Problems with 'aws-xray-sdk-core'

[micro-jumbo]

Hi,

I have this small lambda function:

import {ListBucketsCommand, S3Client} from "@aws-sdk/client-s3";

export const handle = async () => {
    const s3Client = new S3Client();
    const rest = await s3Client.send(new ListBucketsCommand());
    rest.Buckets?.forEach(bucket => {
        console.log(bucket.Name);
    });
    console.log('Hello world');
}

which works great.

But when I want to capture calls to S3 with X-Ray traces using the aws-xray-sdk-core library:

import {captureAWSv3Client} from 'aws-xray-sdk-core';
...
    const s3Client = captureAWSv3Client(new S3Client());
....

it starts failing with error:

2024-10-14T20:11:17.555Z	n/a	FATAL	ReferenceError: Error resolving module '/var/task/assert' from '/var/task/index.mjs'
  at <anonymous> (/var/task/index.mjs:1:4249)
      at <anonymous> (/var/task/index.mjs:1:458)
      at <anonymous> (/var/task/index.mjs:6:16634)
      at <anonymous> (/var/task/index.mjs:1:458)
      at <anonymous> (/var/task/index.mjs:6:89512)
      at <anonymous> (/var/task/index.mjs:1:458)
      at <anonymous> (/var/task/index.mjs:6:91308)
      at <anonymous> (/var/task/index.mjs:1:458)
      at <anonymous> (/var/task/index.mjs:6:91325)
INIT_REPORT Init Duration: 62.39 ms	Phase: init	Status: error	Error Type: Runtime.ExitError
2024-10-14T20:11:18.415Z	n/a	FATAL	ReferenceError: Error resolving module '/var/task/assert' from '/var/task/index.mjs'
  at <anonymous> (/var/task/index.mjs:1:4249)
      at <anonymous> (/var/task/index.mjs:1:458)
      at <anonymous> (/var/task/index.mjs:6:16634)
      at <anonymous> (/var/task/index.mjs:1:458)
      at <anonymous> (/var/task/index.mjs:6:89512)
      at <anonymous> (/var/task/index.mjs:1:458)
      at <anonymous> (/var/task/index.mjs:6:91308)
      at <anonymous> (/var/task/index.mjs:1:458)
      at <anonymous> (/var/task/index.mjs:6:91325)
INIT_REPORT Init Duration: 934.90 ms	Phase: invoke	Status: error	Error Type: Runtime.ExitError
START RequestId: 40310a38-3d40-4569-a631-e8e103a5105c Version: $LATEST
RequestId: 40310a38-3d40-4569-a631-e8e103a5105c Error: Runtime exited with error: exit status 1
Runtime.ExitError
END RequestId: 40310a38-3d40-4569-a631-e8e103a5105c
REPORT RequestId: 40310a38-3d40-4569-a631-e8e103a5105c	Duration: 975.40 ms	Billed Duration: 976 ms	Memory Size: 128 MB	Max Memory Used: 19 MB	
XRAY TraceId: 1-670d7ae5-67eb6e644cea659b394342d3	SegmentId: 44f97b661735d32b	Sampled: true	

Lambda function is created using cdk-lambda-llrt cdk construct:

import {LlrtBinaryType, LlrtFunction} from "cdk-lambda-llrt";

class MyLambda extends LlrtFunction {
    constructor(scope: Construct, id: string) {
        super(scope, id, {
            entry: path.resolve(__dirname, './handlers/my-lambda.ts'),
            handler: 'handle',
            llrtBinaryType: LlrtBinaryType.FULL_SDK,
            tracing: Tracing.ACTIVE,
            architecture: cdk.aws_lambda.Architecture.ARM_64,
        });
        this.addToRolePolicy(new cdk.aws_iam.PolicyStatement({
            actions: ['s3:*'],
            resources: ['*'],
        }));
    }
}

Any idea what the problem might be and how to solve it?

[nabetti1720]

The error message is a bit odd, but it means that the Node.js assert module is not supported by LLRT at this time. The modules that are supported at this time are listed below.
https://github.com/awslabs/llrt?tab=readme-ov-file#compatibility-matrix

[micro-jumbo]

I just checked the call chain and aws-xray-sdk-core calls cls-hooked, which uses assert.

What would be the best path to follow if I wanted to provide a shim for the assert (or any other) module to llrt?

[richarddavison]

Hi, thanks for your report. It's a bit hard to tell, but for one the assert module is not supported. I also suspect that aws-xray-sdk-core might use a lot of node APIs not yet implemented. I'll take a closer look once I get the opportunity