fix: expression resolution on span name and tags (#225)

src/main/java/com/avioconsulting/mule/opentelemetry/internal/interceptor/ProcessorTracingInterceptor.java

@@ -4,7 +4,6 @@
 import com.avioconsulting.mule.opentelemetry.api.store.TransactionStore;
 import com.avioconsulting.mule.opentelemetry.api.traces.TraceComponent;
 import com.avioconsulting.mule.opentelemetry.internal.processor.MuleNotificationProcessor;
-import com.avioconsulting.mule.opentelemetry.internal.util.ComponentsUtil;
 import org.mule.runtime.api.component.Component;
 import org.mule.runtime.api.component.location.ComponentLocation;
 import org.mule.runtime.api.component.location.ConfigurationComponentLocator;
@@ -24,6 +23,7 @@
 import static com.avioconsulting.mule.opentelemetry.api.store.TransactionStore.*;
 import static com.avioconsulting.mule.opentelemetry.internal.util.ComponentsUtil.*;
 import static com.avioconsulting.mule.opentelemetry.internal.util.OpenTelemetryUtil.getEventTransactionId;
+import static com.avioconsulting.mule.opentelemetry.internal.util.OpenTelemetryUtil.resolveExpressions;
 
 /**
  * Interceptor to set tracing context information in flow a variable
@@ -102,6 +102,8 @@ public void before(
         }
         LOGGER.trace("Creating Span in the interceptor for {} at {}",
             location.getComponentIdentifier().getIdentifier(), location.getLocation());
+        resolveExpressions(traceComponent,
+            muleNotificationProcessor.getOpenTelemetryConnection().getExpressionManager(), event);
         muleNotificationProcessor.getOpenTelemetryConnection().addProcessorSpan(traceComponent,
             getLocationParent(location.getLocation()));
         final String transactionId = getEventTransactionId(event);

src/main/java/com/avioconsulting/mule/opentelemetry/internal/processor/MuleNotificationProcessor.java

@@ -41,6 +41,7 @@
 import static com.avioconsulting.mule.opentelemetry.internal.util.ComponentsUtil.getTraceComponent;
 import static com.avioconsulting.mule.opentelemetry.internal.util.ComponentsUtil.isFlowRef;
 import static com.avioconsulting.mule.opentelemetry.internal.util.ComponentsUtil.resolveFlowName;
+import static com.avioconsulting.mule.opentelemetry.internal.util.OpenTelemetryUtil.resolveExpressions;
 
 /**
  * Notification Processor bean. This is injected through registry-bootstrap into
@@ -180,6 +181,8 @@ private void processComponentStartSpan(EnrichedServerNotification notification)
             .withStartTime(Instant.ofEpochMilli(notification.getTimestamp()))
             .withEventContextId(notification.getEvent().getContext().getId())
             .withComponentLocation(notification.getComponent().getLocation());
+        resolveExpressions(traceComponent, openTelemetryConnection.getExpressionManager(),
+            notification.getEvent());
         openTelemetryConnection.addProcessorSpan(traceComponent,
             ComponentsUtil.getLocationParent(notification.getComponent().getLocation().getLocation()));
         processFlowRef(traceComponent, notification.getEvent());

src/main/java/com/avioconsulting/mule/opentelemetry/internal/util/OpenTelemetryUtil.java

@@ -1,14 +1,19 @@
 package com.avioconsulting.mule.opentelemetry.internal.util;
 
+import com.avioconsulting.mule.opentelemetry.api.traces.TraceComponent;
 import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.common.AttributesBuilder;
 import org.mule.runtime.api.event.Event;
 import org.mule.runtime.api.event.EventContext;
+import org.mule.runtime.api.metadata.TypedValue;
+import org.mule.runtime.core.api.el.ExpressionManager;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.stream.Collectors;
 
 public class OpenTelemetryUtil {
 
@@ -88,4 +93,39 @@ public static void addAttribute(String property, AttributesBuilder builder,
     }
   }
 
+  /**
+   * Resolves any expressions in the TraceComponent's spanName and tags using the
+   * provided ExpressionManager
+   * based on the given Event.
+   *
+   * @param traceComponent
+   *            the TraceComponent containing spanName and tags to resolve
+   * @param expressionManager
+   *            the ExpressionManager used to evaluate expressions
+   * @param event
+   *            the Event used for context in expression evaluation
+   */
+  public static void resolveExpressions(TraceComponent traceComponent, ExpressionManager expressionManager,
+      Event event) {
+    try {
+      if (expressionManager
+          .isExpression(traceComponent.getSpanName())) {
+        TypedValue<String> evaluatedSpanName = (TypedValue<String>) expressionManager
+            .evaluate(traceComponent.getSpanName(), event.asBindingContext());
+        if (evaluatedSpanName.getValue() != null) {
+          traceComponent.withSpanName(evaluatedSpanName.getValue());
+        }
+      }
+      List<Map.Entry<String, String>> expressionTags = traceComponent.getTags().entrySet().stream()
+          .filter(e -> expressionManager.isExpression(e.getValue())).collect(Collectors.toList());
+      for (Map.Entry<String, String> expressionTag : expressionTags) {
+        TypedValue<String> evaluate = (TypedValue<String>) expressionManager.evaluate(expressionTag.getValue(),
+            event.asBindingContext());
+        if (evaluate.getValue() != null) {
+          traceComponent.getTags().replace(expressionTag.getKey(), evaluate.getValue());
+        }
+      }
+    } catch (Exception ignored) {
+    }
+  }
 }

src/test/java/com/avioconsulting/mule/opentelemetry/MuleOpenTelemetryHttpTest.java

@@ -321,4 +321,22 @@ public void testRequestSpanWithBasePath() throws Exception {
               .containsExactly("/api/remote/invalid", "CLIENT");
         }));
   }
+
+  @Test
+  public void testHTTPSpanNames_withExpression() throws Exception {
+    Throwable throwable = catchThrowable(() -> flowRunner("flow-call-remote-with-expression")
+        .withVariable("resourcePath", "/expression/secrets")
+        .run());
+    await().untilAsserted(() -> assertThat(DelegatedLoggingSpanTestExporter.spanQueue)
+        .hasSize(2)
+        .element(0).as("Span for http:request flow")
+        .extracting("spanName", "spanKind")
+        .containsOnly("/expression/secrets", "CLIENT"));
+    DelegatedLoggingSpanTestExporter.Span client = getSpan("CLIENT", "/expression/secrets");
+    assertThat(client).isNotNull()
+        .extracting("attributes", as(InstanceOfAssertFactories.map(String.class, Object.class)))
+        .containsEntry("http.route", "/expression/secrets");
+
+  }
+
 }

src/test/java/com/avioconsulting/mule/opentelemetry/internal/interceptor/ProcessorTracingInterceptorTest.java

@@ -19,6 +19,7 @@
 import org.mule.runtime.api.interception.InterceptionAction;
 import org.mule.runtime.api.interception.InterceptionEvent;
 import org.mule.runtime.api.metadata.TypedValue;
+import org.mule.runtime.core.api.el.ExpressionManager;
 
 import java.util.Collections;
 import java.util.Map;
@@ -239,8 +240,11 @@ public void verifyVariableResetOnTraceComponentNotFound() {
   public void verifyVariableResetOnTraceComponentFound() {
     OpenTelemetryConnection connection = mock(OpenTelemetryConnection.class);
     TransactionStore transactionStore = mock(TransactionStore.class);
+    ExpressionManager expressionManager = mock(ExpressionManager.class);
+    when(expressionManager.isExpression(anyString())).thenReturn(false);
     when(connection.getTransactionStore()).thenReturn(transactionStore);
     when(transactionStore.transactionIdFor(any())).thenReturn("random-id");
+    when(connection.getExpressionManager()).thenReturn(expressionManager);
 
     Map<String, String> traceparentMap = Collections.singletonMap("traceparent", "some-value");
     ComponentLocation location = mock(ComponentLocation.class);

src/test/resources/mule-opentelemetry-http.xml

@@ -146,4 +146,7 @@ http://www.mulesoft.org/schema/mule/opentelemetry http://www.mulesoft.org/schema
 	<sub-flow name="sub-flow-call-remote-target"  >
 		<http:request method="GET" doc:name="Request" config-ref="SELF_HTTP_Request_configuration" path="/test/remote/target"/>
 	</sub-flow>
+	<flow name="flow-call-remote-with-expression"  >
+		<http:request method="GET" doc:name="Request" config-ref="SELF_HTTP_Request_configuration" path="#[vars.resourcePath]"/>
+	</flow>
 </mule>