Migrate Netty instrumentation to Decorator

dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/decorator/BaseDecorator.java

@@ -8,6 +8,10 @@ import io.opentracing.Scope;
 import io.opentracing.Span;
 import io.opentracing.tag.Tags;
 import java.lang.reflect.Method;
+import java.net.Inet4Address;
+import java.net.Inet6Address;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.TreeSet;
@@ -86,6 +90,22 @@ public abstract class BaseDecorator {
     return span;
   }
 
+  public Span onPeerConnection(final Span span, final InetSocketAddress remoteConnection) {
+    assert span != null;
+    if (remoteConnection != null) {
+      span.setTag(Tags.PEER_HOSTNAME.getKey(), remoteConnection.getHostName());
+      span.setTag(Tags.PEER_PORT.getKey(), remoteConnection.getPort());
+
+      final InetAddress remoteAddress = remoteConnection.getAddress();
+      if (remoteAddress instanceof Inet4Address) {
+        Tags.PEER_HOST_IPV4.set(span, remoteAddress.getHostAddress());
+      } else if (remoteAddress instanceof Inet6Address) {
+        Tags.PEER_HOST_IPV6.set(span, remoteAddress.getHostAddress());
+      }
+    }
+    return span;
+  }
+
   /**
    * This method is used to generate an acceptable span (operation) name based on a given method
    * reference. Anonymous classes are named based on their parent.

dd-java-agent/agent-tooling/src/test/groovy/datadog/trace/agent/decorator/BaseDecoratorTest.groovy

@@ -28,6 +28,28 @@ class BaseDecoratorTest extends Specification {
     0 * _
   }
 
+  def "test onPeerConnection"() {
+    when:
+    decorator.onPeerConnection(span, connection)
+
+    then:
+    1 * span.setTag(Tags.PEER_HOSTNAME.key, connection.hostName)
+    1 * span.setTag(Tags.PEER_PORT.key, connection.port)
+    if (connection.address instanceof Inet4Address) {
+      1 * span.setTag(Tags.PEER_HOST_IPV4.key, connection.address.hostAddress)
+    }
+    if (connection.address instanceof Inet6Address) {
+      1 * span.setTag(Tags.PEER_HOST_IPV6.key, connection.address.hostAddress)
+    }
+    0 * _
+
+    where:
+    connection                                      | _
+    new InetSocketAddress("localhost", 888)         | _
+    new InetSocketAddress("ipv6.google.com", 999)   | _
+    new InetSocketAddress("bad.address.local", 999) | _
+  }
+
   def "test onError"() {
     when:
     decorator.onError(span, error)
@@ -64,6 +86,12 @@ class BaseDecoratorTest extends Specification {
     then:
     thrown(AssertionError)
 
+    when:
+    decorator.onPeerConnection((Span) null, null)
+
+    then:
+    thrown(AssertionError)
+
     when:
     decorator.beforeFinish((Span) null)
 

dd-java-agent/instrumentation/aws-java-sdk-2.2/src/test/groovy/AwsClientTest.groovy

@@ -193,6 +193,7 @@ class AwsClientTest extends AgentTestRunner {
             "$Tags.HTTP_STATUS.key" 200
             "$Tags.HTTP_URL.key" expectedUrl
             "$Tags.PEER_HOSTNAME.key" "localhost"
+            "$Tags.PEER_HOST_IPV4.key" "127.0.0.1"
             "$Tags.PEER_PORT.key" server.address.port
             "$Tags.HTTP_METHOD.key" "$method"
             "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_CLIENT

dd-java-agent/instrumentation/netty-4.0/src/main/java/datadog/trace/instrumentation/netty40/ChannelFutureListenerInstrumentation.java

@@ -42,7 +42,11 @@ public class ChannelFutureListenerInstrumentation extends Instrumenter.Default {
   public String[] helperClassNames() {
     return new String[] {
       packageName + ".AttributeKeys",
+      "datadog.trace.agent.decorator.BaseDecorator",
       // server helpers
+      "datadog.trace.agent.decorator.ServerDecorator",
+      "datadog.trace.agent.decorator.HttpServerDecorator",
+      packageName + ".server.NettyHttpServerDecorator",
       packageName + ".server.NettyRequestExtractAdapter",
       packageName + ".server.HttpServerRequestTracingHandler",
       packageName + ".server.HttpServerResponseTracingHandler",

dd-java-agent/instrumentation/netty-4.0/src/main/java/datadog/trace/instrumentation/netty40/NettyChannelPipelineInstrumentation.java

@@ -56,12 +56,19 @@ public class NettyChannelPipelineInstrumentation extends Instrumenter.Default {
   public String[] helperClassNames() {
     return new String[] {
       packageName + ".AttributeKeys",
+      "datadog.trace.agent.decorator.BaseDecorator",
       // client helpers
+      "datadog.trace.agent.decorator.ClientDecorator",
+      "datadog.trace.agent.decorator.HttpClientDecorator",
+      packageName + ".client.NettyHttpClientDecorator",
       packageName + ".client.NettyResponseInjectAdapter",
       packageName + ".client.HttpClientRequestTracingHandler",
       packageName + ".client.HttpClientResponseTracingHandler",
       packageName + ".client.HttpClientTracingHandler",
       // server helpers
+      "datadog.trace.agent.decorator.ServerDecorator",
+      "datadog.trace.agent.decorator.HttpServerDecorator",
+      packageName + ".server.NettyHttpServerDecorator",
       packageName + ".server.NettyRequestExtractAdapter",
       packageName + ".server.HttpServerRequestTracingHandler",
       packageName + ".server.HttpServerResponseTracingHandler",

dd-java-agent/instrumentation/netty-4.0/src/main/java/datadog/trace/instrumentation/netty40/client/HttpClientRequestTracingHandler.java

@@ -1,10 +1,7 @@
 package datadog.trace.instrumentation.netty40.client;
 
-import static io.netty.handler.codec.http.HttpHeaders.Names.HOST;
+import static datadog.trace.instrumentation.netty40.client.NettyHttpClientDecorator.DECORATE;
-import static io.opentracing.log.Fields.ERROR_OBJECT;
 
-import datadog.trace.api.DDSpanTypes;
-import datadog.trace.api.DDTags;
 import datadog.trace.context.TraceScope;
 import datadog.trace.instrumentation.netty40.AttributeKeys;
 import io.netty.channel.ChannelHandlerContext;
@@ -13,12 +10,8 @@ import io.netty.channel.ChannelPromise;
 import io.netty.handler.codec.http.HttpRequest;
 import io.opentracing.Span;
 import io.opentracing.propagation.Format;
-import io.opentracing.tag.Tags;
 import io.opentracing.util.GlobalTracer;
 import java.net.InetSocketAddress;
-import java.net.URI;
-import java.net.URISyntaxException;
-import java.util.Collections;
 import lombok.extern.slf4j.Slf4j;
 
 @Slf4j
@@ -39,19 +32,11 @@ public class HttpClientRequestTracingHandler extends ChannelOutboundHandlerAdapt
     }
 
     final HttpRequest request = (HttpRequest) msg;
-    final InetSocketAddress remoteAddress = (InetSocketAddress) ctx.channel().remoteAddress();
 
-    final Span span =
+    final Span span = GlobalTracer.get().buildSpan("netty.client.request").start();
-        GlobalTracer.get()
+    DECORATE.afterStart(span);
-            .buildSpan("netty.client.request")
+    DECORATE.onRequest(span, request);
-            .withTag(Tags.SPAN_KIND.getKey(), Tags.SPAN_KIND_CLIENT)
+    DECORATE.onPeerConnection(span, (InetSocketAddress) ctx.channel().remoteAddress());
-            .withTag(Tags.PEER_HOSTNAME.getKey(), remoteAddress.getHostName())
-            .withTag(Tags.PEER_PORT.getKey(), remoteAddress.getPort())
-            .withTag(Tags.HTTP_METHOD.getKey(), request.getMethod().name())
-            .withTag(Tags.HTTP_URL.getKey(), formatUrl(request))
-            .withTag(Tags.COMPONENT.getKey(), "netty-client")
-            .withTag(DDTags.SPAN_TYPE, DDSpanTypes.HTTP_CLIENT)
-            .start();
 
     // AWS calls are often signed, so we can't add headers without breaking the signature.
     if (!request.headers().contains("amz-sdk-invocation-id")) {
@@ -65,9 +50,9 @@ public class HttpClientRequestTracingHandler extends ChannelOutboundHandlerAdapt
     try {
       ctx.write(msg, prm);
     } catch (final Throwable throwable) {
-      Tags.ERROR.set(span, Boolean.TRUE);
+      DECORATE.onError(span, throwable);
-      span.log(Collections.singletonMap(ERROR_OBJECT, throwable));
+      DECORATE.beforeFinish(span);
-      span.finish(); // Finish the span manually since finishSpanOnClose was false
+      span.finish();
       throw throwable;
     }
 
@@ -75,18 +60,4 @@ public class HttpClientRequestTracingHandler extends ChannelOutboundHandlerAdapt
       scope.close();
     }
   }
-
-  private String formatUrl(final HttpRequest request) {
-    try {
-      URI uri = new URI(request.getUri());
-      if ((uri.getHost() == null || uri.getHost().equals("")) && request.headers().contains(HOST)) {
-        uri = new URI("http://" + request.headers().get(HOST) + request.getUri());
-      }
-      return new URI(uri.getScheme(), null, uri.getHost(), uri.getPort(), uri.getPath(), null, null)
-          .toString();
-    } catch (final URISyntaxException e) {
-      log.debug("Cannot parse netty uri: {}", request.getUri());
-      return request.getUri();
-    }
-  }
 }

dd-java-agent/instrumentation/netty-4.0/src/main/java/datadog/trace/instrumentation/netty40/client/HttpClientResponseTracingHandler.java

@@ -1,6 +1,6 @@
 package datadog.trace.instrumentation.netty40.client;
 
-import static io.opentracing.log.Fields.ERROR_OBJECT;
+import static datadog.trace.instrumentation.netty40.client.NettyHttpClientDecorator.DECORATE;
 
 import datadog.trace.context.TraceScope;
 import datadog.trace.instrumentation.netty40.AttributeKeys;
@@ -11,7 +11,6 @@ import io.opentracing.Scope;
 import io.opentracing.Span;
 import io.opentracing.tag.Tags;
 import io.opentracing.util.GlobalTracer;
-import java.util.Collections;
 
 public class HttpClientResponseTracingHandler extends ChannelInboundHandlerAdapter {
 
@@ -33,8 +32,8 @@ public class HttpClientResponseTracingHandler extends ChannelInboundHandlerAdapt
         ctx.fireChannelRead(msg);
       } catch (final Throwable throwable) {
         if (finishSpan) {
-          Tags.ERROR.set(span, Boolean.TRUE);
+          DECORATE.onError(span, throwable);
-          span.log(Collections.singletonMap(ERROR_OBJECT, throwable));
+          DECORATE.beforeFinish(span);
           Tags.HTTP_STATUS.set(span, 500);
           span.finish(); // Finish the span manually since finishSpanOnClose was false
           throw throwable;
@@ -42,7 +41,8 @@ public class HttpClientResponseTracingHandler extends ChannelInboundHandlerAdapt
       }
 
       if (finishSpan) {
-        Tags.HTTP_STATUS.set(span, ((HttpResponse) msg).getStatus().code());
+        DECORATE.onResponse(span, (HttpResponse) msg);
+        DECORATE.beforeFinish(span);
         span.finish(); // Finish the span manually since finishSpanOnClose was false
       }
     }

dd-java-agent/instrumentation/netty-4.0/src/main/java/datadog/trace/instrumentation/netty40/client/NettyHttpClientDecorator.java

@@ -0,0 +1,61 @@
+package datadog.trace.instrumentation.netty40.client;
+
+import static io.netty.handler.codec.http.HttpHeaders.Names.HOST;
+
+import datadog.trace.agent.decorator.HttpClientDecorator;
+import io.netty.handler.codec.http.HttpRequest;
+import io.netty.handler.codec.http.HttpResponse;
+import java.net.URI;
+import java.net.URISyntaxException;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class NettyHttpClientDecorator extends HttpClientDecorator<HttpRequest, HttpResponse> {
+  public static final NettyHttpClientDecorator DECORATE = new NettyHttpClientDecorator();
+
+  @Override
+  protected String[] instrumentationNames() {
+    return new String[] {"netty", "netty-4.0"};
+  }
+
+  @Override
+  protected String component() {
+    return "netty-client";
+  }
+
+  @Override
+  protected String method(final HttpRequest httpRequest) {
+    return httpRequest.getMethod().name();
+  }
+
+  @Override
+  protected String url(final HttpRequest request) {
+    // FIXME: This code is duplicated across netty integrations.
+    try {
+      URI uri = new URI(request.getUri());
+      if ((uri.getHost() == null || uri.getHost().equals("")) && request.headers().contains(HOST)) {
+        uri = new URI("http://" + request.headers().get(HOST) + request.getUri());
+      }
+      return new URI(uri.getScheme(), null, uri.getHost(), uri.getPort(), uri.getPath(), null, null)
+          .toString();
+    } catch (final URISyntaxException e) {
+      log.debug("Cannot parse netty uri: {}", request.getUri());
+      return request.getUri();
+    }
+  }
+
+  @Override
+  protected String hostname(final HttpRequest httpRequest) {
+    return null;
+  }
+
+  @Override
+  protected Integer port(final HttpRequest httpRequest) {
+    return null;
+  }
+
+  @Override
+  protected Integer status(final HttpResponse httpResponse) {
+    return httpResponse.getStatus().code();
+  }
+}

dd-java-agent/instrumentation/netty-4.0/src/main/java/datadog/trace/instrumentation/netty40/server/HttpServerRequestTracingHandler.java

@@ -1,10 +1,7 @@
 package datadog.trace.instrumentation.netty40.server;
 
-import static io.netty.handler.codec.http.HttpHeaders.Names.HOST;
+import static datadog.trace.instrumentation.netty40.server.NettyHttpServerDecorator.DECORATE;
-import static io.opentracing.log.Fields.ERROR_OBJECT;
 
-import datadog.trace.api.DDSpanTypes;
-import datadog.trace.api.DDTags;
 import datadog.trace.context.TraceScope;
 import datadog.trace.instrumentation.netty40.AttributeKeys;
 import io.netty.channel.ChannelHandlerContext;
@@ -14,10 +11,8 @@ import io.opentracing.Scope;
 import io.opentracing.Span;
 import io.opentracing.SpanContext;
 import io.opentracing.propagation.Format;
-import io.opentracing.tag.Tags;
 import io.opentracing.util.GlobalTracer;
 import java.net.InetSocketAddress;
-import java.util.Collections;
 
 public class HttpServerRequestTracingHandler extends ChannelInboundHandlerAdapter {
 
@@ -34,35 +29,27 @@ public class HttpServerRequestTracingHandler extends ChannelInboundHandlerAdapte
         GlobalTracer.get()
             .extract(Format.Builtin.HTTP_HEADERS, new NettyRequestExtractAdapter(request));
 
-    String url = request.getUri();
-    if (request.headers().contains(HOST)) {
-      url = "http://" + request.headers().get(HOST) + url;
-    }
     final Scope scope =
         GlobalTracer.get()
             .buildSpan("netty.request")
             .asChildOf(extractedContext)
-            .withTag(Tags.SPAN_KIND.getKey(), Tags.SPAN_KIND_SERVER)
-            .withTag(Tags.PEER_HOSTNAME.getKey(), remoteAddress.getHostName())
-            .withTag(Tags.PEER_PORT.getKey(), remoteAddress.getPort())
-            .withTag(Tags.HTTP_METHOD.getKey(), request.getMethod().name())
-            .withTag(Tags.HTTP_URL.getKey(), url)
-            .withTag(Tags.COMPONENT.getKey(), "netty")
-            .withTag(DDTags.SPAN_TYPE, DDSpanTypes.HTTP_SERVER)
             .startActive(false);
+    final Span span = scope.span();
+    DECORATE.afterStart(span);
+    DECORATE.onRequest(span, request);
+    DECORATE.onPeerConnection(span, remoteAddress);
 
     if (scope instanceof TraceScope) {
       ((TraceScope) scope).setAsyncPropagation(true);
     }
 
-    final Span span = scope.span();
     ctx.channel().attr(AttributeKeys.SERVER_ATTRIBUTE_KEY).set(span);
 
     try {
       ctx.fireChannelRead(msg);
     } catch (final Throwable throwable) {
-      Tags.ERROR.set(span, Boolean.TRUE);
+      DECORATE.onError(span, throwable);
-      span.log(Collections.singletonMap(ERROR_OBJECT, throwable));
+      DECORATE.beforeFinish(span);
       span.finish(); // Finish the span manually since finishSpanOnClose was false
       throw throwable;
     } finally {

dd-java-agent/instrumentation/netty-4.0/src/main/java/datadog/trace/instrumentation/netty40/server/HttpServerResponseTracingHandler.java

@@ -1,6 +1,6 @@
 package datadog.trace.instrumentation.netty40.server;
 
-import static io.opentracing.log.Fields.ERROR_OBJECT;
+import static datadog.trace.instrumentation.netty40.server.NettyHttpServerDecorator.DECORATE;
 
 import datadog.trace.instrumentation.netty40.AttributeKeys;
 import io.netty.channel.ChannelHandlerContext;
@@ -9,7 +9,6 @@ import io.netty.channel.ChannelPromise;
 import io.netty.handler.codec.http.HttpResponse;
 import io.opentracing.Span;
 import io.opentracing.tag.Tags;
-import java.util.Collections;
 
 public class HttpServerResponseTracingHandler extends ChannelOutboundHandlerAdapter {
 
@@ -26,14 +25,13 @@ public class HttpServerResponseTracingHandler extends ChannelOutboundHandlerAdap
     try {
       ctx.write(msg, prm);
     } catch (final Throwable throwable) {
-      Tags.ERROR.set(span, Boolean.TRUE);
+      DECORATE.onError(span, throwable);
-      span.log(Collections.singletonMap(ERROR_OBJECT, throwable));
       Tags.HTTP_STATUS.set(span, 500);
       span.finish(); // Finish the span manually since finishSpanOnClose was false
       throw throwable;
     }
-
+    DECORATE.onResponse(span, response);
-    Tags.HTTP_STATUS.set(span, response.getStatus().code());
+    DECORATE.beforeFinish(span);
     span.finish(); // Finish the span manually since finishSpanOnClose was false
   }
 }

dd-java-agent/instrumentation/netty-4.0/src/main/java/datadog/trace/instrumentation/netty40/server/NettyHttpServerDecorator.java

@@ -0,0 +1,61 @@
+package datadog.trace.instrumentation.netty40.server;
+
+import static io.netty.handler.codec.http.HttpHeaders.Names.HOST;
+
+import datadog.trace.agent.decorator.HttpServerDecorator;
+import io.netty.handler.codec.http.HttpRequest;
+import io.netty.handler.codec.http.HttpResponse;
+import java.net.URI;
+import java.net.URISyntaxException;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class NettyHttpServerDecorator extends HttpServerDecorator<HttpRequest, HttpResponse> {
+  public static final NettyHttpServerDecorator DECORATE = new NettyHttpServerDecorator();
+
+  @Override
+  protected String[] instrumentationNames() {
+    return new String[] {"netty", "netty-4.0"};
+  }
+
+  @Override
+  protected String component() {
+    return "netty";
+  }
+
+  @Override
+  protected String method(final HttpRequest httpRequest) {
+    return httpRequest.getMethod().name();
+  }
+
+  @Override
+  protected String url(final HttpRequest request) {
+    // FIXME: This code is duplicated across netty integrations.
+    try {
+      URI uri = new URI(request.getUri());
+      if ((uri.getHost() == null || uri.getHost().equals("")) && request.headers().contains(HOST)) {
+        uri = new URI("http://" + request.headers().get(HOST) + request.getUri());
+      }
+      return new URI(uri.getScheme(), null, uri.getHost(), uri.getPort(), uri.getPath(), null, null)
+          .toString();
+    } catch (final URISyntaxException e) {
+      log.debug("Cannot parse netty uri: {}", request.getUri());
+      return request.getUri();
+    }
+  }
+
+  @Override
+  protected String hostname(final HttpRequest httpRequest) {
+    return null;
+  }
+
+  @Override
+  protected Integer port(final HttpRequest httpRequest) {
+    return null;
+  }
+
+  @Override
+  protected Integer status(final HttpResponse httpResponse) {
+    return httpResponse.getStatus().code();
+  }
+}

dd-java-agent/instrumentation/netty-4.0/src/test/groovy/Netty40ClientTest.groovy

@@ -57,7 +57,8 @@ class Netty40ClientTest extends AgentTestRunner {
             "$Tags.HTTP_STATUS.key" 200
             "$Tags.HTTP_URL.key" "$server.address/"
             "$Tags.PEER_HOSTNAME.key" "localhost"
-            "$Tags.PEER_PORT.key" Integer
+            "$Tags.PEER_HOST_IPV4.key" "127.0.0.1"
+            "$Tags.PEER_PORT.key" server.address.port
             "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_CLIENT
             defaultTags()
           }

dd-java-agent/instrumentation/netty-4.0/src/test/groovy/Netty40ServerTest.groovy

@@ -13,7 +13,6 @@ import io.netty.channel.nio.NioEventLoopGroup
 import io.netty.channel.socket.nio.NioServerSocketChannel
 import io.netty.handler.codec.http.DefaultFullHttpResponse
 import io.netty.handler.codec.http.FullHttpResponse
-import io.netty.handler.codec.http.HttpHeaders
 import io.netty.handler.codec.http.HttpRequestDecoder
 import io.netty.handler.codec.http.HttpResponseEncoder
 import io.netty.handler.codec.http.HttpResponseStatus
@@ -26,9 +25,14 @@ import io.netty.util.CharsetUtil
 import io.opentracing.tag.Tags
 import okhttp3.OkHttpClient
 import okhttp3.Request
+import spock.lang.Shared
+
+import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_LENGTH
+import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_TYPE
 
 class Netty40ServerTest extends AgentTestRunner {
 
+  @Shared
   OkHttpClient client = OkHttpUtils.client()
 
   def "test server request/response"() {
@@ -66,6 +70,7 @@ class Netty40ServerTest extends AgentTestRunner {
             "$Tags.HTTP_STATUS.key" 200
             "$Tags.HTTP_URL.key" "http://localhost:$port/"
             "$Tags.PEER_HOSTNAME.key" "localhost"
+            "$Tags.PEER_HOST_IPV4.key" "127.0.0.1"
             "$Tags.PEER_PORT.key" Integer
             "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             defaultTags(true)
@@ -111,6 +116,7 @@ class Netty40ServerTest extends AgentTestRunner {
             "$Tags.HTTP_STATUS.key" responseCode.code()
             "$Tags.HTTP_URL.key" "http://localhost:$port/"
             "$Tags.PEER_HOSTNAME.key" "localhost"
+            "$Tags.PEER_HOST_IPV4.key" "127.0.0.1"
             "$Tags.PEER_PORT.key" Integer
             "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             if (error) {
@@ -145,8 +151,8 @@ class Netty40ServerTest extends AgentTestRunner {
             if (msg instanceof LastHttpContent) {
               ByteBuf content = Unpooled.copiedBuffer("Hello World", CharsetUtil.UTF_8)
               FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, responseCode, content)
-              response.headers().set(HttpHeaders.Names.CONTENT_TYPE, "text/plain")
+              response.headers().set(CONTENT_TYPE, "text/plain")
-              response.headers().set(HttpHeaders.Names.CONTENT_LENGTH, content.readableBytes())
+              response.headers().set(CONTENT_LENGTH, content.readableBytes())
               ctx.write(response)
             }
           },

dd-java-agent/instrumentation/netty-4.1/src/main/java/datadog/trace/instrumentation/netty41/ChannelFutureListenerInstrumentation.java

@@ -42,7 +42,11 @@ public class ChannelFutureListenerInstrumentation extends Instrumenter.Default {
   public String[] helperClassNames() {
     return new String[] {
       packageName + ".AttributeKeys",
+      "datadog.trace.agent.decorator.BaseDecorator",
       // server helpers
+      "datadog.trace.agent.decorator.ServerDecorator",
+      "datadog.trace.agent.decorator.HttpServerDecorator",
+      packageName + ".server.NettyHttpServerDecorator",
       packageName + ".server.NettyRequestExtractAdapter",
       packageName + ".server.HttpServerRequestTracingHandler",
       packageName + ".server.HttpServerResponseTracingHandler",

dd-java-agent/instrumentation/netty-4.1/src/main/java/datadog/trace/instrumentation/netty41/NettyChannelPipelineInstrumentation.java

@@ -56,12 +56,19 @@ public class NettyChannelPipelineInstrumentation extends Instrumenter.Default {
   public String[] helperClassNames() {
     return new String[] {
       packageName + ".AttributeKeys",
+      "datadog.trace.agent.decorator.BaseDecorator",
       // client helpers
+      "datadog.trace.agent.decorator.ClientDecorator",
+      "datadog.trace.agent.decorator.HttpClientDecorator",
+      packageName + ".client.NettyHttpClientDecorator",
       packageName + ".client.NettyResponseInjectAdapter",
       packageName + ".client.HttpClientRequestTracingHandler",
       packageName + ".client.HttpClientResponseTracingHandler",
       packageName + ".client.HttpClientTracingHandler",
       // server helpers
+      "datadog.trace.agent.decorator.ServerDecorator",
+      "datadog.trace.agent.decorator.HttpServerDecorator",
+      packageName + ".server.NettyHttpServerDecorator",
       packageName + ".server.NettyRequestExtractAdapter",
       packageName + ".server.HttpServerRequestTracingHandler",
       packageName + ".server.HttpServerResponseTracingHandler",

dd-java-agent/instrumentation/netty-4.1/src/main/java/datadog/trace/instrumentation/netty41/client/HttpClientRequestTracingHandler.java

@@ -1,10 +1,7 @@
 package datadog.trace.instrumentation.netty41.client;
 
-import static io.netty.handler.codec.http.HttpHeaderNames.HOST;
+import static datadog.trace.instrumentation.netty41.client.NettyHttpClientDecorator.DECORATE;
-import static io.opentracing.log.Fields.ERROR_OBJECT;
 
-import datadog.trace.api.DDSpanTypes;
-import datadog.trace.api.DDTags;
 import datadog.trace.context.TraceScope;
 import datadog.trace.instrumentation.netty41.AttributeKeys;
 import io.netty.channel.ChannelHandlerContext;
@@ -13,12 +10,8 @@ import io.netty.channel.ChannelPromise;
 import io.netty.handler.codec.http.HttpRequest;
 import io.opentracing.Span;
 import io.opentracing.propagation.Format;
-import io.opentracing.tag.Tags;
 import io.opentracing.util.GlobalTracer;
 import java.net.InetSocketAddress;
-import java.net.URI;
-import java.net.URISyntaxException;
-import java.util.Collections;
 import lombok.extern.slf4j.Slf4j;
 
 @Slf4j
@@ -39,19 +32,11 @@ public class HttpClientRequestTracingHandler extends ChannelOutboundHandlerAdapt
     }
 
     final HttpRequest request = (HttpRequest) msg;
-    final InetSocketAddress remoteAddress = (InetSocketAddress) ctx.channel().remoteAddress();
 
-    final Span span =
+    final Span span = GlobalTracer.get().buildSpan("netty.client.request").start();
-        GlobalTracer.get()
+    DECORATE.afterStart(span);
-            .buildSpan("netty.client.request")
+    DECORATE.onRequest(span, request);
-            .withTag(Tags.SPAN_KIND.getKey(), Tags.SPAN_KIND_CLIENT)
+    DECORATE.onPeerConnection(span, (InetSocketAddress) ctx.channel().remoteAddress());
-            .withTag(Tags.PEER_HOSTNAME.getKey(), remoteAddress.getHostName())
-            .withTag(Tags.PEER_PORT.getKey(), remoteAddress.getPort())
-            .withTag(Tags.HTTP_METHOD.getKey(), request.method().name())
-            .withTag(Tags.HTTP_URL.getKey(), formatUrl(request))
-            .withTag(Tags.COMPONENT.getKey(), "netty-client")
-            .withTag(DDTags.SPAN_TYPE, DDSpanTypes.HTTP_CLIENT)
-            .start();
 
     // AWS calls are often signed, so we can't add headers without breaking the signature.
     if (!request.headers().contains("amz-sdk-invocation-id")) {
@@ -65,9 +50,9 @@ public class HttpClientRequestTracingHandler extends ChannelOutboundHandlerAdapt
     try {
       ctx.write(msg, prm);
     } catch (final Throwable throwable) {
-      Tags.ERROR.set(span, Boolean.TRUE);
+      DECORATE.onError(span, throwable);
-      span.log(Collections.singletonMap(ERROR_OBJECT, throwable));
+      DECORATE.beforeFinish(span);
-      span.finish(); // Finish the span manually since finishSpanOnClose was false
+      span.finish();
       throw throwable;
     }
 
@@ -75,18 +60,4 @@ public class HttpClientRequestTracingHandler extends ChannelOutboundHandlerAdapt
       scope.close();
     }
   }
-
-  private String formatUrl(final HttpRequest request) {
-    try {
-      URI uri = new URI(request.uri());
-      if ((uri.getHost() == null || uri.getHost().equals("")) && request.headers().contains(HOST)) {
-        uri = new URI("http://" + request.headers().get(HOST) + request.uri());
-      }
-      return new URI(uri.getScheme(), null, uri.getHost(), uri.getPort(), uri.getPath(), null, null)
-          .toString();
-    } catch (final URISyntaxException e) {
-      log.debug("Cannot parse netty uri: {}", request.uri());
-      return request.uri();
-    }
-  }
 }

dd-java-agent/instrumentation/netty-4.1/src/main/java/datadog/trace/instrumentation/netty41/client/HttpClientResponseTracingHandler.java

@@ -1,6 +1,6 @@
 package datadog.trace.instrumentation.netty41.client;
 
-import static io.opentracing.log.Fields.ERROR_OBJECT;
+import static datadog.trace.instrumentation.netty41.client.NettyHttpClientDecorator.DECORATE;
 
 import datadog.trace.context.TraceScope;
 import datadog.trace.instrumentation.netty41.AttributeKeys;
@@ -11,7 +11,6 @@ import io.opentracing.Scope;
 import io.opentracing.Span;
 import io.opentracing.tag.Tags;
 import io.opentracing.util.GlobalTracer;
-import java.util.Collections;
 
 public class HttpClientResponseTracingHandler extends ChannelInboundHandlerAdapter {
 
@@ -33,8 +32,8 @@ public class HttpClientResponseTracingHandler extends ChannelInboundHandlerAdapt
         ctx.fireChannelRead(msg);
       } catch (final Throwable throwable) {
         if (finishSpan) {
-          Tags.ERROR.set(span, Boolean.TRUE);
+          DECORATE.onError(span, throwable);
-          span.log(Collections.singletonMap(ERROR_OBJECT, throwable));
+          DECORATE.beforeFinish(span);
           Tags.HTTP_STATUS.set(span, 500);
           span.finish(); // Finish the span manually since finishSpanOnClose was false
           throw throwable;
@@ -42,7 +41,8 @@ public class HttpClientResponseTracingHandler extends ChannelInboundHandlerAdapt
       }
 
       if (finishSpan) {
-        Tags.HTTP_STATUS.set(span, ((HttpResponse) msg).status().code());
+        DECORATE.onResponse(span, (HttpResponse) msg);
+        DECORATE.beforeFinish(span);
         span.finish(); // Finish the span manually since finishSpanOnClose was false
       }
     }

dd-java-agent/instrumentation/netty-4.1/src/main/java/datadog/trace/instrumentation/netty41/client/NettyHttpClientDecorator.java

@@ -0,0 +1,61 @@
+package datadog.trace.instrumentation.netty41.client;
+
+import static io.netty.handler.codec.http.HttpHeaders.Names.HOST;
+
+import datadog.trace.agent.decorator.HttpClientDecorator;
+import io.netty.handler.codec.http.HttpRequest;
+import io.netty.handler.codec.http.HttpResponse;
+import java.net.URI;
+import java.net.URISyntaxException;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class NettyHttpClientDecorator extends HttpClientDecorator<HttpRequest, HttpResponse> {
+  public static final NettyHttpClientDecorator DECORATE = new NettyHttpClientDecorator();
+
+  @Override
+  protected String[] instrumentationNames() {
+    return new String[] {"netty", "netty-4.0"};
+  }
+
+  @Override
+  protected String component() {
+    return "netty-client";
+  }
+
+  @Override
+  protected String method(final HttpRequest httpRequest) {
+    return httpRequest.method().name();
+  }
+
+  @Override
+  protected String url(final HttpRequest request) {
+    // FIXME: This code is duplicated across netty integrations.
+    try {
+      URI uri = new URI(request.uri());
+      if ((uri.getHost() == null || uri.getHost().equals("")) && request.headers().contains(HOST)) {
+        uri = new URI("http://" + request.headers().get(HOST) + request.uri());
+      }
+      return new URI(uri.getScheme(), null, uri.getHost(), uri.getPort(), uri.getPath(), null, null)
+          .toString();
+    } catch (final URISyntaxException e) {
+      log.debug("Cannot parse netty uri: {}", request.uri());
+      return request.uri();
+    }
+  }
+
+  @Override
+  protected String hostname(final HttpRequest httpRequest) {
+    return null;
+  }
+
+  @Override
+  protected Integer port(final HttpRequest httpRequest) {
+    return null;
+  }
+
+  @Override
+  protected Integer status(final HttpResponse httpResponse) {
+    return httpResponse.status().code();
+  }
+}

dd-java-agent/instrumentation/netty-4.1/src/main/java/datadog/trace/instrumentation/netty41/server/HttpServerRequestTracingHandler.java

@@ -1,10 +1,7 @@
 package datadog.trace.instrumentation.netty41.server;
 
-import static io.netty.handler.codec.http.HttpHeaderNames.HOST;
+import static datadog.trace.instrumentation.netty41.server.NettyHttpServerDecorator.DECORATE;
-import static io.opentracing.log.Fields.ERROR_OBJECT;
 
-import datadog.trace.api.DDSpanTypes;
-import datadog.trace.api.DDTags;
 import datadog.trace.context.TraceScope;
 import datadog.trace.instrumentation.netty41.AttributeKeys;
 import io.netty.channel.ChannelHandlerContext;
@@ -14,10 +11,8 @@ import io.opentracing.Scope;
 import io.opentracing.Span;
 import io.opentracing.SpanContext;
 import io.opentracing.propagation.Format;
-import io.opentracing.tag.Tags;
 import io.opentracing.util.GlobalTracer;
 import java.net.InetSocketAddress;
-import java.util.Collections;
 
 public class HttpServerRequestTracingHandler extends ChannelInboundHandlerAdapter {
 
@@ -34,35 +29,27 @@ public class HttpServerRequestTracingHandler extends ChannelInboundHandlerAdapte
         GlobalTracer.get()
             .extract(Format.Builtin.HTTP_HEADERS, new NettyRequestExtractAdapter(request));
 
-    String url = request.uri();
-    if (request.headers().contains(HOST)) {
-      url = "http://" + request.headers().get(HOST) + url;
-    }
     final Scope scope =
         GlobalTracer.get()
             .buildSpan("netty.request")
             .asChildOf(extractedContext)
-            .withTag(Tags.SPAN_KIND.getKey(), Tags.SPAN_KIND_SERVER)
-            .withTag(Tags.PEER_HOSTNAME.getKey(), remoteAddress.getHostName())
-            .withTag(Tags.PEER_PORT.getKey(), remoteAddress.getPort())
-            .withTag(Tags.HTTP_METHOD.getKey(), request.method().name())
-            .withTag(Tags.HTTP_URL.getKey(), url)
-            .withTag(Tags.COMPONENT.getKey(), "netty")
-            .withTag(DDTags.SPAN_TYPE, DDSpanTypes.HTTP_SERVER)
             .startActive(false);
+    final Span span = scope.span();
+    DECORATE.afterStart(span);
+    DECORATE.onRequest(span, request);
+    DECORATE.onPeerConnection(span, remoteAddress);
 
     if (scope instanceof TraceScope) {
       ((TraceScope) scope).setAsyncPropagation(true);
     }
 
-    final Span span = scope.span();
     ctx.channel().attr(AttributeKeys.SERVER_ATTRIBUTE_KEY).set(span);
 
     try {
       ctx.fireChannelRead(msg);
     } catch (final Throwable throwable) {
-      Tags.ERROR.set(span, Boolean.TRUE);
+      DECORATE.onError(span, throwable);
-      span.log(Collections.singletonMap(ERROR_OBJECT, throwable));
+      DECORATE.beforeFinish(span);
       span.finish(); // Finish the span manually since finishSpanOnClose was false
       throw throwable;
     } finally {

dd-java-agent/instrumentation/netty-4.1/src/main/java/datadog/trace/instrumentation/netty41/server/HttpServerResponseTracingHandler.java

@@ -1,6 +1,6 @@
 package datadog.trace.instrumentation.netty41.server;
 
-import static io.opentracing.log.Fields.ERROR_OBJECT;
+import static datadog.trace.instrumentation.netty41.server.NettyHttpServerDecorator.DECORATE;
 
 import datadog.trace.instrumentation.netty41.AttributeKeys;
 import io.netty.channel.ChannelHandlerContext;
@@ -9,7 +9,6 @@ import io.netty.channel.ChannelPromise;
 import io.netty.handler.codec.http.HttpResponse;
 import io.opentracing.Span;
 import io.opentracing.tag.Tags;
-import java.util.Collections;
 
 public class HttpServerResponseTracingHandler extends ChannelOutboundHandlerAdapter {
 
@@ -26,14 +25,13 @@ public class HttpServerResponseTracingHandler extends ChannelOutboundHandlerAdap
     try {
       ctx.write(msg, prm);
     } catch (final Throwable throwable) {
-      Tags.ERROR.set(span, Boolean.TRUE);
+      DECORATE.onError(span, throwable);
-      span.log(Collections.singletonMap(ERROR_OBJECT, throwable));
       Tags.HTTP_STATUS.set(span, 500);
       span.finish(); // Finish the span manually since finishSpanOnClose was false
       throw throwable;
     }
-
+    DECORATE.onResponse(span, response);
-    Tags.HTTP_STATUS.set(span, response.status().code());
+    DECORATE.beforeFinish(span);
     span.finish(); // Finish the span manually since finishSpanOnClose was false
   }
 }

dd-java-agent/instrumentation/netty-4.1/src/main/java/datadog/trace/instrumentation/netty41/server/NettyHttpServerDecorator.java

@@ -0,0 +1,61 @@
+package datadog.trace.instrumentation.netty41.server;
+
+import static io.netty.handler.codec.http.HttpHeaders.Names.HOST;
+
+import datadog.trace.agent.decorator.HttpServerDecorator;
+import io.netty.handler.codec.http.HttpRequest;
+import io.netty.handler.codec.http.HttpResponse;
+import java.net.URI;
+import java.net.URISyntaxException;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class NettyHttpServerDecorator extends HttpServerDecorator<HttpRequest, HttpResponse> {
+  public static final NettyHttpServerDecorator DECORATE = new NettyHttpServerDecorator();
+
+  @Override
+  protected String[] instrumentationNames() {
+    return new String[] {"netty", "netty-4.0"};
+  }
+
+  @Override
+  protected String component() {
+    return "netty";
+  }
+
+  @Override
+  protected String method(final HttpRequest httpRequest) {
+    return httpRequest.method().name();
+  }
+
+  @Override
+  protected String url(final HttpRequest request) {
+    // FIXME: This code is duplicated across netty integrations.
+    try {
+      URI uri = new URI(request.uri());
+      if ((uri.getHost() == null || uri.getHost().equals("")) && request.headers().contains(HOST)) {
+        uri = new URI("http://" + request.headers().get(HOST) + request.uri());
+      }
+      return new URI(uri.getScheme(), null, uri.getHost(), uri.getPort(), uri.getPath(), null, null)
+          .toString();
+    } catch (final URISyntaxException e) {
+      log.debug("Cannot parse netty uri: {}", request.uri());
+      return request.uri();
+    }
+  }
+
+  @Override
+  protected String hostname(final HttpRequest httpRequest) {
+    return null;
+  }
+
+  @Override
+  protected Integer port(final HttpRequest httpRequest) {
+    return null;
+  }
+
+  @Override
+  protected Integer status(final HttpResponse httpResponse) {
+    return httpResponse.status().code();
+  }
+}

dd-java-agent/instrumentation/netty-4.1/src/test/groovy/Netty41ClientTest.groovy

@@ -58,7 +58,8 @@ class Netty41ClientTest extends AgentTestRunner {
             "$Tags.HTTP_STATUS.key" 200
             "$Tags.HTTP_URL.key" "$server.address/"
             "$Tags.PEER_HOSTNAME.key" "localhost"
-            "$Tags.PEER_PORT.key" Integer
+            "$Tags.PEER_HOST_IPV4.key" "127.0.0.1"
+            "$Tags.PEER_PORT.key" server.address.port
             "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_CLIENT
             defaultTags()
           }

dd-java-agent/instrumentation/netty-4.1/src/test/groovy/Netty41ServerTest.groovy

@@ -13,7 +13,6 @@ import io.netty.channel.nio.NioEventLoopGroup
 import io.netty.channel.socket.nio.NioServerSocketChannel
 import io.netty.handler.codec.http.DefaultFullHttpResponse
 import io.netty.handler.codec.http.FullHttpResponse
-import io.netty.handler.codec.http.HttpHeaderNames
 import io.netty.handler.codec.http.HttpRequestDecoder
 import io.netty.handler.codec.http.HttpResponseEncoder
 import io.netty.handler.codec.http.HttpResponseStatus
@@ -28,6 +27,9 @@ import okhttp3.OkHttpClient
 import okhttp3.Request
 import spock.lang.Shared
 
+import static io.netty.handler.codec.http.HttpHeaderNames.CONTENT_LENGTH
+import static io.netty.handler.codec.http.HttpHeaderNames.CONTENT_TYPE
+
 class Netty41ServerTest extends AgentTestRunner {
 
   @Shared
@@ -68,6 +70,7 @@ class Netty41ServerTest extends AgentTestRunner {
             "$Tags.HTTP_STATUS.key" 200
             "$Tags.HTTP_URL.key" "http://localhost:$port/"
             "$Tags.PEER_HOSTNAME.key" "localhost"
+            "$Tags.PEER_HOST_IPV4.key" "127.0.0.1"
             "$Tags.PEER_PORT.key" Integer
             "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             defaultTags(true)
@@ -113,6 +116,7 @@ class Netty41ServerTest extends AgentTestRunner {
             "$Tags.HTTP_STATUS.key" responseCode.code()
             "$Tags.HTTP_URL.key" "http://localhost:$port/"
             "$Tags.PEER_HOSTNAME.key" "localhost"
+            "$Tags.PEER_HOST_IPV4.key" "127.0.0.1"
             "$Tags.PEER_PORT.key" Integer
             "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             if (error) {
@@ -147,8 +151,8 @@ class Netty41ServerTest extends AgentTestRunner {
             if (msg instanceof LastHttpContent) {
               ByteBuf content = Unpooled.copiedBuffer("Hello World", CharsetUtil.UTF_8)
               FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, responseCode, content)
-              response.headers().set(HttpHeaderNames.CONTENT_TYPE, "text/plain")
+              response.headers().set(CONTENT_TYPE, "text/plain")
-              response.headers().set(HttpHeaderNames.CONTENT_LENGTH, content.readableBytes())
+              response.headers().set(CONTENT_LENGTH, content.readableBytes())
               ctx.write(response)
             }
           },

dd-java-agent/instrumentation/spring-webflux/src/test/groovy/SpringWebfluxTest.groovy

@@ -84,6 +84,7 @@ class SpringWebfluxTest extends AgentTestRunner {
             "$Tags.COMPONENT.key" "netty"
             "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             "$Tags.PEER_HOSTNAME.key" "localhost"
+            "$Tags.PEER_HOST_IPV4.key" "127.0.0.1"
             "$Tags.PEER_PORT.key" Integer
             "$Tags.HTTP_METHOD.key" "GET"
             "$Tags.HTTP_STATUS.key" 200
@@ -156,6 +157,7 @@ class SpringWebfluxTest extends AgentTestRunner {
             "$Tags.COMPONENT.key" "netty"
             "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             "$Tags.PEER_HOSTNAME.key" "localhost"
+            "$Tags.PEER_HOST_IPV4.key" "127.0.0.1"
             "$Tags.PEER_PORT.key" Integer
             "$Tags.HTTP_METHOD.key" "GET"
             "$Tags.HTTP_STATUS.key" 200
@@ -216,6 +218,7 @@ class SpringWebfluxTest extends AgentTestRunner {
             "$Tags.COMPONENT.key" "netty"
             "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             "$Tags.PEER_HOSTNAME.key" "localhost"
+            "$Tags.PEER_HOST_IPV4.key" "127.0.0.1"
             "$Tags.PEER_PORT.key" Integer
             "$Tags.HTTP_METHOD.key" "GET"
             "$Tags.HTTP_STATUS.key" 404
@@ -278,6 +281,7 @@ class SpringWebfluxTest extends AgentTestRunner {
             "$Tags.COMPONENT.key" "netty"
             "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             "$Tags.PEER_HOSTNAME.key" "localhost"
+            "$Tags.PEER_HOST_IPV4.key" "127.0.0.1"
             "$Tags.PEER_PORT.key" Integer
             "$Tags.HTTP_METHOD.key" "POST"
             "$Tags.HTTP_STATUS.key" 202
@@ -320,6 +324,7 @@ class SpringWebfluxTest extends AgentTestRunner {
             "$Tags.COMPONENT.key" "netty"
             "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             "$Tags.PEER_HOSTNAME.key" "localhost"
+            "$Tags.PEER_HOST_IPV4.key" "127.0.0.1"
             "$Tags.PEER_PORT.key" Integer
             "$Tags.HTTP_METHOD.key" "GET"
             "$Tags.HTTP_STATUS.key" 500
@@ -392,6 +397,7 @@ class SpringWebfluxTest extends AgentTestRunner {
             "$Tags.COMPONENT.key" "netty"
             "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             "$Tags.PEER_HOSTNAME.key" "localhost"
+            "$Tags.PEER_HOST_IPV4.key" "127.0.0.1"
             "$Tags.PEER_PORT.key" Integer
             "$Tags.HTTP_METHOD.key" "GET"
             "$Tags.HTTP_STATUS.key" 307
@@ -439,6 +445,7 @@ class SpringWebfluxTest extends AgentTestRunner {
             "$Tags.COMPONENT.key" "netty"
             "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             "$Tags.PEER_HOSTNAME.key" "localhost"
+            "$Tags.PEER_HOST_IPV4.key" "127.0.0.1"
             "$Tags.PEER_PORT.key" Integer
             "$Tags.HTTP_METHOD.key" "GET"
             "$Tags.HTTP_STATUS.key" 200
@@ -500,6 +507,7 @@ class SpringWebfluxTest extends AgentTestRunner {
               "$Tags.COMPONENT.key" "netty"
               "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
               "$Tags.PEER_HOSTNAME.key" "localhost"
+              "$Tags.PEER_HOST_IPV4.key" "127.0.0.1"
               "$Tags.PEER_PORT.key" Integer
               "$Tags.HTTP_METHOD.key" "GET"
               "$Tags.HTTP_STATUS.key" 200

dd-java-agent/instrumentation/vertx/src/test/groovy/VertxHttpClientTest.groovy

@@ -80,6 +80,7 @@ class VertxHttpClientTest extends AgentTestRunner {
             "$Tags.HTTP_STATUS.key" expectedStatus
             "$Tags.HTTP_URL.key" "${server.address}/$route"
             "$Tags.PEER_HOSTNAME.key" server.address.host
+            "$Tags.PEER_HOST_IPV4.key" "127.0.0.1"
             "$Tags.PEER_PORT.key" server.address.port
             "$Tags.HTTP_METHOD.key" "GET"
             "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_CLIENT

dd-java-agent/instrumentation/vertx/src/test/groovy/VertxServerTest.groovy

@@ -59,6 +59,7 @@ class VertxServerTest extends AgentTestRunner {
             "$Tags.HTTP_STATUS.key" 200
             "$Tags.HTTP_URL.key" "http://localhost:$port/test"
             "$Tags.PEER_HOSTNAME.key" "localhost"
+            "$Tags.PEER_HOST_IPV4.key" "127.0.0.1"
             "$Tags.PEER_PORT.key" Integer
             "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             defaultTags(true)
@@ -95,6 +96,7 @@ class VertxServerTest extends AgentTestRunner {
             "$Tags.HTTP_STATUS.key" responseCode.code()
             "$Tags.HTTP_URL.key" "http://localhost:$port/$path"
             "$Tags.PEER_HOSTNAME.key" "localhost"
+            "$Tags.PEER_HOST_IPV4.key" "127.0.0.1"
             "$Tags.PEER_PORT.key" Integer
             "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             if (error) {