Add OTLP UDP exporter

[srprash]

Description

Implementing a UDP exporter for OTLP spans and metrics. Few notes:

• If AppSignals is enabled in Lambda, the OTel spans and Application Signals metrics are always exported via this UdpExporter. Currently it can't be configured to use any other exporter.
• Custom OTel metrics can still be exported (if enabled and requires using ADOT Collector layer) via user-specified exporter.
• OTel spans and Appsignals metrics are first protobuf encoded, then base64 encoded, then prefixed with T1 or M1 respectively, and finally appended to the '{"format":"json","version":1}\n' string before being exported to the address provided in the AWS_XRAY_DAEMON_ADDRESS or default 127.0.0.1:2000.

Testing

• Test script test_lambda.py to generate 2 nested spans:

  if __name__ == "__main__":
  tracer = trace.get_tracer("test-tracer")
  with tracer.start_as_current_span("parent"):
      # Attach a new child and update the current span
      with tracer.start_as_current_span("child"):
          # sleep for 1s
          sleep(1)
      # Close child span, set parent as current
  # Close parent span, set default span as current

• Command to run the script with auto-instrumentation:

  OTEL_TRACES_EXPORTER=otlp \
  OTEL_METRICS_EXPORTER=none \
  OTEL_LOGS_EXPORTER=none \
  OTEL_AWS_APPLICATION_SIGNALS_ENABLED=true \
  OTEL_PYTHON_DISTRO=aws_distro \
  OTEL_PYTHON_CONFIGURATOR=aws_configurator \
  OTEL_EXPORTER_OTLP_PROTOCOL=http/protobuf \ # this config will be ignored since appsignals is enabled in lambda
  OTEL_TRACES_SAMPLER=always_on \
  OTEL_RESOURCE_ATTRIBUTES="service.name=lambda_test" \
  AWS_LAMBDA_FUNCTION_NAME="lambda_func_name" \
  opentelemetry-instrument python test_lambda.py

• Printed spans in JSON format
  Raw spans:

{
    "name": "child",
    "context": {
        "trace_id": "0x66bbf01064511ad55e9fe435a1326167",
        "span_id": "0x0915f345ead6d194",
        "trace_state": "[]"
    },
    "kind": "SpanKind.INTERNAL",
    "parent_id": "0xbd128e94b0caa171",
    "start_time": "2024-08-13T23:45:20.930139Z",
    "end_time": "2024-08-13T23:45:21.935234Z",
    "status": {
        "status_code": "UNSET"
    },
    "attributes": {
        "aws.local.operation": "InternalOperation"
    },
    "events": [],
    "links": [],
    "resource": {
        "attributes": {
            "telemetry.sdk.language": "python",
            "telemetry.sdk.name": "opentelemetry",
            "telemetry.sdk.version": "1.25.0",
            "service.name": "lambda_test",
            "telemetry.auto.version": "0.3.0.dev0-aws"
        },
        "schema_url": ""
    }
}
{
    "name": "parent",
    "context": {
        "trace_id": "0x66bbf01064511ad55e9fe435a1326167",
        "span_id": "0xbd128e94b0caa171",
        "trace_state": "[]"
    },
    "kind": "SpanKind.INTERNAL",
    "parent_id": null,
    "start_time": "2024-08-13T23:45:20.930107Z",
    "end_time": "2024-08-13T23:45:21.935353Z",
    "status": {
        "status_code": "UNSET"
    },
    "attributes": {
        "aws.local.operation": "InternalOperation",
        "aws.local.service": "lambda_test",
        "aws.span.kind": "LOCAL_ROOT"
    },
    "events": [],
    "links": [],
    "resource": {
        "attributes": {
            "telemetry.sdk.language": "python",
            "telemetry.sdk.name": "opentelemetry",
            "telemetry.sdk.version": "1.25.0",
            "service.name": "lambda_test",
            "telemetry.auto.version": "0.3.0.dev0-aws"
        },
        "schema_url": ""
    }
}

Encoded trace data from SDK:

"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"

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[wangzlei]

Could you help me understand how to configure span_exporter to be UDP exporter?

[wangzlei]

Look good to me!