@ -39,35 +39,28 @@ type SharedAccessSignature struct {
 	Sr  string
 	Sig string
 	Se  time.Time
-	Skn string
 }
 
 // GenerateSASToken generates the SAS token for device authentication.
 func GenerateSASToken(connSettings *AzureConnectionSettings) *SharedAccessSignature {
 	return newSharedAccessSignature(connSettings.HostName,
-		connSettings.SharedAccessKeyName,
-		connSettings.SharedAccessKey.SharedAccessKeyDecoded,
+		connSettings.SharedAccessKey,
 		Now().Add(connSettings.TokenValidity))
 }
 
 func sasTokenToString(sas *SharedAccessSignature) string {
-	s := "SharedAccessSignature " +
+	return "SharedAccessSignature " +
 		"sr=" + url.QueryEscape(sas.Sr) +
 		"&sig=" + url.QueryEscape(sas.Sig) +
 		"&se=" + url.QueryEscape(strconv.FormatInt(sas.Se.Unix(), 10))
-	if sas.Skn != "" {
-		s += "&skn=" + url.QueryEscape(sas.Skn)
-	}
-	return s
 }
 
-func newSharedAccessSignature(resource, policy string, decodedKey []byte, expiry time.Time) *SharedAccessSignature {
+func newSharedAccessSignature(resource string, decodedKey []byte, expiry time.Time) *SharedAccessSignature {
 	sig := messageKeySignature(resource, decodedKey, expiry)
 	return &SharedAccessSignature{
 		Sr:  resource,
 		Sig: sig,
 		Se:  expiry,
-		Skn: policy,
 	}
 }
 

config/sas_test.go

@@ -39,7 +39,6 @@ func TestGenerateSASToken(t *testing.T) {
 
 	sasToken := config.GenerateSASToken(connSettings)
 
-	assert.Equal(t, "", sasToken.Skn)
 	assert.Equal(t, "dummy-hub.azure-devices.net", sasToken.Sr)
 	assert.Equal(t, "2021-01-01 01:00:00 +0000 UTC", sasToken.Se.String())
 	assert.Equal(t, "ifZm2I0YKRkwc8Pc49e0qKSsu3l3FbxoWZRqGBtXtng=", sasToken.Sig)

routing/bus/command.go

@@ -37,7 +37,7 @@ type commandBusHandler struct {
 func CommandBus(router *message.Router,
 	mosquittoPub message.Publisher,
 	azureSub message.Subscriber,
-	connInfo *config.CloudConnectionInfo,
+	connInfo *config.RemoteConnectionInfo,
 	commandHandlers []handlers.CommandHandler,
 ) {
 	//Azure IoT Hub -> Message bus -> Mosquitto Broker -> Gateway

routing/bus/internal/testing/utils.go

@@ -53,7 +53,7 @@ type dummyMessageHandler struct {
 	handleErr  error
 }
 
-func (h *dummyMessageHandler) Init(connInfo *config.CloudConnectionInfo) error {
+func (h *dummyMessageHandler) Init(connInfo *config.RemoteConnectionInfo) error {
 	return h.initErr
 }
 

routing/bus/telemetry.go

@@ -26,7 +26,7 @@ func TelemetryBus(
 	router *message.Router,
 	azurePub message.Publisher,
 	mosquittoSub message.Subscriber,
-	connInfo *config.CloudConnectionInfo,
+	connInfo *config.RemoteConnectionInfo,
 	telemetryHandlers []handlers.TelemetryHandler,
 ) {
 	//Gateway -> Mosquitto Broker -> Message bus -> Azure IoT Hub

routing/bus/telemetry_test.go

@@ -98,8 +98,8 @@ func TestTelemetryMessageHandlerInitializationError(t *testing.T) {
 	test.AssertNoRouterHandlers(t, router)
 }
 
-func setupTestRouter(deviceID string) (*message.Router, *config.CloudConnectionInfo) {
-	connInfo := &config.CloudConnectionInfo{
+func setupTestRouter(deviceID string) (*message.Router, *config.RemoteConnectionInfo) {
+	connInfo := &config.RemoteConnectionInfo{
 		DeviceID: deviceID,
 	}
 	router, _ := message.NewRouter(message.RouterConfig{}, watermill.NopLogger{})

routing/message/handlers/handler.go

@@ -19,7 +19,7 @@ import (
 
 // MessageHandler represents the internal interface for implementing a message handler.
 type messageHandler interface {
-	Init(connInfo *config.CloudConnectionInfo) error
+	Init(connInfo *config.RemoteConnectionInfo) error
 	HandleMessage(message *message.Message) ([]*message.Message, error)
 	Name() string
 }

routing/message/handlers/passthrough/command_handler.go

@@ -36,7 +36,7 @@ func CreateCommandHandler(topic string) handlers.CommandHandler {
 }
 
 // Init does nothing.
-func (h *commandHandler) Init(connInfo *config.CloudConnectionInfo) error {
+func (h *commandHandler) Init(connInfo *config.RemoteConnectionInfo) error {
 	return nil
 }
 

routing/message/handlers/passthrough/telemetry_handler.go

@@ -40,7 +40,7 @@ func CreateTelemetryHandler(topics string) handlers.TelemetryHandler {
 }
 
 // Init gets the device ID that is needed for the message forwarding towards Azure IoT Hub.
-func (h *telemetryHandler) Init(connInfo *config.CloudConnectionInfo) error {
+func (h *telemetryHandler) Init(connInfo *config.RemoteConnectionInfo) error {
 	h.deviceID = connInfo.DeviceID
 	return nil
 }

routing/message/handlers/passthrough/telemetry_handler_test.go

@@ -33,7 +33,7 @@ func TestCreateTelemetryHandler(t *testing.T) {
 
 func TestHandleTelemetryMessage(t *testing.T) {
 	handler := CreateTelemetryHandler("telemetry_topic")
-	require.NoError(t, handler.Init(&config.CloudConnectionInfo{DeviceID: "dummy_device"}))
+	require.NoError(t, handler.Init(&config.RemoteConnectionInfo{DeviceID: "dummy_device"}))
 
 	payload := "dummy_message"
 	outgoingMessages, err := handler.HandleMessage(&message.Message{Payload: []byte(payload)})