Set up UDP Release Workflow (#333)

**Description of changes:**
Setting up the validation steps for the GitHub workflow we intend to use
to manually trigger a UDP exporter release to PyPI.

At a high-level, this validation step will:
- Build the UDP exporter.
- Set up and run an instance of X-Ray daemon.
- Run a validation app to send traces to X-Ray daemon via UDP exporter.
- Validation step to verify that daemon received the traces.

TODO:
- Add a publish to PyPI step to release workflow.

**Test plan:**
Triggered workflow in feature branch:


https://github.com/aws-observability/aws-otel-python-instrumentation/actions/runs/13663595075


By submitting this pull request, I confirm that you can use, modify,
copy, and redistribute this contribution, under the terms of your
choice.

Author: yiyuan-he

.github/workflows/release-udp-exporter.yml

@@ -0,0 +1,77 @@
+name: Release ADOT OTLP UDP Exporter
+
+on:
+  workflow_dispatch:
+    inputs:
+      version:
+        description: 'Version number for deployment e.g. 0.1.0'
+        required: true
+        type: string
+
+jobs:
+  build-test-publish:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.10'
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install hatch pytest flask
+
+      - name: Build package
+        working-directory: exporters/aws-otel-otlp-udp-exporter
+        run: hatch build
+
+      - name: Download and run X-Ray Daemon
+        run: |
+          mkdir xray-daemon
+          cd xray-daemon
+          wget https://s3.us-west-2.amazonaws.com/aws-xray-assets.us-west-2/xray-daemon/aws-xray-daemon-linux-3.x.zip
+          unzip aws-xray-daemon-linux-3.x.zip
+          ./xray -o -n us-west-2 -f ./daemon-logs.log --log-level debug &
+
+      - name: Install UDP Exporter
+        run: |
+          pip install ./exporters/aws-otel-otlp-udp-exporter/dist/*.whl
+
+      - name: Ensure Unit Tests are passing
+        run: |
+          pytest exporters/aws-otel-otlp-udp-exporter/tests/
+
+      - name: Run Sample App in Background
+        working-directory: sample-applications/integ-test-app
+        run: |
+          # Start validation app
+          python udp_exporter_validation_app.py &
+          # Wait for validation app to initialize
+          sleep 5
+
+      - name: Call Sample App Endpoint
+        run: |
+          echo "traceId=$(curl localhost:8080/test)" >> $GITHUB_OUTPUT
+
+      - name: Verify X-Ray daemon received traces
+        run: |
+          sleep 10
+          echo "X-Ray daemon logs:"
+          cat xray-daemon/daemon-logs.log
+
+          # Check if the daemon received and processed some data
+          if grep -q "sending.*batch" xray-daemon/daemon-logs.log; then
+            echo "✅ X-Ray daemon processed trace data (AWS upload errors are expected)"
+            exit 0
+          elif grep -q "processor:.*segment" xray-daemon/daemon-logs.log; then
+            echo "✅ X-Ray daemon processed segment data (AWS upload errors are expected)"
+            exit 0
+          else
+            echo "❌ No evidence of traces being received by X-Ray daemon"
+            exit 1
+          fi
+
+      # TODO: Steps to publish to PyPI

exporters/aws-otel-otlp-udp-exporter/src/amazon/opentelemetry/exporters/otlp/udp/exporter.py

@@ -23,10 +23,6 @@
 
 class UdpExporter:
     def __init__(self, endpoint: Optional[str] = None):
-        if endpoint is None and "AWS_LAMBDA_FUNCTION_NAME" in os.environ:
-            # If in an AWS Lambda Environment, `AWS_XRAY_DAEMON_ADDRESS` will be defined
-            endpoint = os.environ.get("AWS_XRAY_DAEMON_ADDRESS", DEFAULT_ENDPOINT)
-
         self._endpoint = endpoint or DEFAULT_ENDPOINT
         self._host, self._port = self._parse_endpoint(self._endpoint)
         self._socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
@@ -61,6 +57,10 @@ def _parse_endpoint(self, endpoint: str) -> Tuple[str, int]:
 
 class OTLPUdpSpanExporter(SpanExporter):
     def __init__(self, endpoint: Optional[str] = None, sampled: bool = True):
+        if endpoint is None and "AWS_LAMBDA_FUNCTION_NAME" in os.environ:
+            # If in an AWS Lambda Environment, `AWS_XRAY_DAEMON_ADDRESS` will be defined
+            endpoint = os.environ.get("AWS_XRAY_DAEMON_ADDRESS", DEFAULT_ENDPOINT)
+
         self._udp_exporter = UdpExporter(endpoint=endpoint)
         self._sampled = sampled
 

sample-applications/integ-test-app/udp_exporter_validation_app.py

@@ -0,0 +1,48 @@
+from flask import Flask
+
+from amazon.opentelemetry.exporters.otlp.udp import OTLPUdpSpanExporter
+from opentelemetry import trace
+from opentelemetry.sdk.trace import TracerProvider
+from opentelemetry.sdk.trace.export import BatchSpanProcessor
+
+app = Flask(__name__)
+
+# Set up tracer provider
+tracer_provider = TracerProvider()
+trace.set_tracer_provider(tracer_provider)
+
+# Set up UDP exporter with batch processor
+exporter = OTLPUdpSpanExporter(endpoint="127.0.0.1:2000")
+span_processor = BatchSpanProcessor(exporter)
+tracer_provider.add_span_processor(span_processor)
+
+# Get tracer
+tracer = trace.get_tracer(__name__)
+
+
+@app.route("/test", methods=["GET"])
+def create_trace():
+    # Create a span for testing with various attributes
+    tracer = trace.get_tracer(__name__)
+    with tracer.start_as_current_span("test_parent_span") as parent:
+        parent.set_attribute("service.name", "validation-app")
+        parent.set_attribute("test.attribute", "test_value")
+        parent.add_event("test-event", {"event.data": "some data"})
+
+        # Get the trace ID
+        trace_id = format(parent.get_span_context().trace_id, "032x")
+
+        # Add a child span
+        with tracer.start_as_current_span("test_child_span") as child:
+            child.set_attribute("child.attribute", "child_value")
+            print("Created spans with attributes and events")
+
+    # Force flush to ensure spans are exported immediately
+    success = tracer_provider.force_flush()
+    print(f"Force flush {'succeeded' if success else 'failed'}")
+
+    return trace_id
+
+
+if __name__ == "__main__":
+    app.run(port=8080)