Fix [Broker Interceptor] Pulsar didn't respond error messages when hi…

…tting the resource limit (#17)

pulsar-broker/src/main/java/org/apache/pulsar/broker/web/ExceptionHandler.java

@@ -0,0 +1,57 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.pulsar.broker.web;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServletResponse;
+import javax.ws.rs.core.Response;
+import org.apache.pulsar.common.intercept.InterceptException;
+import org.eclipse.jetty.http.HttpVersion;
+import org.eclipse.jetty.http.MetaData;
+
+/**
+ *  Exception handler for handle exception.
+ */
+public class ExceptionHandler {
+
+    public void handle(ServletResponse response, Exception ex) throws IOException {
+        if (ex instanceof InterceptException) {
+            String reason = ex.getMessage();
+            byte[] content = reason.getBytes(StandardCharsets.UTF_8);
+            MetaData.Response info = new MetaData.Response();
+            info.setHttpVersion(HttpVersion.HTTP_1_1);
+            info.setReason(reason);
+            info.setStatus(((InterceptException) ex).getErrorCode());
+            info.setContentLength(content.length);
+            if (response instanceof org.eclipse.jetty.server.Response) {
+                ((org.eclipse.jetty.server.Response) response).getHttpChannel().sendResponse(info,
+                        ByteBuffer.wrap(content), true);
+            } else {
+                ((HttpServletResponse) response).sendError(((InterceptException) ex).getErrorCode(),
+                        ex.getMessage());
+            }
+        } else {
+            ((HttpServletResponse) response).sendError(Response.Status.INTERNAL_SERVER_ERROR.getStatusCode(),
+                    ex.getMessage());
+        }
+    }
+}

pulsar-broker/src/main/java/org/apache/pulsar/broker/web/PreInterceptFilter.java

@@ -26,7 +26,6 @@
 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServletRequest;
-import javax.servlet.http.HttpServletResponse;
 import javax.ws.rs.core.MediaType;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.commons.lang3.StringUtils;
@@ -38,8 +37,11 @@ public class PreInterceptFilter implements Filter {
 
     private final BrokerInterceptor interceptor;
 
-    public PreInterceptFilter(BrokerInterceptor interceptor) {
+    private final ExceptionHandler exceptionHandler;
+
+    public PreInterceptFilter(BrokerInterceptor interceptor, ExceptionHandler exceptionHandler) {
         this.interceptor = interceptor;
+        this.exceptionHandler = exceptionHandler;
     }
 
     @Override
@@ -67,7 +69,7 @@ public void doFilter(ServletRequest servletRequest, ServletResponse servletRespo
             interceptor.onWebserviceRequest(requestWrapper);
             filterChain.doFilter(requestWrapper, servletResponse);
         } catch (InterceptException e) {
-            ((HttpServletResponse) servletResponse).sendError(e.getErrorCode(), e.getMessage());
+            exceptionHandler.handle(servletResponse, e);
         }
     }
 

pulsar-broker/src/main/java/org/apache/pulsar/broker/web/WebService.java

@@ -159,11 +159,12 @@ public void addServlet(String path, ServletHolder servletHolder, boolean require
                 context.setAttribute(key, value);
             });
         }
+        ExceptionHandler handler = new ExceptionHandler();
 
         if (!pulsar.getConfig().getBrokerInterceptors().isEmpty()
                 || !pulsar.getConfig().isDisableBrokerInterceptors()) {
             // Enable PreInterceptFilter only when interceptors are enabled
-            context.addFilter(new FilterHolder(new PreInterceptFilter(pulsar.getBrokerInterceptor())),
+            context.addFilter(new FilterHolder(new PreInterceptFilter(pulsar.getBrokerInterceptor(), handler)),
                     MATCH_ALL, EnumSet.allOf(DispatcherType.class));
             context.addFilter(new FilterHolder(new ProcessHandlerFilter(pulsar)),
                     MATCH_ALL, EnumSet.allOf(DispatcherType.class));

pulsar-broker/src/test/java/org/apache/pulsar/broker/intercept/InterceptFilterOutTest.java

@@ -20,6 +20,7 @@
 
 import org.apache.pulsar.broker.PulsarService;
 import org.apache.pulsar.broker.ServiceConfiguration;
+import org.apache.pulsar.broker.web.ExceptionHandler;
 import org.apache.pulsar.broker.web.PreInterceptFilter;
 import org.apache.pulsar.broker.web.ProcessHandlerFilter;
 import org.apache.pulsar.broker.web.ResponseHandlerFilter;
@@ -61,7 +62,8 @@ public class InterceptFilterOutTest {
     @Test
     public void testFilterOutForPreInterceptFilter() throws Exception {
         CounterBrokerInterceptor interceptor = new CounterBrokerInterceptor();
-        PreInterceptFilter filter = new PreInterceptFilter(interceptor);
+        ExceptionHandler handler = new ExceptionHandler();
+        PreInterceptFilter filter = new PreInterceptFilter(interceptor, handler);
 
         HttpServletRequest request = Mockito.mock(HttpServletRequest.class);
         HttpServletResponse response = Mockito.mock(HttpServletResponse.class);

pulsar-broker/src/test/java/org/apache/pulsar/broker/web/ExceptionHandlerTest.java

@@ -0,0 +1,55 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.pulsar.broker.web;
+
+import lombok.SneakyThrows;
+import org.apache.pulsar.common.intercept.InterceptException;
+import org.eclipse.jetty.http.HttpStatus;
+import org.eclipse.jetty.server.HttpChannel;
+import org.eclipse.jetty.server.Response;
+import org.mockito.Mockito;
+import org.testng.annotations.Test;
+
+import javax.servlet.http.HttpServletResponse;
+
+/**
+ * Unit test for ExceptionHandler.
+ */
+@Test(groups = "broker")
+public class ExceptionHandlerTest {
+
+    @Test
+    @SneakyThrows
+    public void testHandle() {
+        ExceptionHandler handler = new ExceptionHandler();
+        HttpServletResponse response = Mockito.mock(HttpServletResponse.class);
+        handler.handle(response, new InterceptException(HttpStatus.PRECONDITION_FAILED_412, "Reach the max tenants [5] restriction"));
+        Mockito.verify(response).sendError(Mockito.anyInt(), Mockito.anyString());
+        handler.handle(response, new InterceptException(HttpStatus.INTERNAL_SERVER_ERROR_500, "internal exception"));
+        Mockito.verify(response, Mockito.times(2)).sendError(Mockito.anyInt(), Mockito.anyString());
+        handler.handle(response, new IllegalArgumentException("illegal argument exception "));
+        Mockito.verify(response, Mockito.times(3)).sendError(Mockito.anyInt(), Mockito.anyString());
+        Response response2 = Mockito.mock(Response.class);
+        HttpChannel httpChannel = Mockito.mock(HttpChannel.class);
+        Mockito.when(response2.getHttpChannel()).thenReturn(httpChannel);
+        handler.handle(response2, new InterceptException(HttpStatus.PRECONDITION_FAILED_412, "Reach the max tenants [5] restriction"));
+        Mockito.verify(httpChannel).sendResponse(Mockito.any(), Mockito.any(), Mockito.anyBoolean());
+    }
+
+}

pulsar-client-admin/src/main/java/org/apache/pulsar/client/admin/internal/http/AsyncHttpConnector.java

@@ -205,6 +205,22 @@ public Future<?> apply(ClientRequest jerseyRequest, AsyncConnectorCallback callb
             } else {
                 ClientResponse jerseyResponse =
                         new ClientResponse(Status.fromStatusCode(response.getStatusCode()), jerseyRequest);
+                jerseyResponse.setStatusInfo(new javax.ws.rs.core.Response.StatusType() {
+                    @Override
+                    public int getStatusCode() {
+                        return response.getStatusCode();
+                    }
+
+                    @Override
+                    public Status.Family getFamily() {
+                        return Status.Family.familyOf(response.getStatusCode());
+                    }
+
+                    @Override
+                    public String getReasonPhrase() {
+                        return response.getStatusText();
+                    }
+                });
                 response.getHeaders().forEach(e -> jerseyResponse.header(e.getKey(), e.getValue()));
                 if (response.hasResponseBody()) {
                     jerseyResponse.setEntityStream(response.getResponseBodyAsStream());