Add tracing spans in CRI image service and pull.go

Signed-off-by: Swagat Bora <sbora@amazon.com>

Add spans around image unpack operations
Use image.ref to denote image name and image.id for the image config digest
Add top-level spand and record errors in the CRI instrumentation service

tracing/plugin/otlp.go

@@ -137,6 +137,7 @@ func newTracer(ic *plugin.InitContext) (io.Closer, error) {
 	config := ic.Config.(*TraceConfig)
 
 	res, err := resource.New(ctx,
+		resource.WithHost(),
 		resource.WithAttributes(
 			// Service name used to displace traces in backends
 			semconv.ServiceNameKey.String(config.ServiceName),
@@ -146,8 +147,10 @@ func newTracer(ic *plugin.InitContext) (io.Closer, error) {
 		return nil, fmt.Errorf("failed to create resource: %w", err)
 	}
 
+	sampler := sdktrace.ParentBased(sdktrace.TraceIDRatioBased(config.TraceSamplingRatio))
+
 	opts := []sdktrace.TracerProviderOption{
-		sdktrace.WithSampler(sdktrace.TraceIDRatioBased(config.TraceSamplingRatio)),
+		sdktrace.WithSampler(sampler),
 		sdktrace.WithResource(res),
 	}
 
@@ -175,7 +178,8 @@ func newTracer(ic *plugin.InitContext) (io.Closer, error) {
 	provider := sdktrace.NewTracerProvider(opts...)
 
 	otel.SetTracerProvider(provider)
-	otel.SetTextMapPropagator(propagation.TraceContext{})
+
+	otel.SetTextMapPropagator(propagators())
 
 	return &closer{close: func() error {
 		for _, p := range procs {
@@ -186,3 +190,8 @@ func newTracer(ic *plugin.InitContext) (io.Closer, error) {
 		return nil
 	}}, nil
 }
+
+// Returns a composite TestMap propagator
+func propagators() propagation.TextMapPropagator {
+	return propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{})
+}

tracing/tracing.go

@@ -20,6 +20,7 @@ import (
 	"context"
 
 	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/codes"
 	"go.opentelemetry.io/otel/trace"
 )
 
@@ -35,3 +36,19 @@ func StartSpan(ctx context.Context, opName string, opts ...trace.SpanStartOption
 func StopSpan(span trace.Span) {
 	span.End()
 }
+
+// CurrentSpan returns current span from context or noopSpan if no span exists.
+func CurrentSpan(ctx context.Context) trace.Span {
+	return trace.SpanFromContext(ctx)
+}
+
+// SetSpanStatus sets the status of the current span.
+// If an error is encountered, it records the error and sets span status to Error.
+func SetSpanStatus(span trace.Span, err error) {
+	if err != nil {
+		span.RecordError(err)
+		span.SetStatus(codes.Error, err.Error())
+	} else {
+		span.SetStatus(codes.Ok, "")
+	}
+}