add default service name

README.md

@@ -18,7 +18,8 @@ To add the extension to the instrumentation agent:
 
      ```bash
      java -javaagent:path/to/opentelemetry-javaagent.jar \
-          -Dotel.javaagent.extensions=build/libs/opentelemetry-javaagent.jar
+          -Dotel.javaagent.extensions=build/libs/opentelemetry-javaagent.jar \
+          -Dotel.service.name="my-service"
           -jar myapp.jar
      ```
 
@@ -36,6 +37,7 @@ To configure TLS
    ```bash
      java -javaagent:path/to/opentelemetry-javaagent.jar \
           -Dotel.javaagent.extensions=build/libs/opentelemetry-javaagent.jar \
+          -Dotel.service.name="my-service" \
           -Djavax.net.ssl.trustStore="path\to\keystore\agent-keystore.jks" \
           -Djavax.net.ssl.trustStorePassword="password"
           -jar myapp.jar

src/main/java/rocks/inspectit/gepard/agent/notify/model/AgentInfo.java

@@ -8,6 +8,7 @@
 import io.opentelemetry.javaagent.tooling.AgentVersion;
 import java.lang.management.ManagementFactory;
 import java.lang.management.RuntimeMXBean;
+import java.util.Objects;
 
 /** Meta-information about the current agent */
 public class AgentInfo {
@@ -30,11 +31,10 @@ public class AgentInfo {
   private final long pid;
 
   private AgentInfo() {
-    InstrumentationConfig config = InstrumentationConfig.get();
-    this.serviceName = config.getString("otel.service.name");
+    this.serviceName = getServiceName();
     this.gepardVersion = "0.0.1";
     this.otelVersion = AgentVersion.VERSION;
-    this.javaVersion = config.getString("java.version");
+    this.javaVersion = System.getProperty("java.version");
     RuntimeMXBean runtime = ManagementFactory.getRuntimeMXBean();
     this.startTime = runtime.getStartTime();
     this.pid = runtime.getPid();
@@ -47,4 +47,18 @@ private AgentInfo() {
   public static String getAsString() throws JsonProcessingException {
     return mapper.writeValueAsString(INFO);
   }
+
+  /**
+   * Returns current service name. If no service name was configured, or it's blank, a default
+   * service name will be returned.
+   *
+   * @return Current service name
+   */
+  private String getServiceName() {
+    InstrumentationConfig config = InstrumentationConfig.get();
+    String serviceName = config.getString("otel.service.name");
+    return Objects.isNull(serviceName) || serviceName.isBlank()
+        ? "inspectit-gepard-agent"
+        : serviceName;
+  }
 }

src/test/java/rocks/inspectit/gepard/agent/notify/model/AgentInfoTest.java

@@ -17,6 +17,7 @@ public void agentInformationContainsProperties() throws JsonProcessingException
     String info = AgentInfo.getAsString();
 
     assertTrue(info.contains("serviceName"));
+    assertTrue(info.contains("inspectit-gepard-agent"));
     assertTrue(info.contains("gepardVersion"));
     assertTrue(info.contains("otelVersion"));
     assertTrue(info.contains("javaVersion"));