aws-lambda: Cannot use AdotInstrumentation for dotnet lambdas

[Dreamescaper]

Describe the bug

Accodring to the Getting Started page, you don't need to set ExecWrapper for dotnet lambdas. However, ExecWrapper is required with CDK.

Regression Issue

• [ ] Select this option if this issue appears to be a regression.

Expected Behavior

AdotInstrumentation should allow to omit ExecWrapper property.

Current Behavior

ExecWrapper property is mandatory.

Reproduction Steps

new Function(this, "func-id", new FunctionProps
{
    Handler = "My::Handler::Method",
    Code = Code.FromAsset("publish/MyCode.zip"),
    Runtime = Runtime.DOTNET_8,
    AdotInstrumentation = new AdotInstrumentationConfig
    {
        LayerVersion = AdotLayerVersion.FromGenericLayerVersion(AdotLambdaLayerGenericVersion.LATEST)
    }
});

// SII001   The property ExecWrapper is required and cannot be null.

Language

.NET

[ashishdhingra]

Findings:

• execWrapper is marked as required (not optional) per AdotInstrumentationConfig definition.
• execWrapper accepts one of the values defined as part of AdotLambdaExecWrapper enum.
• If you check the commit history, execWrapper is the required field since last 2 years.
• The link AWS Distro for OpenTelemetry Lambda Support For .NET demonstrates adding manual instrumentation using .NET as an example.
• If you refer other links (except .NET and Go), e.g. AWS Distro for OpenTelemetry Lambda Support For JavaScript, it talks about setting AWS_LAMBDA_EXEC_WRAPPER environment variable.
• The value set for execWrapper sets the environment variable AWS_LAMBDA_EXEC_WRAPPER here.
• Per AWS Lambda > Wrapper scripts, environment variable AWS_LAMBDA_EXEC_WRAPPER could be used to set file system path of an executable binary or script, which allows to customize the runtime startup behavior of your Lambda function. A wrapper script enables you to set configuration parameters that cannot be set through language-specific environment variables.
• Unsure if automatic tracing could be enabled for .NET and if execWrapper should be required for .NET.

@Dreamescaper Could you please share what happens if you set execWrapper to AdotLambdaExecWrapper.REGULAR_HANDLER.

[ashishdhingra]

Internal tracking ticket: P150043839

[ashishdhingra]

Update on internal tracking ticket: execWrapper is not mandatory.