add: instrumentation for apache http client 4.x (#1330)

@PrajeenRG LGTM! Sorry about the delay getting back to you there. Merging 🚀

build.sbt

@@ -147,7 +147,8 @@ val instrumentationProjects = Seq[ProjectReference](
   `kamon-aws-sdk`,
   `kamon-alpakka-kafka`,
   `kamon-http4s-1_0`,
-  `kamon-http4s-0_23`
+  `kamon-http4s-0_23`,
+  `kamon-apache-httpclient`
 )
 
 lazy val instrumentation = (project in file("instrumentation"))
@@ -820,6 +821,25 @@ lazy val `kamon-http4s-0_23` = (project in file("instrumentation/kamon-http4s-0.
     `kamon-testkit` % Test
   )
 
+lazy val `kamon-apache-httpclient` = (project in file("instrumentation/kamon-apache-httpclient"))
+  .disablePlugins(AssemblyPlugin)
+  .enablePlugins(JavaAgent)
+  .settings(instrumentationSettings)
+  .settings(
+    libraryDependencies ++= Seq(
+      kanelaAgent % "provided",
+      "org.apache.httpcomponents" % "httpclient" % "4.0" % "provided",
+      slf4jApi % "provided",
+
+      scalatest % "test",
+      logbackClassic % "test",
+      "org.mock-server" % "mockserver-client-java" % "5.13.2" % "test",
+      "com.dimafeng" %% "testcontainers-scala" % "0.41.0" % "test",
+      "com.dimafeng" %% "testcontainers-scala-mockserver" % "0.41.0" % "test"
+    )
+  ).dependsOn(`kamon-core`, `kamon-executors`, `kamon-testkit` % "test")
+
+
 /**
  * Reporters
  */
@@ -1087,7 +1107,8 @@ lazy val `kamon-bundle-dependencies-all` = (project in file("bundle/kamon-bundle
     `kamon-okhttp`,
     `kamon-caffeine`,
     `kamon-lagom`,
-    `kamon-aws-sdk`
+    `kamon-aws-sdk`,
+    `kamon-apache-httpclient`
   )
 
 /**
@@ -1151,7 +1172,8 @@ lazy val `kamon-bundle-dependencies-3` = (project in file("bundle/kamon-bundle-d
     `kamon-zio-2`,
     `kamon-pekko`,
     `kamon-pekko-http`,
-    `kamon-pekko-grpc`
+    `kamon-pekko-grpc`,
+    `kamon-apache-httpclient`
   )
 
 lazy val `kamon-bundle` = (project in file("bundle/kamon-bundle"))

instrumentation/kamon-apache-httpclient/src/main/java/kamon/instrumentation/apache/httpclient/RequestAdvisor.java

@@ -0,0 +1,48 @@
+package kamon.instrumentation.apache.httpclient;
+
+import org.apache.http.HttpHost;
+import org.apache.http.HttpRequest;
+import org.apache.http.HttpResponse;
+
+import kamon.instrumentation.http.HttpClientInstrumentation.RequestHandler;
+import kamon.instrumentation.http.HttpMessage.RequestBuilder;
+import kamon.trace.Span;
+import kamon.Kamon;
+import kamon.context.Context;
+import kamon.context.Storage.Scope;
+import kamon.instrumentation.context.HasContext;
+
+import kanela.agent.libs.net.bytebuddy.asm.Advice;
+
+public class RequestAdvisor {
+
+    @Advice.OnMethodEnter(suppress = Throwable.class)
+    public static void onEnter(@Advice.Argument(0) HttpHost host,
+            @Advice.Argument(value = 1, readOnly = false) HttpRequest request,
+            @Advice.Local("handler") RequestHandler<HttpRequest> handler,
+            @Advice.Local("scope") Scope scope) {
+        if (((HasContext) request).context().nonEmpty()) {
+            // Request has been instrumented already
+            return;
+        }
+        final Context parentContext = Kamon.currentContext();
+        final RequestBuilder<HttpRequest> builder = ApacheHttpClientHelper.toRequestBuilder(host, request);
+        handler = ApacheHttpClientInstrumentation.httpClientInstrumentation().createHandler(builder, parentContext);
+        final Context ctx = parentContext.withEntry(Span.Key(), handler.span());
+        scope = Kamon.storeContext(ctx);
+        request = handler.request();
+        ((HasContext) request).setContext(ctx);
+    }
+
+    @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)
+    public static void onExit(@Advice.Return HttpResponse response,
+            @Advice.Thrown Throwable t,
+            @Advice.Local("handler") RequestHandler<HttpRequest> handler,
+            @Advice.Local("scope") Scope scope) {
+        if (scope == null) {
+            return;
+        }
+        ApacheHttpClientInstrumentation.processResponse(handler, response, t);
+        scope.close();
+    }
+}

instrumentation/kamon-apache-httpclient/src/main/java/kamon/instrumentation/apache/httpclient/RequestWithHandlerAdvisor.java

@@ -0,0 +1,44 @@
+package kamon.instrumentation.apache.httpclient;
+
+import org.apache.http.HttpHost;
+import org.apache.http.HttpRequest;
+import org.apache.http.client.ResponseHandler;
+
+import kamon.Kamon;
+import kamon.context.Context;
+import kamon.context.Storage.Scope;
+import kamon.instrumentation.context.HasContext;
+import kamon.instrumentation.http.HttpClientInstrumentation.RequestHandler;
+import kamon.instrumentation.http.HttpMessage.RequestBuilder;
+import kamon.trace.Span;
+import kanela.agent.libs.net.bytebuddy.asm.Advice;
+
+public class RequestWithHandlerAdvisor {
+
+    @Advice.OnMethodEnter(suppress = Throwable.class)
+    public static void onEnter(@Advice.Argument(0) HttpHost host,
+            @Advice.Argument(value = 1, readOnly = false) HttpRequest request,
+            @Advice.Argument(value = 2, readOnly = false) ResponseHandler<?> resHandler,
+            @Advice.Local("handler") RequestHandler<HttpRequest> reqHandler,
+            @Advice.Local("scope") Scope scope) {
+        if (((HasContext) request).context().nonEmpty()) {
+            // Request has been instrumented already
+            return;
+        }
+        final Context parentContext = Kamon.currentContext();
+        final RequestBuilder<HttpRequest> builder = ApacheHttpClientHelper.toRequestBuilder(host, request);
+        reqHandler = ApacheHttpClientInstrumentation.httpClientInstrumentation().createHandler(builder, parentContext);
+        resHandler = new ResponseHandlerProxy<>(reqHandler, resHandler, parentContext);
+        final Context ctx = parentContext.withEntry(Span.Key(), reqHandler.span());
+        scope = Kamon.storeContext(ctx);
+        request = reqHandler.request();
+        ((HasContext) request).setContext(ctx);
+    }
+
+    @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)
+    public static void onExit(@Advice.Local("scope") Scope scope) {
+        if (scope != null) {
+            scope.close();
+        }
+    }
+}

instrumentation/kamon-apache-httpclient/src/main/java/kamon/instrumentation/apache/httpclient/ResponseHandlerProxy.java

@@ -0,0 +1,35 @@
+package kamon.instrumentation.apache.httpclient;
+
+import java.io.IOException;
+
+import org.apache.http.HttpResponse;
+import org.apache.http.client.ClientProtocolException;
+import org.apache.http.client.ResponseHandler;
+
+import kamon.Kamon;
+import kamon.context.Context;
+import kamon.context.Storage.Scope;
+import kamon.instrumentation.http.HttpClientInstrumentation.RequestHandler;
+
+public class ResponseHandlerProxy<T, U> implements ResponseHandler<T> {
+
+    private final ResponseHandler<T> delegate;
+    private final RequestHandler<U> handler;
+    private Context parentContext;
+
+    public ResponseHandlerProxy(RequestHandler<U> handler, ResponseHandler<T> delegate, Context parentContext) {
+        this.handler = handler;
+        this.delegate = delegate;
+        this.parentContext = parentContext;
+    }
+
+    @Override
+    public T handleResponse(HttpResponse response) throws ClientProtocolException, IOException {
+        ApacheHttpClientInstrumentation.processResponse(handler, response, null);
+        // run original handler in parent context to avoid nesting of spans
+        try (Scope ignored = Kamon.storeContext(parentContext)) {
+            return delegate.handleResponse(response);
+        }
+    }
+
+}

instrumentation/kamon-apache-httpclient/src/main/java/kamon/instrumentation/apache/httpclient/UriRequestAdvisor.java

@@ -0,0 +1,45 @@
+package kamon.instrumentation.apache.httpclient;
+
+import org.apache.http.HttpResponse;
+import org.apache.http.client.methods.HttpUriRequest;
+
+import kamon.Kamon;
+import kamon.context.Context;
+import kamon.context.Storage.Scope;
+import kamon.instrumentation.context.HasContext;
+import kamon.instrumentation.http.HttpClientInstrumentation.RequestHandler;
+import kamon.instrumentation.http.HttpMessage.RequestBuilder;
+import kamon.trace.Span;
+import kanela.agent.libs.net.bytebuddy.asm.Advice;
+
+public class UriRequestAdvisor {
+
+    @Advice.OnMethodEnter(suppress = Throwable.class)
+    public static void onEnter(@Advice.Argument(value = 0, readOnly = false) HttpUriRequest request,
+            @Advice.Local("handler") RequestHandler<HttpUriRequest> handler,
+            @Advice.Local("scope") Scope scope) {
+        if (((HasContext) request).context().nonEmpty()) {
+            // Request has been instrumented already
+            return;
+        }
+        final Context parentContext = Kamon.currentContext();
+        final RequestBuilder<HttpUriRequest> builder = ApacheHttpClientHelper.toRequestBuilder(request);
+        handler = ApacheHttpClientInstrumentation.httpClientInstrumentation().createHandler(builder, parentContext);
+        final Context ctx = parentContext.withEntry(Span.Key(), handler.span());
+        scope = Kamon.storeContext(ctx);
+        request = handler.request();
+        ((HasContext) request).setContext(ctx);
+    }
+
+    @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)
+    public static void onExit(@Advice.Return HttpResponse response,
+            @Advice.Thrown Throwable t,
+            @Advice.Local("handler") RequestHandler<HttpUriRequest> handler,
+            @Advice.Local("scope") Scope scope) {
+        if (scope == null) {
+            return;
+        }
+        ApacheHttpClientInstrumentation.processResponse(handler, response, t);
+        scope.close();
+    }
+}

instrumentation/kamon-apache-httpclient/src/main/java/kamon/instrumentation/apache/httpclient/UriRequestWithHandlerAdvisor.java

@@ -0,0 +1,43 @@
+package kamon.instrumentation.apache.httpclient;
+
+import org.apache.http.client.ResponseHandler;
+import org.apache.http.client.methods.HttpUriRequest;
+
+import kamon.Kamon;
+import kamon.context.Context;
+import kamon.context.Storage.Scope;
+import kamon.instrumentation.context.HasContext;
+import kamon.instrumentation.http.HttpClientInstrumentation.RequestHandler;
+import kamon.instrumentation.http.HttpMessage.RequestBuilder;
+import kamon.trace.Span;
+import kanela.agent.libs.net.bytebuddy.asm.Advice;
+
+public class UriRequestWithHandlerAdvisor {
+
+    @Advice.OnMethodEnter(suppress = Throwable.class)
+    public static void onEnter(
+            @Advice.Argument(value = 0, readOnly = false) HttpUriRequest request,
+            @Advice.Argument(value = 1, readOnly = false) ResponseHandler<?> resHandler,
+            @Advice.Local("handler") RequestHandler<HttpUriRequest> reqHandler,
+            @Advice.Local("scope") Scope scope) {
+        if (((HasContext) request).context().nonEmpty()) {
+            // Request has been instrumented already
+            return;
+        }
+        final Context parentContext = Kamon.currentContext();
+        final RequestBuilder<HttpUriRequest> builder = ApacheHttpClientHelper.toRequestBuilder(request);
+        reqHandler = ApacheHttpClientInstrumentation.httpClientInstrumentation().createHandler(builder, parentContext);
+        resHandler = new ResponseHandlerProxy<>(reqHandler, resHandler, parentContext);
+        final Context ctx = parentContext.withEntry(Span.Key(), reqHandler.span());
+        scope = Kamon.storeContext(ctx);
+        request = reqHandler.request();
+        ((HasContext) request).setContext(ctx);
+    }
+
+    @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)
+    public static void onExit(@Advice.Local("scope") Scope scope) {
+        if (scope != null) {
+            scope.close();
+        }
+    }
+}

instrumentation/kamon-apache-httpclient/src/main/resources/reference.conf

@@ -0,0 +1,99 @@
+# ================================================== #
+# kamon Apache HttpClient 2.0 client reference configuration #
+# ================================================== #
+
+# Settings to control the HTTP Client instrumentation
+#
+# IMPORTANT: The entire configuration of the HTTP Client Instrumentation is based on the constructs provided by the
+# Kamon Instrumentation Common library which will always fallback to the settings found under the
+# "kamon.instrumentation.http-client.default" path. The default settings have been included here to make them easy to
+# find and understand in the context of this project and commented out so that any changes to the default settings
+# will actually have effect.
+#
+kamon.instrumentation.apache.httpclient {
+
+  #
+  # Configuration for HTTP context propagation.
+  #
+  propagation {
+
+    # Enables or disables HTTP context propagation on this HTTP client instrumentation. Please note that if
+    # propagation is disabled then some distributed tracing features will not be work as expected (e.g. Spans can
+    # be created and reported but will not be linked across boundaries nor take trace identifiers from tags).
+    #enabled = yes
+
+    # HTTP propagation channel to b used by this instrumentation. Take a look at the kamon.propagation.http.default
+    # configuration for more details on how to configure the detault HTTP context propagation.
+    #channel = "default"
+  }
+
+  tracing {
+
+    # Enables HTTP request tracing. When enabled the instrumentation will create Spans for outgoing requests
+    # and finish them when the response is received from the server.
+    #enabled = yes
+
+    # Enables collection of span metrics using the `span.processing-time` metric.
+    #span-metrics = on
+
+    # Select which tags should be included as span and span metric tags. The possible options are:
+    #   - span: the tag is added as a Span tag (i.e. using span.tag(...))
+    #   - metric: the tag is added a a Span metric tag (i.e. using span.tagMetric(...))
+    #   - off: the tag is not used.
+    #
+    tags {
+
+      # Use the http.url tag.
+      #url = span
+
+      # Use the http.method tag.
+      #method = metric
+
+      # Use the http.status_code tag.
+      #status-code = metric
+
+      # Copy tags from the context into the Spans with the specified purpouse. For example, to copy a customer_type
+      # tag from the context into the HTTP Client Span created by the instrumentation, the following configuration
+      # should be added:
+      #
+      # from-context {
+      #   customer_type = span
+      # }
+      #
+      from-context {
+
+      }
+    }
+
+    operations {
+
+      # The default operation name to be used when creating Spans to handle the HTTP client requests. The HTTP
+      # Client instrumentation will always try to use the HTTP Operation Name Generator configured below to get
+      # a name, but if it fails to generate it then this name will be used.
+      #default = "http.client.request"
+
+      # FQCN for a HttpOperationNameGenerator implementation, or ony of the following shorthand forms:
+      #   - hostname: Uses the request Host as the operation name.
+      #   - method: Uses the request HTTP method as the operation name.
+      #
+      #name-generator = "method"
+    }
+  }
+
+}
+
+kanela {
+  modules {
+    apache-httpclient {
+      name = "Apache Http Client"
+      description = "Provides tracing of client calls made with the official Apache HttpClient library."
+      instrumentations = [
+        "kamon.instrumentation.apache.httpclient.ApacheHttpClientInstrumentation"
+      ]
+
+      within = [
+        "org.apache.http..*"
+      ]
+    }
+  }
+}