feat: Micrometer Observation instrumentation

flow-server/pom.xml

@@ -135,6 +135,20 @@
             <artifactId>commons-compress</artifactId>
             <version>1.23.0</version>
         </dependency>
+
+        <dependency>
+            <groupId>io.micrometer</groupId>
+            <artifactId>micrometer-observation</artifactId>
+            <version>${micrometer.version}</version>
+            <optional>true</optional>
+        </dependency>
+        <dependency>
+            <groupId>io.micrometer</groupId>
+            <artifactId>micrometer-jakarta</artifactId>
+            <version>${micrometer.version}</version>
+            <optional>true</optional>
+        </dependency>
+
         <!-- TESTING DEPENDENCIES -->
         <dependency>
             <groupId>com.vaadin</groupId>

flow-server/src/main/java/com/vaadin/flow/server/ObservedVaadinFilter.java

@@ -0,0 +1,65 @@
+package com.vaadin.flow.server;
+
+import io.micrometer.common.lang.Nullable;
+import io.micrometer.jakarta.instrument.binder.http.DefaultHttpJakartaServerServletRequestObservationConvention;
+import io.micrometer.jakarta.instrument.binder.http.HttpJakartaServerServletRequestObservationContext;
+import io.micrometer.jakarta.instrument.binder.http.HttpJakartaServerServletRequestObservationConvention;
+import io.micrometer.jakarta.instrument.binder.http.JakartaHttpObservationDocumentation;
+import io.micrometer.observation.Observation;
+import io.micrometer.observation.ObservationRegistry;
+import jakarta.servlet.http.HttpServletResponse;
+
+/**
+ * Micrometer Observation {@link VaadinFilter} that will start
+ * observations around processing of a request.
+ *
+ * @author Marcin Grzejszczak
+ * @since 24.2
+ */
+public class ObservedVaadinFilter implements VaadinFilter {
+
+    private static final String SCOPE_ATTRIBUTE = ObservedVaadinFilter.class.getName() + ".scope";
+
+    private final ObservationRegistry observationRegistry;
+
+    private final HttpJakartaServerServletRequestObservationConvention convention;
+
+    public ObservedVaadinFilter(ObservationRegistry observationRegistry,
+                                @Nullable HttpJakartaServerServletRequestObservationConvention convention) {
+        this.observationRegistry = observationRegistry;
+        this.convention = convention;
+    }
+
+    @Override
+    public void requestStart(VaadinRequest request, VaadinResponse response) {
+        if (request instanceof VaadinServletRequest servletRequest && response instanceof VaadinServletResponse servletResponse) {
+            HttpJakartaServerServletRequestObservationContext context = new HttpJakartaServerServletRequestObservationContext(servletRequest, servletResponse);
+            Observation observation = JakartaHttpObservationDocumentation.JAKARTA_SERVLET_SERVER_OBSERVATION.start(this.convention, DefaultHttpJakartaServerServletRequestObservationConvention.INSTANCE, () -> context, observationRegistry);
+            request.setAttribute(SCOPE_ATTRIBUTE, observation.openScope());
+        }
+    }
+
+    @Override
+    public void handleException(VaadinRequest request, VaadinResponse response, VaadinSession vaadinSession, Exception t) {
+        Observation.Scope scope = (Observation.Scope) request.getAttribute(SCOPE_ATTRIBUTE);
+        if (scope == null) {
+            return;
+        }
+        scope.getCurrentObservation().error(t);
+    }
+
+    @Override
+    public void requestEnd(VaadinRequest request, VaadinResponse response, VaadinSession session) {
+        Observation.Scope scope = (Observation.Scope) request.getAttribute(SCOPE_ATTRIBUTE);
+        if (scope == null) {
+            return;
+        }
+        scope.close();
+        Observation observation = scope.getCurrentObservation();
+        if (!observation.isNoop() && response instanceof HttpServletResponse httpServletResponse) {
+            HttpJakartaServerServletRequestObservationContext ctx = (HttpJakartaServerServletRequestObservationContext) observation.getContext();
+            ctx.setResponse(httpServletResponse);
+        }
+        observation.stop();
+    }
+}

flow-server/src/main/java/com/vaadin/flow/server/VaadinFilter.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2000-2023 Vaadin Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+package com.vaadin.flow.server;
+
+import java.io.Serializable;
+
+/**
+ * Used to provide an around-like aspect option around request processing.
+ *
+ * @author Marcin Grzejszczak
+ * @since 24.2
+ */
+public interface VaadinFilter extends Serializable {
+
+    /**
+     * Called when request is about to be processed.
+     * @param request request
+     * @param response response
+     */
+    void requestStart(VaadinRequest request, VaadinResponse response);
+
+    /**
+     * Called when an exception occurred
+     * @param request request
+     * @param response response
+     * @param vaadinSession session
+     * @param t exception
+     */
+    void handleException(VaadinRequest request,
+                         VaadinResponse response, VaadinSession vaadinSession, Exception t);
+
+    /**
+     * Called in the finally block of processing a request. Will be called
+     * regardless of whether there was an exception or not.
+     * @param request request
+     * @param response response
+     * @param session session
+     */
+    void requestEnd(VaadinRequest request, VaadinResponse response,
+                    VaadinSession session);
+}

flow-server/src/main/java/com/vaadin/flow/server/VaadinService.java

@@ -16,41 +16,6 @@
 
 package com.vaadin.flow.server;
 
-import java.io.BufferedWriter;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
-import java.io.OutputStreamWriter;
-import java.io.PrintWriter;
-import java.io.Serializable;
-import java.lang.reflect.Constructor;
-import java.net.URL;
-import java.nio.charset.StandardCharsets;
-import java.security.MessageDigest;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Locale;
-import java.util.Map;
-import java.util.Map.Entry;
-import java.util.Optional;
-import java.util.ServiceLoader;
-import java.util.Set;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.CopyOnWriteArrayList;
-import java.util.concurrent.Future;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.locks.Lock;
-import java.util.concurrent.locks.ReentrantLock;
-import java.util.stream.Collectors;
-import java.util.stream.StreamSupport;
-
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import com.vaadin.flow.component.UI;
 import com.vaadin.flow.di.DefaultInstantiator;
 import com.vaadin.flow.di.Instantiator;
@@ -64,26 +29,30 @@
 import com.vaadin.flow.router.RouteData;
 import com.vaadin.flow.router.Router;
 import com.vaadin.flow.server.HandlerHelper.RequestType;
-import com.vaadin.flow.server.communication.AtmospherePushConnection;
-import com.vaadin.flow.server.communication.HeartbeatHandler;
-import com.vaadin.flow.server.communication.IndexHtmlRequestListener;
-import com.vaadin.flow.server.communication.IndexHtmlResponse;
-import com.vaadin.flow.server.communication.JavaScriptBootstrapHandler;
-import com.vaadin.flow.server.communication.PwaHandler;
-import com.vaadin.flow.server.communication.SessionRequestHandler;
-import com.vaadin.flow.server.communication.StreamRequestHandler;
-import com.vaadin.flow.server.communication.UidlRequestHandler;
-import com.vaadin.flow.server.communication.WebComponentBootstrapHandler;
-import com.vaadin.flow.server.communication.WebComponentProvider;
+import com.vaadin.flow.server.communication.*;
 import com.vaadin.flow.shared.ApplicationConstants;
 import com.vaadin.flow.shared.JsonConstants;
 import com.vaadin.flow.shared.Registration;
 import com.vaadin.flow.shared.communication.PushMode;
-
 import elemental.json.Json;
 import elemental.json.JsonException;
 import elemental.json.JsonObject;
 import elemental.json.impl.JsonUtil;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.*;
+import java.lang.reflect.Constructor;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.security.MessageDigest;
+import java.util.*;
+import java.util.Map.Entry;
+import java.util.concurrent.*;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.stream.Collectors;
+import java.util.stream.StreamSupport;
 
 import static java.nio.charset.StandardCharsets.UTF_8;
 
@@ -114,6 +83,8 @@ public abstract class VaadinService implements Serializable {
             + PushMode.class.getSimpleName() + "." + PushMode.DISABLED.name()
             + "." + SEPARATOR;
 
+    private List<VaadinFilter> vaadinFilters = new ArrayList<>();
+
     /**
      * Attribute name for telling
      * {@link VaadinSession#valueUnbound(jakarta.servlet.http.HttpSessionBindingEvent)}
@@ -1433,6 +1404,7 @@ public void requestStart(VaadinRequest request, VaadinResponse response) {
         }
         setCurrentInstances(request, response);
         request.setAttribute(REQUEST_START_TIME_ATTRIBUTE, System.nanoTime());
+        vaadinFilters.forEach(vaadinFilter -> vaadinFilter.requestStart(request, response));
     }
 
     /**
@@ -1449,6 +1421,7 @@ public void requestStart(VaadinRequest request, VaadinResponse response) {
      */
     public void requestEnd(VaadinRequest request, VaadinResponse response,
             VaadinSession session) {
+        vaadinFilters.forEach(vaadinFilter -> vaadinFilter.requestEnd(request, response, session));
         if (session != null) {
             assert VaadinSession.getCurrent() == session;
             session.lock();
@@ -1544,6 +1517,15 @@ private void handleExceptionDuringRequest(VaadinRequest request,
             vaadinSession.lock();
         }
         try {
+            try {
+                vaadinFilters.forEach(vaadinFilter -> vaadinFilter.handleException(request,
+                        response, vaadinSession, t));
+            } catch (Exception ex) {
+                // An exception occurred while handling an exception. Log
+                // it and continue handling only the original error.
+                getLogger().warn(
+                        "Failed to handle an exception using filters", ex);
+            }
             if (vaadinSession != null) {
                 vaadinSession.getErrorHandler().error(new ErrorEvent(t));
             }
@@ -2374,6 +2356,14 @@ public static String getCsrfTokenAttributeName() {
                 + ApplicationConstants.CSRF_TOKEN;
     }
 
+    public List<VaadinFilter> getVaadinFilters() {
+        return vaadinFilters;
+    }
+
+    public void setVaadinFilters(List<VaadinFilter> vaadinFilters) {
+        this.vaadinFilters = vaadinFilters;
+    }
+
     private void doSetClassLoader() {
         final String classLoaderName = getDeploymentConfiguration() == null
                 ? null
@@ -2398,4 +2388,4 @@ private void doSetClassLoader() {
             setDefaultClassLoader();
         }
     }
-}
+}

flow-server/src/main/java/com/vaadin/flow/server/VaadinServlet.java

@@ -15,19 +15,6 @@
  */
 package com.vaadin.flow.server;
 
-import java.io.IOException;
-import java.net.MalformedURLException;
-import java.net.URL;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
-import java.util.Properties;
-
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import com.vaadin.flow.component.UI;
 import com.vaadin.flow.di.Lookup;
 import com.vaadin.flow.function.DeploymentConfiguration;
@@ -37,14 +24,20 @@
 import com.vaadin.flow.server.HandlerHelper.RequestType;
 import com.vaadin.flow.server.startup.ApplicationConfiguration;
 import com.vaadin.flow.shared.JsonConstants;
-
 import jakarta.servlet.ServletConfig;
 import jakarta.servlet.ServletContext;
 import jakarta.servlet.ServletException;
 import jakarta.servlet.ServletRegistration;
 import jakarta.servlet.http.HttpServlet;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.*;
 
 /**
  * The main servlet, which handles all incoming requests to the application.
@@ -72,6 +65,8 @@ public class VaadinServlet extends HttpServlet {
 
     private static List<Runnable> whenFrontendMappingAvailable = new ArrayList<>();
 
+    private List<VaadinFilter> vaadinFilters = new ArrayList<>();
+
     /**
      * Called by the servlet container to indicate to a servlet that the servlet
      * is being placed into service.
@@ -589,9 +584,9 @@ static URL getApplicationUrl(HttpServletRequest request)
         final URL reqURL = new URL((request.isSecure() ? "https://" : "http://")
                 + request.getServerName()
                 + ((request.isSecure() && request.getServerPort() == 443)
-                        || (!request.isSecure()
-                                && request.getServerPort() == 80) ? ""
-                                        : ":" + request.getServerPort())
+                || (!request.isSecure()
+                && request.getServerPort() == 80) ? ""
+                : ":" + request.getServerPort())
                 + request.getRequestURI());
         String servletPath;
         if (request
@@ -601,7 +596,7 @@ static URL getApplicationUrl(HttpServletRequest request)
                     .getAttribute("jakarta.servlet.include.context_path")
                     .toString()
                     + request.getAttribute(
-                            "jakarta.servlet.include.servlet_path");
+                    "jakarta.servlet.include.servlet_path");
 
         } else {
             servletPath = request.getContextPath() + request.getServletPath();
@@ -647,6 +642,14 @@ private VaadinServletContext initializeContext() {
         return vaadinServletContext;
     }
 
+    public List<VaadinFilter> getVaadinFilters() {
+        return vaadinFilters;
+    }
+
+    public void setVaadinFilters(List<VaadinFilter> vaadinFilters) {
+        this.vaadinFilters = vaadinFilters;
+    }
+
     /**
      * For internal use only.
      *
@@ -656,4 +659,4 @@ public static String getFrontendMapping() {
         return frontendMapping;
     }
 
-}
+}