added README for sigv4 exporter and added a more graceful fall through for catching missing dependencies

Author: liustve

aws-opentelemetry-distro/src/amazon/opentelemetry/distro/otlp-aws-span-exporter/README.md

@@ -0,0 +1,28 @@
+# ADOT X-Ray OTLP Trace Export Configuration
+
+This guide explains how to automatically configure ADOT environment variables for exporting traces to [AWS X-Ray OTLP endpoint](https://docs.aws.amazon.com/xray/latest/devguide/xray-opentelemetry.html)
+
+## Pre-requisites:
+1. Transaction Search must be enabled in order to send spans to the Xray OTLP endpoint. See [this doc](https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/CloudWatch-Transaction-Search-getting-started.html) on how to enable Transaction Search.
+
+2. Ensure the AWS credentials in your application environment has the `xray:PutTraceSegments` action allowed.
+
+## Environment Variables
+
+Set the following environment variables to **PROPERLY** configure trace export with SigV4 authentication:
+
+```shell
+# Set X-Ray endpoint (replace AWS_REGION with your region)
+OTEL_EXPORTER_OTLP_TRACES_ENDPOINT=https://xray.<AWS_REGION>.amazonaws.com/v1/traces
+
+# Configure OTLP export protocol
+OTEL_EXPORTER_OTLP_PROTOCOL=http/protobuf
+
+OTEL_METRICS_EXPORTER=none
+OTEL_LOGS_EXPORTER=none
+OTEL_PYTHON_DISTRO=aws_distro
+OTEL_PYTHON_CONFIGURATOR=aws_configurator
+OTEL_RESOURCE_ATTRIBUTES="service.name=<YOUR_SERVICE_NAME>"
+
+# Disable application signals (they will be generated in CloudWatch backend)
+OTEL_AWS_APPLICATION_SIGNALS_ENABLED=false

aws-opentelemetry-distro/src/amazon/opentelemetry/distro/otlp_aws_span_exporter.py renamed to aws-opentelemetry-distro/src/amazon/opentelemetry/distro/otlp-aws-span-exporter/otlp_aws_span_exporter.py

@@ -35,6 +35,7 @@ def __init__(
     ):
 
         self._aws_region = None
+        self._has_dependencies = False
 
         # Requires botocore to be installed to sign the headers. However,
         # some users might not need to use this exporter. In order not conflict
@@ -52,6 +53,7 @@ def __init__(
             # The only usecase for this class would be for ADOT Python Auto Instrumentation and that already validates
             # the endpoint to be an XRay OTLP endpoint.
             self._aws_region = endpoint.split(".")[1]
+            self._has_dependencies = True
 
         else:
             _logger.error(
@@ -74,23 +76,24 @@ def __init__(
     # the same except if the endpoint is an XRay OTLP endpoint, we will sign the request
     # with SigV4 in headers before sending it to the endpoint. Otherwise, we will skip signing.
     def _export(self, serialized_data: bytes):
-        request = self.boto_aws_request.AWSRequest(
-            method="POST",
-            url=self._endpoint,
-            data=serialized_data,
-            headers={"Content-Type": "application/x-protobuf"},
-        )
+        if(self._has_dependencies):
+            request = self.boto_aws_request.AWSRequest(
+                method="POST",
+                url=self._endpoint,
+                data=serialized_data,
+                headers={"Content-Type": "application/x-protobuf"},
+            )
 
-        credentials = self.boto_session.get_credentials()
+            credentials = self.boto_session.get_credentials()
 
-        if credentials is not None:
-            signer = self.boto_auth.SigV4Auth(credentials, AWS_SERVICE, self._aws_region)
+            if credentials is not None:
+                signer = self.boto_auth.SigV4Auth(credentials, AWS_SERVICE, self._aws_region)
 
-            try:
-                signer.add_auth(request)
-                self._session.headers.update(dict(request.headers))
+                try:
+                    signer.add_auth(request)
+                    self._session.headers.update(dict(request.headers))
 
-            except Exception as signing_error:  # pylint: disable=broad-except
-                _logger.error("Failed to sign request: %s", signing_error)
+                except Exception as signing_error:  # pylint: disable=broad-except
+                    _logger.error("Failed to sign request: %s", signing_error)
 
         return super()._export(serialized_data)