Remove spans with ec2 metadata ip address from metrics (#1015)

*Issue #, if available:*
ADOT SDK resource detectors by default have enabled a few AWS resource
detector which will call EC2 metadata API endpoints. These activities
have been captured by auto-instrumentation and generated AppSignals
metrics.

These calls should be present in traces, but not in metrics. 

*Description of changes:*
Suppress AwsSpanMetricsProcessor from generating metrics when the
RemoteService points to `169.254.169.254`

*Testing*
Deployed two EC2 instance with Java sample application and ADOT Java 
- `sample-application-2025-02-06-test`: ADOT Java with changes in this
PR
- `sample-application-2025-02-06`: Public latest ADOT Java

*Traces:*
Present from both EC2 instance

![image](https://github.com/user-attachments/assets/9c10a81d-0336-473f-81f3-9d4e61069401)

![image](https://github.com/user-attachments/assets/8be02cc9-dddb-4461-834e-98ad65d5a23f)

*Metrics*:
Present only for `sample-application-2025-02-06`:

![image](https://github.com/user-attachments/assets/97d29884-7133-47b5-aa0e-c5ac7a09cc3e)

*Logs*:
Present only for `sample-application-2025-02-06`:




By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 license.

Author: harrryr

awsagentprovider/src/main/java/software/amazon/opentelemetry/javaagent/providers/AwsSpanMetricsProcessor.java

@@ -17,6 +17,7 @@
 
 import static io.opentelemetry.semconv.SemanticAttributes.HTTP_RESPONSE_STATUS_CODE;
 import static io.opentelemetry.semconv.SemanticAttributes.HTTP_STATUS_CODE;
+import static software.amazon.opentelemetry.javaagent.providers.AwsAttributeKeys.AWS_REMOTE_SERVICE;
 import static software.amazon.opentelemetry.javaagent.providers.AwsSpanProcessingUtil.isKeyPresent;
 
 import io.opentelemetry.api.common.Attributes;
@@ -61,6 +62,10 @@ public final class AwsSpanMetricsProcessor implements SpanProcessor {
   private static final int FAULT_CODE_LOWER_BOUND = 500;
   private static final int FAULT_CODE_UPPER_BOUND = 599;
 
+  // EC2 Metadata API IP Address
+  // https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instancedata-data-retrieval.html#instancedata-inside-access
+  private final String EC2_METADATA_API_IP = "169.254.169.254";
+
   // Metric instruments
   private final LongHistogram errorHistogram;
   private final LongHistogram faultHistogram;
@@ -172,9 +177,18 @@ private void recordLatency(ReadableSpan span, Attributes attributes) {
 
   private void recordMetrics(ReadableSpan span, SpanData spanData, Attributes attributes) {
     // Only record metrics if non-empty attributes are returned.
-    if (!attributes.isEmpty()) {
+    if (!attributes.isEmpty() && !isEc2MetadataSpan((attributes))) {
       recordErrorOrFault(spanData, attributes);
       recordLatency(span, attributes);
     }
   }
+
+  private boolean isEc2MetadataSpan(Attributes attributes) {
+    if (attributes.get(AWS_REMOTE_SERVICE) != null
+        && attributes.get(AWS_REMOTE_SERVICE).equals(EC2_METADATA_API_IP)) {
+      return true;
+    }
+
+    return false;
+  }
 }

awsagentprovider/src/test/java/software/amazon/opentelemetry/javaagent/providers/AwsSpanMetricsProcessorTest.java

@@ -25,6 +25,7 @@
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoInteractions;
 import static org.mockito.Mockito.when;
+import static software.amazon.opentelemetry.javaagent.providers.AwsAttributeKeys.AWS_REMOTE_SERVICE;
 import static software.amazon.opentelemetry.javaagent.providers.MetricAttributeGenerator.DEPENDENCY_METRIC;
 import static software.amazon.opentelemetry.javaagent.providers.MetricAttributeGenerator.SERVICE_METRIC;
 
@@ -378,6 +379,21 @@ public void testOnEndMetricsGenerationWithStatusDataOk() {
     validateMetricsGeneratedForStatusDataOk(600L, ExpectedStatusMetric.NEITHER);
   }
 
+  @Test
+  public void testOnEndMetricsGenerationFromEc2MetadataApi() {
+    Attributes spanAttributes = Attributes.of(AWS_REMOTE_SERVICE, "169.254.169.254");
+    ReadableSpan readableSpanMock =
+        buildReadableSpanMock(
+            spanAttributes, SpanKind.CLIENT, SpanContext.getInvalid(), StatusData.unset());
+    Map<String, Attributes> metricAttributesMap = buildEc2MetadataApiMetricAttributes();
+    configureMocksForOnEnd(readableSpanMock, metricAttributesMap);
+
+    awsSpanMetricsProcessor.onEnd(readableSpanMock);
+    verifyNoInteractions(errorHistogramMock);
+    verifyNoInteractions(faultHistogramMock);
+    verifyNoInteractions(latencyHistogramMock);
+  }
+
   private static Attributes buildSpanAttributes(boolean containsAttribute) {
     if (containsAttribute) {
       return Attributes.of(AttributeKey.stringKey("original key"), "original value");
@@ -404,6 +420,14 @@ private static Map<String, Attributes> buildMetricAttributes(
     return attributesMap;
   }
 
+  private static Map<String, Attributes> buildEc2MetadataApiMetricAttributes() {
+    Map<String, Attributes> attributesMap = new HashMap<>();
+    Attributes attributes =
+        Attributes.of(AttributeKey.stringKey(AWS_REMOTE_SERVICE.toString()), "169.254.169.254");
+    attributesMap.put(MetricAttributeGenerator.DEPENDENCY_METRIC, attributes);
+    return attributesMap;
+  }
+
   private static ReadableSpan buildReadableSpanMock(Attributes spanAttributes) {
     return buildReadableSpanMock(spanAttributes, SpanKind.SERVER, null, StatusData.unset());
   }