Rename the Server-Timing header property

bootstrap/build.gradle

@@ -8,7 +8,7 @@ compileJava {
 
 dependencies {
     // slf4j is included in the otel javaagent, no need to add it here too
-    compileOnly "org.slf4j:slf4j-api:1.7.30"
+    compileOnly deps.slf4j
     // add micrometer to the bootstrap classloader so that it's available in instrumentations
     implementation "io.micrometer:micrometer-core:${versions.micrometer}"
 }

gradle/dependencies.gradle

@@ -16,6 +16,7 @@ ext {
           "com.google.auto.service:auto-service:1.0-rc7",
           "com.google.auto:auto-common:0.8"
       ],
+      slf4j      : "org.slf4j:slf4j-api:1.7.30",
 
       // test
       assertj    : "org.assertj:assertj-core:3.19.0",

instrumentation/common/build.gradle

@@ -3,9 +3,11 @@ plugins {
 }
 
 dependencies {
+    compileOnly deps.slf4j
     compileOnly("io.opentelemetry.instrumentation:opentelemetry-instrumentation-api:${versions.opentelemetryJavaagentAlpha}")
     compileOnly("io.opentelemetry:opentelemetry-api:${versions.opentelemetry}")
 
+    testImplementation deps.slf4j
     testImplementation("io.opentelemetry.javaagent:opentelemetry-testing-common:${versions.opentelemetryJavaagentAlpha}")
 }
 

instrumentation/common/src/main/java/com/splunk/opentelemetry/servertiming/ServerTimingHeader.java

@@ -23,17 +23,24 @@
 import io.opentelemetry.instrumentation.api.config.Config;
 import java.util.HashMap;
 import java.util.Map;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Adds {@code Server-Timing} header (and {@code Access-Control-Expose-Headers}) to the HTTP
  * response. The {@code Server-Timing} header contains the traceId and spanId of the server span.
  */
 public final class ServerTimingHeader {
+  private static final Logger log = LoggerFactory.getLogger(ServerTimingHeader.class);
+
   public static final String SERVER_TIMING = "Server-Timing";
   public static final String EXPOSE_HEADERS = "Access-Control-Expose-Headers";
 
+  private static final String EMIT_RESPONSE_HEADERS_OLD = "splunk.context.server-timing.enabled";
+  private static final String EMIT_RESPONSE_HEADERS = "splunk.trace-response-header.enabled";
+
   public static boolean shouldEmitServerTimingHeader() {
-    return Config.get().getBooleanProperty("splunk.context.server-timing.enabled", false);
+    return ConfigHolder.SHOULD_EMIT_RESPONSE_HEADERS;
   }
 
   public static <RS> void setHeaders(Context context, RS response, TextMapSetter<RS> headerSetter) {
@@ -52,4 +59,22 @@ private static String toHeaderValue(Context context) {
   }
 
   private ServerTimingHeader() {}
+
+  // tests didn't like using Config in ServerTimingHeader.<clinit>
+  static class ConfigHolder {
+    private static final boolean SHOULD_EMIT_RESPONSE_HEADERS;
+
+    static {
+      Config config = Config.get();
+      if (config.getProperty(EMIT_RESPONSE_HEADERS_OLD) != null) {
+        log.warn(
+            "Deprecated property '{}' was set; please use '{}' instead. Support for the deprecated property will be removed in future versions.",
+            EMIT_RESPONSE_HEADERS_OLD,
+            EMIT_RESPONSE_HEADERS);
+      }
+      SHOULD_EMIT_RESPONSE_HEADERS =
+          config.getBooleanProperty(
+              EMIT_RESPONSE_HEADERS, config.getBooleanProperty(EMIT_RESPONSE_HEADERS_OLD, true));
+    }
+  }
 }

instrumentation/netty-3.8/build.gradle

@@ -13,7 +13,3 @@ dependencies {
 
     testImplementation group: 'io.netty', name: 'netty', version: '3.8.0.Final'
 }
-
-tasks.withType(Test) {
-    jvmArgs '-Dsplunk.context.server-timing.enabled=true'
-}

instrumentation/netty-4.0/build.gradle

@@ -13,7 +13,3 @@ dependencies {
 
     testImplementation group: 'io.netty', name: 'netty-codec-http', version: '4.0.0.Final'
 }
-
-tasks.withType(Test) {
-    jvmArgs '-Dsplunk.context.server-timing.enabled=true'
-}

instrumentation/servlet-3-testing/build.gradle

@@ -15,7 +15,3 @@ dependencies {
     testImplementation group: 'org.eclipse.jetty', name: 'jetty-server', version: '8.0.0.v20110901'
     testImplementation group: 'org.eclipse.jetty', name: 'jetty-servlet', version: '8.0.0.v20110901'
 }
-
-tasks.withType(Test) {
-    jvmArgs '-Dsplunk.context.server-timing.enabled=true'
-}

instrumentation/servlet/build.gradle

@@ -21,7 +21,3 @@ dependencies {
         }
     }
 }
-
-tasks.withType(Test) {
-    jvmArgs '-Dsplunk.context.server-timing.enabled=true'
-}