Go lambda instrumentation enhancements (#1413)

* added failure scenario when getting container fails

* fix test case failure

* add changelog

* fix ecs resource detector bug

* fix struct name as per golint suggestion

* minor changes

* added NewResourceDetector func and interface assertions

* fix golint failure

* minor changes to address review comments

* lambda go instrumentation enhancements

* minor changes to address review comments

* update go.mod

* Revert "update go.mod"

This reverts commit 2696b35.

* remove depending on SDK package

* renaming the public API for xrayconfig package

* fix README review suggestions

* remove logger and minor changes

* Update instrumentation/github.com/aws/aws-lambda-go/otellambda/xrayconfig/xrayconfig_test.go

Co-authored-by: Anthony Mirabella <a9@aneurysm9.com>
Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>

instrumentation/github.com/aws/aws-lambda-go/otellambda/xrayconfig/README.md

@@ -34,7 +34,7 @@ func HandleRequest(ctx context.Context, name MyEvent) (string, error) {
 }
 
 func main() {
-	lambda.Start(otellambda.WrapHandlerFunction(HandleRequest))
+	lambda.Start(otellambda.InstrumentHandler(HandleRequest))
 }
 ```
 
@@ -44,19 +44,19 @@ Now configure the instrumentation with the provided options to export traces to
 // Add import
 import "go.opentelemetry.io/contrib/instrumentation/github.com/aws/aws-lambda-go/otellambda/xrayconfig"
 
-// add options to WrapHandlerFunction call
+// add options to InstrumentHandler call
 func main() {
-	lambda.Start(otellambda.WrapHandlerFunction(HandleRequest, xrayconfig.AllRecommendedOptions()...))
+	lambda.Start(otellambda.InstrumentHandler(HandleRequest, xrayconfig.WithRecommendedOptions()...))
 }
 ```
 ## Recommended AWS Lambda Instrumentation Options
 
 | Instrumentation Option | Recommended Value | Exported As |
 | --- | --- | --- |
-| `WithTracerProvider` | An `sdktrace.TracerProvider` configured to export in batches to an OTel Collector running locally in Lambda | Not individually exported. Can only be used via `AllRecommendedOptions()`
-| `WithFlusher` | An `otellambda.Flusher` which yields before calling ForceFlush on the configured `sdktrace.TracerProvider`. Yielding mitigates data delays caused by asynchronous nature of batching TracerProvider when in Lambda | Not individually exported. Can only be used via `AllRecommendedOptions()`
-| `WithEventToCarrier` | Function which reads X-Ray TraceID from Lambda environment and inserts it into a `propagtation.TextMapCarrier` | Individually exported as `EventToCarrier()`, also included in `AllRecommendedOptions()`
-| `WithPropagator` | An `xray.propagator` | Individually exported as `EventToCarrier()`, also included in `AllRecommendedOptions()`
+| `WithTracerProvider` | An `sdktrace.TracerProvider` configured to export in batches to an OTel Collector running locally in Lambda | Not individually exported. Can only be used via `WithRecommendedOptions()`
+| `WithFlusher` | An `otellambda.Flusher` which yields before calling ForceFlush on the configured `sdktrace.TracerProvider`. Yielding mitigates data delays caused by asynchronous nature of batching TracerProvider when in Lambda | Not individually exported. Can only be used via `WithRecommendedOptions()`
+| `WithEventToCarrier` | Function which reads X-Ray TraceID from Lambda environment and inserts it into a `propagtation.TextMapCarrier` | Individually exported as `WithEventToCarrier()`, also included in `WithRecommendedOptions()`
+| `WithPropagator` | An `xray.propagator` | Individually exported as `WithPropagator()`, also included in `WithRecommendedOptions()`
 
 
 ## Useful links

instrumentation/github.com/aws/aws-lambda-go/otellambda/xrayconfig/xrayconfig.go

@@ -16,9 +16,7 @@ package xrayconfig
 
 import (
 	"context"
-	"log"
 	"os"
-	"runtime"
 
 	lambdadetector "go.opentelemetry.io/contrib/detectors/aws/lambda"
 	"go.opentelemetry.io/contrib/instrumentation/github.com/aws/aws-lambda-go/otellambda"
@@ -28,79 +26,48 @@ import (
 	sdktrace "go.opentelemetry.io/otel/sdk/trace"
 )
 
-var errorLogger = log.New(log.Writer(), "OTel Lambda XRay Configuration Error: ", 0)
-
 func xrayEventToCarrier([]byte) propagation.TextMapCarrier {
 	xrayTraceID := os.Getenv("_X_AMZN_TRACE_ID")
 	return propagation.HeaderCarrier{"X-Amzn-Trace-Id": []string{xrayTraceID}}
 }
 
-type asyncSafeFlusher struct {
-	tp *sdktrace.TracerProvider
-}
-
-func (f asyncSafeFlusher) ForceFlush(ctx context.Context) error {
-	// yield processor to attempt to ensure all spans have
-	// been consumed and are ready to be flushed
-	// - see https://github.com/open-telemetry/opentelemetry-go/issues/2080
-	// to be removed upon resolution of above issue
-	runtime.Gosched()
-
-	return f.tp.ForceFlush(ctx)
-}
-
-// tracerProviderAndFlusher returns a list of otellambda.Option(s) to
-// enable using a TracerProvider configured for AWS XRay via a collector
-// and an otellambda.Flusher to flush this TracerProvider.
-// tracerProviderAndFlusher is not exported because it should not be used
-// without the provided EventToCarrier function and XRay Propagator
-func tracerProviderAndFlusher() ([]otellambda.Option, error) {
-	ctx := context.Background()
-
-	// Do not need transport security in Lambda because collector
-	// runs locally in Lambda execution environment
+// NewTracerProvider returns a TracerProvider configured with an exporter,
+// ID generator, and lambda resource detector to send trace data to AWS X-Ray
+// via a Collector instance listening on localhost
+func NewTracerProvider(ctx context.Context) (*sdktrace.TracerProvider, error) {
 	exp, err := otlptracegrpc.New(ctx, otlptracegrpc.WithInsecure())
 	if err != nil {
-		return []otellambda.Option{}, err
+		return nil, err
 	}
 
 	detector := lambdadetector.NewResourceDetector()
-	res, err := detector.Detect(ctx)
+	resource, err := detector.Detect(ctx)
 	if err != nil {
-		return []otellambda.Option{}, err
+		return nil, err
 	}
 
-	tp := sdktrace.NewTracerProvider(
+	return sdktrace.NewTracerProvider(
 		sdktrace.WithBatcher(exp),
 		sdktrace.WithIDGenerator(xray.NewIDGenerator()),
-		sdktrace.WithResource(res),
-	)
-
-	return []otellambda.Option{otellambda.WithTracerProvider(tp), otellambda.WithFlusher(asyncSafeFlusher{tp: tp})}, nil
+		sdktrace.WithResource(resource),
+	), nil
 }
 
-// EventToCarrier returns an otellambda.Option to enable
+// WithEventToCarrier returns an otellambda.Option to enable
 // an otellambda.EventToCarrier function which reads the XRay trace
 // information from the environment and returns this information in
 // a propagation.HeaderCarrier
-func EventToCarrier() otellambda.Option {
+func WithEventToCarrier() otellambda.Option {
 	return otellambda.WithEventToCarrier(xrayEventToCarrier)
 }
 
-// Propagator returns an otellambda.Option to enable the xray.Propagator
-func Propagator() otellambda.Option {
-
+// WithPropagator returns an otellambda.Option to enable the xray.Propagator
+func WithPropagator() otellambda.Option {
 	return otellambda.WithPropagator(xray.Propagator{})
 }
 
-// AllRecommendedOptions returns a list of all otellambda.Option(s)
+// WithRecommendedOptions returns a list of all otellambda.Option(s)
 // recommended for the otellambda package when using AWS XRay
-func AllRecommendedOptions() []otellambda.Option {
-	options, err := tracerProviderAndFlusher()
-	if err != nil {
-		// should we fail to create the TracerProvider, do not alter otellambda's default configuration
-		errorLogger.Println("failed to create recommended configuration: ", err)
-		return []otellambda.Option{}
-	}
-	return append(options, []otellambda.Option{EventToCarrier(), Propagator()}...)
+func WithRecommendedOptions(tp *sdktrace.TracerProvider) []otellambda.Option {
+	return []otellambda.Option{WithEventToCarrier(), WithPropagator(), otellambda.WithTracerProvider(tp), otellambda.WithFlusher(tp)}
 }

instrumentation/github.com/aws/aws-lambda-go/otellambda/xrayconfig/xrayconfig_test.go

@@ -154,6 +154,10 @@ func assertSpanEqualsIgnoreTimeAndSpanID(t *testing.T, expected *v1trace.Resourc
 func TestWrapEndToEnd(t *testing.T) {
 	setEnvVars()
 
+	ctx := context.Background()
+	tp, err := NewTracerProvider(ctx)
+	assert.NoError(t, err)
+
 	customerHandler := func() (string, error) {
 		return "hello world", nil
 	}
@@ -163,7 +167,7 @@ func TestWrapEndToEnd(t *testing.T) {
 	}()
 	<-time.After(5 * time.Millisecond)
 
-	wrapped := otellambda.InstrumentHandler(customerHandler, AllRecommendedOptions()...)
+	wrapped := otellambda.InstrumentHandler(customerHandler, WithRecommendedOptions(tp)...)
 	wrappedCallable := reflect.ValueOf(wrapped)
 	resp := wrappedCallable.Call([]reflect.Value{reflect.ValueOf(mockContext)})
 	assert.Len(t, resp, 2)