Expose public method to create OC Exporter (open-telemetry#323)

Refactored the code to make NewMetricsExporter/NewTraceExporter public.

exporter/opencensusexporter/factory.go

@@ -28,7 +28,6 @@ import (
  compressiongrpc "github.com/open-telemetry/opentelemetry-service/compression/grpc"
  "github.com/open-telemetry/opentelemetry-service/config/configmodels"
  "github.com/open-telemetry/opentelemetry-service/exporter"
- "github.com/open-telemetry/opentelemetry-service/exporter/exporterhelper"
 )
 
 const (
@@ -63,40 +62,7 @@ func (f *Factory) CreateTraceExporter(logger *zap.Logger, config configmodels.Ex
  if err != nil {
  return nil, err
  }
- oce, err := f.createOCAgentExporter(logger, ocac, opts)
- if err != nil {
- return nil, err
- }
- oexp, err := exporterhelper.NewTraceExporter(
- config,
- oce.PushTraceData,
- exporterhelper.WithTracing(true),
- exporterhelper.WithMetrics(true),
- exporterhelper.WithShutdown(oce.Shutdown))
- if err != nil {
- return nil, err
- }
-
- return oexp, nil
-}
-
-// createOCAgentExporter takes ocagent exporter options and create an OC exporter
-func (f *Factory) createOCAgentExporter(logger *zap.Logger, ocac *Config, opts []ocagent.ExporterOption) (*ocagentExporter, error) {
- numWorkers := defaultNumWorkers
- if ocac.NumWorkers > 0 {
- numWorkers = ocac.NumWorkers
- }
-
- exportersChan := make(chan *ocagent.Exporter, numWorkers)
- for exporterIndex := 0; exporterIndex < numWorkers; exporterIndex++ {
- exporter, serr := ocagent.NewExporter(opts...)
- if serr != nil {
- return nil, fmt.Errorf("cannot configure OpenCensus exporter: %v", serr)
- }
- exportersChan <- exporter
- }
- oce := &ocagentExporter{exporters: exportersChan}
- return oce, nil
+ return NewTraceExporter(logger, config, opts...)
 }
 
 // OCAgentOptions takes the oc exporter Config and generates ocagent Options
@@ -159,26 +125,10 @@ func (f *Factory) OCAgentOptions(logger *zap.Logger, ocac *Config) ([]ocagent.Ex
 
 // CreateMetricsExporter creates a metrics exporter based on this config.
 func (f *Factory) CreateMetricsExporter(logger *zap.Logger, config configmodels.Exporter) (exporter.MetricsExporter, error) {
- ocac := config.(*Config)
- opts, err := f.OCAgentOptions(logger, ocac)
- if err != nil {
- return nil, err
- }
- oce, err := f.createOCAgentExporter(logger, ocac, opts)
+ oCfg := config.(*Config)
+ opts, err := f.OCAgentOptions(logger, oCfg)
  if err != nil {
  return nil, err
  }
-
- oexp, err := exporterhelper.NewMetricsExporter(
- config,
- oce.PushMetricsData,
- exporterhelper.WithTracing(true),
- exporterhelper.WithMetrics(true),
- exporterhelper.WithShutdown(oce.Shutdown))
-
- if err != nil {
- return nil, err
- }
-
- return oexp, nil
+ return NewMetricsExporter(logger, config, opts...)
 }

exporter/opencensusexporter/opencensus.go

@@ -23,8 +23,11 @@ import (
  "contrib.go.opencensus.io/exporter/ocagent"
  agentmetricspb "github.com/census-instrumentation/opencensus-proto/gen-go/agent/metrics/v1"
  agenttracepb "github.com/census-instrumentation/opencensus-proto/gen-go/agent/trace/v1"
+ "go.uber.org/zap"
 
+ "github.com/open-telemetry/opentelemetry-service/config/configmodels"
  "github.com/open-telemetry/opentelemetry-service/consumer/consumerdata"
+ "github.com/open-telemetry/opentelemetry-service/exporter"
  "github.com/open-telemetry/opentelemetry-service/exporter/exporterhelper"
  "github.com/open-telemetry/opentelemetry-service/oterr"
 )
@@ -37,7 +40,7 @@ type KeepaliveConfig struct {
  PermitWithoutStream bool `mapstructure:"permit-without-stream,omitempty"`
 }
 
-type ocagentExporter struct {
+type ocAgentExporter struct {
  exporters chan *ocagent.Exporter
 }
 
@@ -67,7 +70,65 @@ const (
  errAlreadyStopped
 )
 
-func (oce *ocagentExporter) Shutdown() error {
+// NewTraceExporter creates an Open Census trace exporter.
+func NewTraceExporter(logger *zap.Logger, config configmodels.Exporter, opts ...ocagent.ExporterOption) (exporter.TraceExporter, error) {
+ oce, err := createOCAgentExporter(logger, config, opts...)
+ if err != nil {
+ return nil, err
+ }
+ oexp, err := exporterhelper.NewTraceExporter(
+ config,
+ oce.PushTraceData,
+ exporterhelper.WithTracing(true),
+ exporterhelper.WithMetrics(true),
+ exporterhelper.WithShutdown(oce.Shutdown))
+ if err != nil {
+ return nil, err
+ }
+
+ return oexp, nil
+}
+
+// createOCAgentExporter takes ocagent exporter options and create an OC exporter
+func createOCAgentExporter(logger *zap.Logger, config configmodels.Exporter, opts ...ocagent.ExporterOption) (*ocAgentExporter, error) {
+ oCfg := config.(*Config)
+ numWorkers := defaultNumWorkers
+ if oCfg.NumWorkers > 0 {
+ numWorkers = oCfg.NumWorkers
+ }
+
+ exportersChan := make(chan *ocagent.Exporter, numWorkers)
+ for exporterIndex := 0; exporterIndex < numWorkers; exporterIndex++ {
+ exporter, serr := ocagent.NewExporter(opts...)
+ if serr != nil {
+ return nil, fmt.Errorf("cannot configure OpenCensus exporter: %v", serr)
+ }
+ exportersChan <- exporter
+ }
+ oce := &ocAgentExporter{exporters: exportersChan}
+ return oce, nil
+}
+
+// NewMetricsExporter creates an Open Census metrics exporter.
+func NewMetricsExporter(logger *zap.Logger, config configmodels.Exporter, opts ...ocagent.ExporterOption) (exporter.MetricsExporter, error) {
+ oce, err := createOCAgentExporter(logger, config, opts...)
+ if err != nil {
+ return nil, err
+ }
+ oexp, err := exporterhelper.NewMetricsExporter(
+ config,
+ oce.PushMetricsData,
+ exporterhelper.WithTracing(true),
+ exporterhelper.WithMetrics(true),
+ exporterhelper.WithShutdown(oce.Shutdown))
+ if err != nil {
+ return nil, err
+ }
+
+ return oexp, nil
+}
+
+func (oce *ocAgentExporter) Shutdown() error {
  wg := &sync.WaitGroup{}
  var errors []error
  var errorsMu sync.Mutex
@@ -96,7 +157,7 @@ func (oce *ocagentExporter) Shutdown() error {
  return oterr.CombineErrors(errors)
 }
 
-func (oce *ocagentExporter) PushTraceData(ctx context.Context, td consumerdata.TraceData) (int, error) {
+func (oce *ocAgentExporter) PushTraceData(ctx context.Context, td consumerdata.TraceData) (int, error) {
  // Get first available exporter.
  exporter, ok := <-oce.exporters
  if !ok {
@@ -121,7 +182,7 @@ func (oce *ocagentExporter) PushTraceData(ctx context.Context, td consumerdata.T
  return 0, nil
 }
 
-func (oce *ocagentExporter) PushMetricsData(ctx context.Context, md consumerdata.MetricsData) (int, error) {
+func (oce *ocAgentExporter) PushMetricsData(ctx context.Context, md consumerdata.MetricsData) (int, error) {
  // Get first available exporter.
  exporter, ok := <-oce.exporters
  if !ok {