Multilang daemon does not support AWS_CSM (Client side monitoring)

[kyleip]

AWS_CSM is a feature that enables sending certain metrics via UDP connection to the CSM agent. This feature should be enabled by setting an environment variable like AWS_CSM_ENABLED=true, and is supported by the aws-java-sdk: https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/monitoring/DefaultCsmConfigurationProviderChain.html .

Here is some sample java code that shows that this is supposed to work with the aws-java-sdk:

public class App 
{
    public static void main( String[] args )
    {
        AmazonS3 s3 = AmazonS3ClientBuilder.standard()
            .withRegion("us-west-2")
            .build();
        System.out.println( "Hello World!" );
        List<Bucket> buckets = s3.listBuckets();
        System.out.println("Your {S3} buckets are:");
        for (Bucket b : buckets) {
            System.out.println("* " + b.getName());
        }
    }
}

And if you set AWS_CSM_ENABLED=true and run the program, while you have while true; do nc -ulv 31000 -w0 ; done running in another window, you will see that this works for the aws-java-sdk.

But i haven't gotten this to work with the Multilang Daemon. I am running the kclrb sample producer and processor on my laptop with the AWS_CSM_ENABLED var set, but the java-sdk is not emitting any metrics. Can we add support for AWS_CSM to the multilang daemon?