fixing possible NPE in Apache Camel instrumentation (open-telemetry#2250)

Author: kuba-wu

instrumentation/apache-camel-2.20/javaagent-unittests/apache-camel-2.20-javaagent-unittests.gradle

@@ -4,7 +4,9 @@ dependencies {
   testImplementation project(':instrumentation:apache-camel-2.20:javaagent')
   testImplementation group: 'org.apache.camel', name: 'camel-core', version: '2.20.1'
   testImplementation group: 'org.apache.camel', name: 'camel-aws', version: '2.20.1'
+  testImplementation group: 'org.apache.camel', name: 'camel-http', version: '2.20.1'
 
+  testImplementation deps.opentelemetryTraceProps
   testImplementation deps.opentelemetryExtAws
   testImplementation group: 'org.assertj', name: 'assertj-core', version: '3.18.1'
 }

instrumentation/apache-camel-2.20/javaagent-unittests/src/test/groovy/io/opentelemetry/javaagent/instrumentation/apachecamel/CamelPropagationUtilTest.java

@@ -7,21 +7,86 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+import io.opentelemetry.api.GlobalOpenTelemetry;
+import io.opentelemetry.api.OpenTelemetry;
 import io.opentelemetry.api.trace.Span;
 import io.opentelemetry.api.trace.SpanContext;
 import io.opentelemetry.context.Context;
+import io.opentelemetry.context.propagation.ContextPropagators;
+import io.opentelemetry.extension.trace.propagation.JaegerPropagator;
+import java.net.URI;
 import java.util.Collections;
 import java.util.Map;
 import org.apache.camel.Endpoint;
 import org.apache.camel.component.aws.sqs.SqsComponent;
 import org.apache.camel.component.aws.sqs.SqsConfiguration;
 import org.apache.camel.component.aws.sqs.SqsEndpoint;
+import org.apache.camel.component.http.HttpComponent;
+import org.apache.camel.component.http.HttpEndpoint;
+import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 
 public class CamelPropagationUtilTest {
 
+  @BeforeAll
+  public static void setUp() {
+    GlobalOpenTelemetry.set(
+        OpenTelemetry.getPropagating(ContextPropagators.create(JaegerPropagator.getInstance())));
+  }
+
+  @Test
+  public void shouldExtractHttpParentForHttpEndpoint() throws Exception {
+
+    // given
+    Endpoint endpoint = new HttpEndpoint("", new HttpComponent(), URI.create(""));
+    Map<String, Object> exchangeHeaders =
+        Collections.singletonMap(
+            "uber-trace-id", "1f7f8dab3f0043b1b9cf0a75caf57510:a13825abcb764bd3:0:1");
+
+    // when
+    Context parent = CamelPropagationUtil.extractParent(exchangeHeaders, endpoint);
+
+    // then
+    Span parentSpan = Span.fromContext(parent);
+    SpanContext parentSpanContext = parentSpan.getSpanContext();
+    assertThat(parentSpanContext.getTraceId()).isEqualTo("1f7f8dab3f0043b1b9cf0a75caf57510");
+    assertThat(parentSpanContext.getSpanId()).isEqualTo("a13825abcb764bd3");
+  }
+
+  @Test
+  public void shouldNotFailExtractingNullHttpParentForHttpEndpoint() throws Exception {
+
+    // given
+    Endpoint endpoint = new HttpEndpoint("", new HttpComponent(), URI.create(""));
+    Map<String, Object> exchangeHeaders = Collections.singletonMap("uber-trace-id", null);
+
+    // when
+    Context parent = CamelPropagationUtil.extractParent(exchangeHeaders, endpoint);
+
+    // then
+    Span parentSpan = Span.fromContext(parent);
+    SpanContext parentSpanContext = parentSpan.getSpanContext();
+    assertThat(parentSpanContext.isValid()).isEqualTo(false);
+  }
+
+  @Test
+  public void shouldNotFailExtractingNullAwsParentForSqsEndpoint() {
+
+    // given
+    Endpoint endpoint = new SqsEndpoint("", new SqsComponent(), new SqsConfiguration());
+    Map<String, Object> exchangeHeaders = Collections.singletonMap("AWSTraceHeader", null);
+
+    // when
+    Context parent = CamelPropagationUtil.extractParent(exchangeHeaders, endpoint);
+
+    // then
+    Span parentSpan = Span.fromContext(parent);
+    SpanContext parentSpanContext = parentSpan.getSpanContext();
+    assertThat(parentSpanContext.isValid()).isEqualTo(false);
+  }
+
   @Test
-  public void shouldExtractAwsParent() {
+  public void shouldExtractAwsParentForSqsEndpoint() {
 
     // given
     Endpoint endpoint = new SqsEndpoint("", new SqsComponent(), new SqsConfiguration());

instrumentation/apache-camel-2.20/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/apachecamel/CamelPropagationUtil.java

@@ -58,8 +58,9 @@ public Iterable<String> keys(Map<String, Object> map) {
     }
 
     @Override
-    public String get(Map<String, Object> map, String s) {
-      return (map.containsKey(s) ? map.get(s).toString() : null);
+    public String get(Map<String, Object> map, String key) {
+      Object value = map.get(key);
+      return (value == null ? null : value.toString());
     }
   }