From 936e18534639baf1e0403e2e0746159e6d622452 Mon Sep 17 00:00:00 2001
From: user1 <user1@localhost>
Date: Mon, 2 Nov 2020 15:19:31 +1100
Subject: [PATCH] Added tests and header propagation to start transactions

---
 mule4-agent/pom.xml                           |  2 +-
 .../apm/mule4/agent/span/SpanUtils.java       | 11 ++++++++++
 .../mule4/agent/tracing/HttpTracingUtils.java | 20 +++++++++++++++++++
 .../mule4/agent/DistributedTracingTest.java   | 13 ++++++++++++
 4 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/mule4-agent/pom.xml b/mule4-agent/pom.xml
index a4a13de..2b4e3a8 100644
--- a/mule4-agent/pom.xml
+++ b/mule4-agent/pom.xml
@@ -4,7 +4,7 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>co.elastic.apm</groupId>
 	<artifactId>mule4-agent</artifactId>
-	<version>0.2.0</version>
+	<version>0.3.0</version>
 	<name>Elastic Mule 4 APM agent</name>
 	<description>Elastic Mule 4 APM agent</description>
 	<packaging>jar</packaging>
diff --git a/mule4-agent/src/main/java/co/elastic/apm/mule4/agent/span/SpanUtils.java b/mule4-agent/src/main/java/co/elastic/apm/mule4/agent/span/SpanUtils.java
index b8c4486..e6ae2cc 100644
--- a/mule4-agent/src/main/java/co/elastic/apm/mule4/agent/span/SpanUtils.java
+++ b/mule4-agent/src/main/java/co/elastic/apm/mule4/agent/span/SpanUtils.java
@@ -11,6 +11,7 @@
 import co.elastic.apm.api.ElasticApm;
 import co.elastic.apm.api.Span;
 import co.elastic.apm.api.Transaction;
+import co.elastic.apm.mule4.agent.tracing.HttpTracingUtils;
 import co.elastic.apm.mule4.agent.transaction.TransactionStore;
 
 /*
@@ -38,6 +39,8 @@ public static void startSpan(TransactionStore transactionStore, MessageProcessor
 
 		Span span = transaction.startSpan(getSpanType(notification), getSubType(notification), getAction(notification));
 
+		checkAndPropagateParentTraceId(span, notification);
+
 		setSpanDetails(span, notification);
 
 		String spanId = getSpanId(notification);
@@ -45,6 +48,14 @@ public static void startSpan(TransactionStore transactionStore, MessageProcessor
 		transactionStore.addSpan(transactionId, spanId, span);
 	}
 
+	private static void checkAndPropagateParentTraceId(Span span, MessageProcessorNotification notification) {
+
+		// Propagate trace.id through HTTP
+		if (HttpTracingUtils.isHttpRequester(notification))
+			HttpTracingUtils.propagateTraceIdHeader(span, notification);
+
+	}
+
 	public static String getSpanId(MessageProcessorNotification notification) {
 		return notification.getInfo().getComponent().getLocation().getLocation();
 	}
diff --git a/mule4-agent/src/main/java/co/elastic/apm/mule4/agent/tracing/HttpTracingUtils.java b/mule4-agent/src/main/java/co/elastic/apm/mule4/agent/tracing/HttpTracingUtils.java
index 2a45865..4e93759 100644
--- a/mule4-agent/src/main/java/co/elastic/apm/mule4/agent/tracing/HttpTracingUtils.java
+++ b/mule4-agent/src/main/java/co/elastic/apm/mule4/agent/tracing/HttpTracingUtils.java
@@ -1,12 +1,18 @@
 package co.elastic.apm.mule4.agent.tracing;
 
 import org.mule.extension.http.api.HttpRequestAttributes;
+import org.mule.runtime.api.component.ComponentIdentifier;
 import org.mule.runtime.api.metadata.TypedValue;
+import org.mule.runtime.api.notification.MessageProcessorNotification;
 import org.mule.runtime.api.notification.PipelineMessageNotification;
 import org.mule.runtime.api.util.MultiMap;
 
+import co.elastic.apm.api.Span;
+
 public class HttpTracingUtils {
 
+	private static final String HTTP_REQUEST_NAMESPACE = "http://www.mulesoft.org/schema/mule/http";
+	private static final String HTTP_REQUEST_NAME = "request";
 	public static final String ELASTIC_APM_TRACEPARENT = "elastic-apm-traceparent";
 
 	public static boolean isHttpEvent(PipelineMessageNotification notification) {
@@ -36,4 +42,18 @@ private static TypedValue<Object> extractAttributes(PipelineMessageNotification
 		return notification.getEvent().getMessage().getAttributes();
 	}
 
+	public static boolean isHttpRequester(MessageProcessorNotification notification) {
+		
+		ComponentIdentifier identifier = notification.getInfo().getComponent().getIdentifier();
+		String name = identifier.getName();
+		String namespace = identifier.getNamespaceUri();
+		
+		return HTTP_REQUEST_NAME.equals(name) && HTTP_REQUEST_NAMESPACE.equals(namespace);
+	}
+
+	public static void propagateTraceIdHeader(Span span, MessageProcessorNotification notification) {
+		// TODO Auto-generated method stub
+		
+	}
+
 }
diff --git a/mule4-agent/src/test/java/co/elastic/apm/mule4/agent/DistributedTracingTest.java b/mule4-agent/src/test/java/co/elastic/apm/mule4/agent/DistributedTracingTest.java
index 09138e0..11d5d07 100644
--- a/mule4-agent/src/test/java/co/elastic/apm/mule4/agent/DistributedTracingTest.java
+++ b/mule4-agent/src/test/java/co/elastic/apm/mule4/agent/DistributedTracingTest.java
@@ -60,6 +60,19 @@ public void testNoTraceIdPropagation() throws Exception {
 
 	}
 
+	@Test
+	public void testTraceIdPropagationThroughHttp() throws Exception {
+
+		HttpGet getRequest = new HttpGet("http://localhost:8998");
+		getRequest.addHeader(HttpTracingUtils.ELASTIC_APM_TRACEPARENT, TRACE_PARENT1);
+
+		HttpClient httpClient = HttpClientBuilder.create().build();
+
+		HttpResponse response = httpClient.execute(getRequest);
+
+
+	}
+	
 	@Override
 	protected String getConfigFile() {
 		return "DistributedTracingTest.xml";