Baggage management in OpenTelemetry.Instrumentation.AWSLambda

[arkoste]

I'm using OpenTelemetry.Instrumentation.AWSLambda (1.15.1 on .NETCore 8.0).

I'm wrapping the lambdaHandler with AWSLambdaWrapper.TraceAsync.

SQSMessage attributes received by the handler contain traceparent and baggage.

AWSLambdaWrapper.TraceAsync calls internal static (ActivityContext ParentContext, IEnumerable? Links) ExtractParentContext(TInput input) but even if internally the function extracts the baggage (due to default propagator) , as for the signature, the method do not return it to the caller or set it as Baggage.Current.

Is this a design choice or whatever?

Thanks

[martincostello]

as for the signature, the method do not return it to the caller or set it as Baggage.Current.

Could you clarify exactly what you're asking?

[arkoste]

ExtractParentContext returns (ActivityContext ParentContext, IEnumerable? Links).

From its code:

...

case SQSEvent.SQSMessage sqsMessage:
        parentContext = AWSMessagingUtils.ExtractParentContext(sqsMessage);
        break;

...
return (parentContext.ActivityContext, links);

is not parentContext.Baggage missing?

Is there another way to obtain the Baggage from the lambdaHandler (because i see it empty)?

[martincostello]

The code here should extract the baggage using the Propagators.DefaultTextMapPropagator property, which as long as the SDK is being used should automatically configure propagation of trace context and baggage: code.

opentelemetry-dotnet-contrib/src/OpenTelemetry.Instrumentation.AWSLambda/Implementation/AWSMessagingUtils.cs

Line 56 in 6b37ec2

var parentContext = Propagators.DefaultTextMapPropagator.Extract(default, sqsMessage.MessageAttributes, SqsMessageAttributeGetter);

If your application doesn't use the SDK in the OpenTelemetry package, then you will need to manually configure DefaultTextMapPropagator or manually add the baggage:

var propagator = new CompositeTextMapPropagator(
[
    new TraceContextPropagator(),
    new BaggagePropagator(),
]);

Sdk.SetDefaultTextMapPropagator(propagator);

[arkoste]

The code here should extract the baggage using the Propagators.DefaultTextMapPropagator property, which as long as the SDK is being used should automatically configure propagation of trace context and baggage: code.

Yes, i use the DefaultPropagator (composite one) and i expect it to extrat also the baggage (and i think it does).

The problem (?!?) is that this code:

opentelemetry-dotnet-contrib/src/OpenTelemetry.Instrumentation.AWSLambda/Implementation/AWSMessagingUtils.cs

Line 56 in 6b37ec2

var parentContext = Propagators.DefaultTextMapPropagator.Extract(default, sqsMessage.MessageAttributes, SqsMessageAttributeGetter);

is called inside this method:

opentelemetry-dotnet-contrib/src/OpenTelemetry.Instrumentation.AWSLambda/Implementation/AWSLambdaUtils.cs

Line 80 in 6b37ec2

internal static (ActivityContext ParentContext, IEnumerable<ActivityLink>? Links) ExtractParentContext<TInput>(TInput input)

at line 99. It returns a propagationContext (i suppose with both: ActivityContext and Baggage) but at the end

opentelemetry-dotnet-contrib/src/OpenTelemetry.Instrumentation.AWSLambda/Implementation/AWSLambdaUtils.cs

Line 111 in 6b37ec2

return (parentContext.ActivityContext, links);

WSLambdaUtils.ExtractParentContext returns only the ActivityContext one to AWSLamdaWrapper

opentelemetry-dotnet-contrib/src/OpenTelemetry.Instrumentation.AWSLambda/AWSLambdaWrapper.cs

Line 161 in 6b37ec2

(parentContext, links) = AWSLambdaUtils.ExtractParentContext(input);

Am i wrong?

If your application doesn't use the SDK in the OpenTelemetry package, then you will need to manually configure DefaultTextMapPropagator or manually add the baggage:

var propagator = new CompositeTextMapPropagator(
[
    new TraceContextPropagator(),
    new BaggagePropagator(),
]);

Sdk.SetDefaultTextMapPropagator(propagator);

[martincostello]

If you think you've found a bug, please create a minimal reproducible example as a self-contained GitHub repository so we can debug it and take a look.