Simplify builders for components, remove unnecessary builders (open-t…

…elemetry#2624)

Signed-off-by: Bogdan Drutu <bogdandrutu@gmail.com>

service/builder/exporters_builder.go

@@ -140,32 +140,28 @@ type dataTypeRequirements map[configmodels.DataType]dataTypeRequirement
 // Data type requirements for all exporters.
 type exportersRequiredDataTypes map[configmodels.Exporter]dataTypeRequirements
 
-// ExportersBuilder builds exporters from config.
-type ExportersBuilder struct {
+// exportersBuilder builds exporters from config.
+type exportersBuilder struct {
 	logger    *zap.Logger
 	appInfo   component.ApplicationStartInfo
 	config    *configmodels.Config
 	factories map[configmodels.Type]component.ExporterFactory
 }
 
-// NewExportersBuilder creates a new ExportersBuilder. Call BuildExporters() on the returned value.
-func NewExportersBuilder(
+// BuildExporters builds Exporters from config.
+func BuildExporters(
 	logger *zap.Logger,
 	appInfo component.ApplicationStartInfo,
 	config *configmodels.Config,
 	factories map[configmodels.Type]component.ExporterFactory,
-) *ExportersBuilder {
-	return &ExportersBuilder{logger.With(zap.String(kindLogKey, kindLogsExporter)), appInfo, config, factories}
-}
-
-// BuildExporters exporters from config.
-func (eb *ExportersBuilder) Build() (Exporters, error) {
-	exporters := make(Exporters)
+) (Exporters, error) {
+	eb := &exportersBuilder{logger.With(zap.String(kindLogKey, kindLogsExporter)), appInfo, config, factories}
 
 	// We need to calculate required input data types for each exporter so that we know
 	// which data type must be started for each exporter.
 	exporterInputDataTypes := eb.calcExportersRequiredDataTypes()
 
+	exporters := make(Exporters)
 	// BuildExporters exporters based on configuration and required input data types.
 	for _, cfg := range eb.config.Exporters {
 		componentLogger := eb.logger.With(zap.String(typeLogKey, string(cfg.Type())), zap.String(nameLogKey, cfg.Name()))
@@ -180,7 +176,7 @@ func (eb *ExportersBuilder) Build() (Exporters, error) {
 	return exporters, nil
 }
 
-func (eb *ExportersBuilder) calcExportersRequiredDataTypes() exportersRequiredDataTypes {
+func (eb *exportersBuilder) calcExportersRequiredDataTypes() exportersRequiredDataTypes {
 
 	// Go over all pipelines. The data type of the pipeline defines what data type
 	// each exporter is expected to receive. Collect all required types for each
@@ -213,7 +209,7 @@ func (eb *ExportersBuilder) calcExportersRequiredDataTypes() exportersRequiredDa
 	return result
 }
 
-func (eb *ExportersBuilder) buildExporter(
+func (eb *exportersBuilder) buildExporter(
 	ctx context.Context,
 	logger *zap.Logger,
 	appInfo component.ApplicationStartInfo,

service/builder/exporters_builder_test.go

@@ -61,7 +61,7 @@ func TestExportersBuilder_Build(t *testing.T) {
 		},
 	}
 
-	exporters, err := NewExportersBuilder(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, factories.Exporters).Build()
+	exporters, err := BuildExporters(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, factories.Exporters)
 
 	assert.NoError(t, err)
 	require.NotNil(t, exporters)
@@ -90,7 +90,7 @@ func TestExportersBuilder_Build(t *testing.T) {
 	// This should result in creating an exporter that has none of consumption
 	// functions set.
 	delete(cfg.Service.Pipelines, "trace")
-	exporters, err = NewExportersBuilder(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, factories.Exporters).Build()
+	exporters, err = BuildExporters(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, factories.Exporters)
 	assert.NotNil(t, exporters)
 	assert.NoError(t, err)
 
@@ -131,7 +131,7 @@ func TestExportersBuilder_BuildLogs(t *testing.T) {
 		},
 	}
 
-	exporters, err := NewExportersBuilder(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, factories.Exporters).Build()
+	exporters, err := BuildExporters(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, factories.Exporters)
 
 	assert.NoError(t, err)
 	require.NotNil(t, exporters)
@@ -156,7 +156,7 @@ func TestExportersBuilder_BuildLogs(t *testing.T) {
 	// This should result in creating an exporter that has none of consumption
 	// functions set.
 	delete(cfg.Service.Pipelines, "logs")
-	exporters, err = NewExportersBuilder(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, factories.Exporters).Build()
+	exporters, err = BuildExporters(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, factories.Exporters)
 	assert.NotNil(t, exporters)
 	assert.Nil(t, err)
 
@@ -260,7 +260,7 @@ func TestExportersBuilder_ErrorOnNilExporter(t *testing.T) {
 				},
 			}
 
-			exporters, err := NewExportersBuilder(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, fm).Build()
+			exporters, err := BuildExporters(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, fm)
 			assert.Error(t, err)
 			assert.Zero(t, len(exporters))
 		})

service/builder/extensions_builder.go

@@ -110,28 +110,24 @@ func (exts Extensions) ToMap() map[configmodels.NamedEntity]component.Extension
 	return result
 }
 
-// ExportersBuilder builds exporters from config.
-type ExtensionsBuilder struct {
+// exportersBuilder builds exporters from config.
+type extensionsBuilder struct {
 	logger    *zap.Logger
 	appInfo   component.ApplicationStartInfo
 	config    *configmodels.Config
 	factories map[configmodels.Type]component.ExtensionFactory
 }
 
-// NewExportersBuilder creates a new ExportersBuilder. Call BuildExporters() on the returned value.
-func NewExtensionsBuilder(
+// BuildExtensions builds Extensions from config.
+func BuildExtensions(
 	logger *zap.Logger,
 	appInfo component.ApplicationStartInfo,
 	config *configmodels.Config,
 	factories map[configmodels.Type]component.ExtensionFactory,
-) *ExtensionsBuilder {
-	return &ExtensionsBuilder{logger.With(zap.String(kindLogKey, kindLogExtension)), appInfo, config, factories}
-}
+) (Extensions, error) {
+	eb := &extensionsBuilder{logger.With(zap.String(kindLogKey, kindLogExtension)), appInfo, config, factories}
 
-// Build extensions from config.
-func (eb *ExtensionsBuilder) Build() (Extensions, error) {
 	extensions := make(Extensions)
-
 	for _, extName := range eb.config.Service.Extensions {
 		extCfg, exists := eb.config.Extensions[extName]
 		if !exists {
@@ -150,7 +146,7 @@ func (eb *ExtensionsBuilder) Build() (Extensions, error) {
 	return extensions, nil
 }
 
-func (eb *ExtensionsBuilder) buildExtension(logger *zap.Logger, appInfo component.ApplicationStartInfo, cfg configmodels.Extension) (*builtExtension, error) {
+func (eb *extensionsBuilder) buildExtension(logger *zap.Logger, appInfo component.ApplicationStartInfo, cfg configmodels.Extension) (*builtExtension, error) {
 	factory := eb.factories[cfg.Type()]
 	if factory == nil {
 		return nil, fmt.Errorf("extension factory for type %q is not configured", cfg.Type())

service/builder/pipelines_builder.go

@@ -78,31 +78,27 @@ func (bps BuiltPipelines) ShutdownProcessors(ctx context.Context) error {
 	return consumererror.CombineErrors(errs)
 }
 
-// PipelinesBuilder builds pipelines from config.
-type PipelinesBuilder struct {
+// pipelinesBuilder builds Pipelines from config.
+type pipelinesBuilder struct {
 	logger    *zap.Logger
 	appInfo   component.ApplicationStartInfo
 	config    *configmodels.Config
 	exporters Exporters
 	factories map[configmodels.Type]component.ProcessorFactory
 }
 
-// NewPipelinesBuilder creates a new PipelinesBuilder. Requires exporters to be already
-// built via ExportersBuilder. Call BuildProcessors() on the returned value.
-func NewPipelinesBuilder(
+// BuildPipelines builds pipeline processors from config. Requires exporters to be already
+// built via BuildExporters.
+func BuildPipelines(
 	logger *zap.Logger,
 	appInfo component.ApplicationStartInfo,
 	config *configmodels.Config,
 	exporters Exporters,
 	factories map[configmodels.Type]component.ProcessorFactory,
-) *PipelinesBuilder {
-	return &PipelinesBuilder{logger, appInfo, config, exporters, factories}
-}
+) (BuiltPipelines, error) {
+	pb := &pipelinesBuilder{logger, appInfo, config, exporters, factories}
 
-// BuildProcessors pipeline processors from config.
-func (pb *PipelinesBuilder) Build() (BuiltPipelines, error) {
 	pipelineProcessors := make(BuiltPipelines)
-
 	for _, pipeline := range pb.config.Service.Pipelines {
 		firstProcessor, err := pb.buildPipeline(context.Background(), pipeline)
 		if err != nil {
@@ -117,7 +113,7 @@ func (pb *PipelinesBuilder) Build() (BuiltPipelines, error) {
 // Builds a pipeline of processors. Returns the first processor in the pipeline.
 // The last processor in the pipeline will be plugged to fan out the data into exporters
 // that are configured for this pipeline.
-func (pb *PipelinesBuilder) buildPipeline(ctx context.Context, pipelineCfg *configmodels.Pipeline) (*builtPipeline, error) {
+func (pb *pipelinesBuilder) buildPipeline(ctx context.Context, pipelineCfg *configmodels.Pipeline) (*builtPipeline, error) {
 
 	// BuildProcessors the pipeline backwards.
 
@@ -219,7 +215,7 @@ func (pb *PipelinesBuilder) buildPipeline(ctx context.Context, pipelineCfg *conf
 }
 
 // Converts the list of exporter names to a list of corresponding builtExporters.
-func (pb *PipelinesBuilder) getBuiltExportersByNames(exporterNames []string) []*builtExporter {
+func (pb *pipelinesBuilder) getBuiltExportersByNames(exporterNames []string) []*builtExporter {
 	var result []*builtExporter
 	for _, name := range exporterNames {
 		exporter := pb.exporters[pb.config.Exporters[name]]
@@ -229,7 +225,7 @@ func (pb *PipelinesBuilder) getBuiltExportersByNames(exporterNames []string) []*
 	return result
 }
 
-func (pb *PipelinesBuilder) buildFanoutExportersTraceConsumer(exporterNames []string) consumer.TracesConsumer {
+func (pb *pipelinesBuilder) buildFanoutExportersTraceConsumer(exporterNames []string) consumer.TracesConsumer {
 	builtExporters := pb.getBuiltExportersByNames(exporterNames)
 
 	var exporters []consumer.TracesConsumer
@@ -241,7 +237,7 @@ func (pb *PipelinesBuilder) buildFanoutExportersTraceConsumer(exporterNames []st
 	return processor.NewTracesFanOutConnector(exporters)
 }
 
-func (pb *PipelinesBuilder) buildFanoutExportersMetricsConsumer(exporterNames []string) consumer.MetricsConsumer {
+func (pb *pipelinesBuilder) buildFanoutExportersMetricsConsumer(exporterNames []string) consumer.MetricsConsumer {
 	builtExporters := pb.getBuiltExportersByNames(exporterNames)
 
 	var exporters []consumer.MetricsConsumer
@@ -253,7 +249,7 @@ func (pb *PipelinesBuilder) buildFanoutExportersMetricsConsumer(exporterNames []
 	return processor.NewMetricsFanOutConnector(exporters)
 }
 
-func (pb *PipelinesBuilder) buildFanoutExportersLogConsumer(exporterNames []string) consumer.LogsConsumer {
+func (pb *pipelinesBuilder) buildFanoutExportersLogConsumer(exporterNames []string) consumer.LogsConsumer {
 	builtExporters := pb.getBuiltExportersByNames(exporterNames)
 
 	exporters := make([]consumer.LogsConsumer, len(builtExporters))

service/builder/pipelines_builder_test.go

@@ -133,15 +133,15 @@ func TestPipelinesBuilder_BuildVarious(t *testing.T) {
 			cfg := createExampleConfig(dataType)
 
 			// BuildProcessors the pipeline
-			allExporters, err := NewExportersBuilder(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, factories.Exporters).Build()
+			allExporters, err := BuildExporters(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, factories.Exporters)
 			if test.shouldFail {
 				assert.Error(t, err)
 				return
 			}
 
 			require.NoError(t, err)
 			require.EqualValues(t, 1, len(allExporters))
-			pipelineProcessors, err := NewPipelinesBuilder(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, allExporters, factories.Processors).Build()
+			pipelineProcessors, err := BuildPipelines(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, allExporters, factories.Processors)
 
 			assert.NoError(t, err)
 			require.NotNil(t, pipelineProcessors)
@@ -205,9 +205,9 @@ func testPipeline(t *testing.T, pipelineName string, exporterNames []string) {
 	require.Nil(t, err)
 
 	// BuildProcessors the pipeline
-	allExporters, err := NewExportersBuilder(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, factories.Exporters).Build()
+	allExporters, err := BuildExporters(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, factories.Exporters)
 	assert.NoError(t, err)
-	pipelineProcessors, err := NewPipelinesBuilder(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, allExporters, factories.Processors).Build()
+	pipelineProcessors, err := BuildPipelines(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, allExporters, factories.Processors)
 
 	assert.NoError(t, err)
 	require.NotNil(t, pipelineProcessors)
@@ -266,7 +266,7 @@ func TestProcessorsBuilder_ErrorOnUnsupportedProcessor(t *testing.T) {
 	cfg, err := configtest.LoadConfigFile(t, "testdata/bad_processor_factory.yaml", factories)
 	require.Nil(t, err)
 
-	allExporters, err := NewExportersBuilder(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, factories.Exporters).Build()
+	allExporters, err := BuildExporters(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, factories.Exporters)
 	assert.NoError(t, err)
 
 	// First test only trace receivers by removing the metrics pipeline.
@@ -276,7 +276,7 @@ func TestProcessorsBuilder_ErrorOnUnsupportedProcessor(t *testing.T) {
 	delete(cfg.Service.Pipelines, "logs")
 	require.Equal(t, 1, len(cfg.Service.Pipelines))
 
-	pipelineProcessors, err := NewPipelinesBuilder(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, allExporters, factories.Processors).Build()
+	pipelineProcessors, err := BuildPipelines(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, allExporters, factories.Processors)
 	assert.Error(t, err)
 	assert.Zero(t, len(pipelineProcessors))
 
@@ -285,7 +285,7 @@ func TestProcessorsBuilder_ErrorOnUnsupportedProcessor(t *testing.T) {
 	cfg.Service.Pipelines["metrics"] = metricsPipeline
 	require.Equal(t, 1, len(cfg.Service.Pipelines))
 
-	pipelineProcessors, err = NewPipelinesBuilder(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, allExporters, factories.Processors).Build()
+	pipelineProcessors, err = BuildPipelines(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, allExporters, factories.Processors)
 	assert.Error(t, err)
 	assert.Zero(t, len(pipelineProcessors))
 
@@ -294,7 +294,7 @@ func TestProcessorsBuilder_ErrorOnUnsupportedProcessor(t *testing.T) {
 	cfg.Service.Pipelines["logs"] = logsPipeline
 	require.Equal(t, 1, len(cfg.Service.Pipelines))
 
-	pipelineProcessors, err = NewPipelinesBuilder(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, allExporters, factories.Processors).Build()
+	pipelineProcessors, err = BuildPipelines(zap.NewNop(), component.DefaultApplicationStartInfo(), cfg, allExporters, factories.Processors)
 	assert.Error(t, err)
 	assert.Zero(t, len(pipelineProcessors))
 }

service/builder/receivers_builder.go

@@ -77,31 +77,26 @@ func (rcvs Receivers) StartAll(ctx context.Context, host component.Host) error {
 	return nil
 }
 
-// ReceiversBuilder builds receivers from config.
-type ReceiversBuilder struct {
+// receiversBuilder builds receivers from config.
+type receiversBuilder struct {
 	logger         *zap.Logger
 	appInfo        component.ApplicationStartInfo
 	config         *configmodels.Config
 	builtPipelines BuiltPipelines
 	factories      map[configmodels.Type]component.ReceiverFactory
 }
 
-// NewReceiversBuilder creates a new ReceiversBuilder. Call BuildProcessors() on the returned value.
-func NewReceiversBuilder(
+// BuildReceivers builds Receivers from config.
+func BuildReceivers(
 	logger *zap.Logger,
 	appInfo component.ApplicationStartInfo,
 	config *configmodels.Config,
 	builtPipelines BuiltPipelines,
 	factories map[configmodels.Type]component.ReceiverFactory,
-) *ReceiversBuilder {
-	return &ReceiversBuilder{logger.With(zap.String(kindLogKey, kindLogsReceiver)), appInfo, config, builtPipelines, factories}
-}
+) (Receivers, error) {
+	rb := &receiversBuilder{logger.With(zap.String(kindLogKey, kindLogsReceiver)), appInfo, config, builtPipelines, factories}
 
-// BuildProcessors receivers from config.
-func (rb *ReceiversBuilder) Build() (Receivers, error) {
 	receivers := make(Receivers)
-
-	// BuildProcessors receivers based on configuration.
 	for _, cfg := range rb.config.Receivers {
 		logger := rb.logger.With(zap.String(typeLogKey, string(cfg.Type())), zap.String(nameLogKey, cfg.Name()))
 		rcv, err := rb.buildReceiver(context.Background(), logger, rb.appInfo, cfg)
@@ -130,7 +125,7 @@ func hasReceiver(pipeline *configmodels.Pipeline, receiverName string) bool {
 
 type attachedPipelines map[configmodels.DataType][]*builtPipeline
 
-func (rb *ReceiversBuilder) findPipelinesToAttach(config configmodels.Receiver) (attachedPipelines, error) {
+func (rb *receiversBuilder) findPipelinesToAttach(config configmodels.Receiver) (attachedPipelines, error) {
 	// A receiver may be attached to multiple pipelines. Pipelines may consume different
 	// data types. We need to compile the list of pipelines of each type that must be
 	// attached to this receiver according to configuration.
@@ -163,7 +158,7 @@ func (rb *ReceiversBuilder) findPipelinesToAttach(config configmodels.Receiver)
 	return pipelinesToAttach, nil
 }
 
-func (rb *ReceiversBuilder) attachReceiverToPipelines(
+func (rb *receiversBuilder) attachReceiverToPipelines(
 	ctx context.Context,
 	logger *zap.Logger,
 	appInfo component.ApplicationStartInfo,
@@ -237,7 +232,7 @@ func (rb *ReceiversBuilder) attachReceiverToPipelines(
 	return nil
 }
 
-func (rb *ReceiversBuilder) buildReceiver(ctx context.Context, logger *zap.Logger, appInfo component.ApplicationStartInfo, config configmodels.Receiver) (*builtReceiver, error) {
+func (rb *receiversBuilder) buildReceiver(ctx context.Context, logger *zap.Logger, appInfo component.ApplicationStartInfo, config configmodels.Receiver) (*builtReceiver, error) {
 
 	// First find pipelines that must be attached to this receiver.
 	pipelinesToAttach, err := rb.findPipelinesToAttach(config)