feat: add ability to update pipeline topic list at runtime.

internal/app/service.go

@@ -404,33 +404,36 @@ func (svc *Service) SetDefaultFunctionsPipeline(transforms ...interfaces.AppFunc
 	return nil
 }
 
-// AddFunctionsPipelineForTopics adds a functions pipeline for the specified for the specified id and topics
-func (svc *Service) AddFunctionsPipelineForTopics(id string, topics []string, transforms ...interfaces.AppFunction) error {
-	if len(transforms) == 0 {
-		return errors.New("no transforms provided to pipeline")
-	}
+// getFullTopics adds the base topic prefix to all the topics in a list
+func getFullTopics(topics []string, baseTopicPrefix string) ([]string, error) {
+	var fullTopics []string
 
 	if len(topics) == 0 {
-		return errors.New("topics for pipeline can not be empty")
+		return nil, errors.New("topics for pipeline can not be empty")
 	}
 
-	for _, t := range topics {
-		if strings.TrimSpace(t) == "" {
-			return errors.New("blank topic not allowed")
+	for _, topic := range topics {
+		if strings.TrimSpace(topic) == "" {
+			return nil, errors.New("blank topic not allowed")
 		}
+		fullTopics = append(fullTopics, coreCommon.BuildTopic(baseTopicPrefix, topic))
 	}
+	return fullTopics, nil
+}
 
-	// Must add the base topic to all the input topics
-	var fullTopics []string
-	for _, topic := range topics {
-		fullTopics = append(fullTopics, coreCommon.BuildTopic(svc.config.MessageBus.GetBaseTopicPrefix(), topic))
+// AddFunctionsPipelineForTopics adds a functions pipeline for the specified for the specified id and topics
+func (svc *Service) AddFunctionsPipelineForTopics(id string, topics []string, transforms ...interfaces.AppFunction) error {
+	if len(transforms) == 0 {
+		return errors.New("no transforms provided to pipeline")
 	}
-
-	err := svc.runtime.AddFunctionsPipeline(id, fullTopics, transforms)
+	fullTopics, err := getFullTopics(topics, svc.config.MessageBus.GetBaseTopicPrefix())
+	if err != nil {
+		return err
+	}
+	err = svc.runtime.AddFunctionsPipeline(id, fullTopics, transforms)
 	if err != nil {
 		return err
 	}
-
 	svc.lc.Debugf("Pipeline '%s' added for topics '%v' with %d transform(s)", id, fullTopics, len(transforms))
 	return nil
 }
@@ -440,6 +443,16 @@ func (svc *Service) RemoveAllFunctionPipelines() {
 	svc.runtime.RemoveAllFunctionPipelines()
 }
 
+// SetFunctionsPipelineTopics updates the list of topics for the specified functions pipeline
+func (svc *Service) SetFunctionsPipelineTopics(id string, topics []string) error {
+	fullTopics, err := getFullTopics(topics, svc.config.MessageBus.GetBaseTopicPrefix())
+	if err != nil {
+		return err
+	}
+	svc.runtime.SetFunctionsPipelineTopics(id, fullTopics)
+	return nil
+}
+
 // RequestTimeout returns the Request Timeout duration that was parsed from the Service.RequestTimeout configuration
 func (svc *Service) RequestTimeout() time.Duration {
 	return svc.requestTimeout

internal/app/service_test.go

@@ -393,6 +393,44 @@ func TestService_AddFunctionsPipelineForTopics(t *testing.T) {
 	}
 }
 
+func TestService_SetFunctionsPipelineTopics(t *testing.T) {
+	service := Service{
+		lc:      lc,
+		dic:     dic,
+		runtime: runtime.NewFunctionPipelineRuntime("", nil, dic),
+		config: &common.ConfigurationStruct{
+			Trigger: common.TriggerInfo{
+				Type: TriggerTypeMessageBus,
+			},
+			MessageBus: config.MessageBusInfo{
+				BaseTopicPrefix: "base/two",
+			},
+		},
+	}
+
+	tags := builtin.NewTags(nil)
+
+	transforms := []interfaces.AppFunction{tags.AddTags}
+	topics := []string{"a/b", "a/c"}
+	bustopics := []string{"base/two/a/b", "base/two/a/c"}
+	err := service.AddFunctionsPipelineForTopics("pl", topics, transforms...)
+	require.NoError(t, err)
+	assert.Equal(t, bustopics, service.runtime.GetPipelineById("pl").Topics)
+
+	topics = append(topics, "c/d/e")
+	bustopics = append(bustopics, "base/two/c/d/e")
+	err = service.SetFunctionsPipelineTopics("pl", topics)
+	require.NoError(t, err)
+	assert.Equal(t, bustopics, service.runtime.GetPipelineById("pl").Topics)
+	err = service.SetFunctionsPipelineTopics("pl", nil)
+	require.Error(t, err)
+	assert.Equal(t, bustopics, service.runtime.GetPipelineById("pl").Topics)
+	topics = append(topics, "")
+	err = service.SetFunctionsPipelineTopics("pl", topics)
+	require.Error(t, err)
+	assert.Equal(t, bustopics, service.runtime.GetPipelineById("pl").Topics)
+}
+
 func TestService_RemoveAllFunctionPipelines(t *testing.T) {
 	service := Service{
 		lc:      lc,

pkg/interfaces/service.go

@@ -117,6 +117,8 @@ type ApplicationService interface {
 	AddFunctionsPipelineForTopics(id string, topic []string, transforms ...AppFunction) error
 	// RemoveAllFunctionPipelines removes all existing function pipelines
 	RemoveAllFunctionPipelines()
+	// SetFunctionsPipelineTopics updates the list of topics for the specified functions pipeline
+	SetFunctionsPipelineTopics(id string, topics []string) error
 	// Run starts the configured trigger to allow the functions pipeline to execute when the trigger
 	// receives data and starts the internal webserver. This is a long-running function which does not return until
 	// the service is stopped or Stop() is called.