AMBARI-9016: Ambari API uses HTTP Header Content-Type:text/plain when… (#3481)

ambari-server/src/main/java/org/apache/ambari/server/api/ContentTypeOverrideFilter.java

@@ -0,0 +1,182 @@
+/*
+ * 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.ambari.server.api;
+
+import java.io.IOException;
+import java.lang.reflect.Method;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.HashSet;
+import java.util.Set;
+
+import javax.servlet.Filter;
+import javax.servlet.FilterChain;
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletRequestWrapper;
+import javax.servlet.http.HttpServletResponse;
+import javax.servlet.http.HttpServletResponseWrapper;
+import javax.ws.rs.Consumes;
+import javax.ws.rs.Path;
+import javax.ws.rs.core.HttpHeaders;
+import javax.ws.rs.core.MediaType;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.collect.ImmutableSet;
+import com.google.common.reflect.ClassPath;
+
+
+/**
+ * Filter to work around the original limitation of the REST API implementation of Amabri,
+ * where the Content-Type is always text/plain, despite the accepted/returned JSON content.
+ * When the request uses application/json as Content-Type, Ambari fails.
+ *
+ * This workaround is replacing application/json Content-Type to text/plain in requests, thus
+ * preventing the failure.
+ *
+ * Furthermore the response is also tweaked by changing the Content-Type to application/json
+ * when the original Content-Type of the request was application/json.
+ */
+public class ContentTypeOverrideFilter implements Filter {
+
+    private static final Logger logger = LoggerFactory.getLogger(ContentTypeOverrideFilter.class);
+
+    private final Set<String> excludedUrls = new HashSet<>();
+
+    class ContentTypeOverrideRequestWrapper extends HttpServletRequestWrapper {
+
+        public ContentTypeOverrideRequestWrapper(HttpServletRequest request) {
+            super(request);
+        }
+
+        @Override
+        public Enumeration<String> getHeaders(String name) {
+            Enumeration<String> headerValues = super.getHeaders(name);
+            if (HttpHeaders.CONTENT_TYPE.equals(name)) {
+                Set<String> newContentTypeValues = new HashSet<>();
+                while (headerValues.hasMoreElements()) {
+                    String value = headerValues.nextElement();
+                    if(value != null && value.startsWith(MediaType.APPLICATION_JSON)) {
+                        newContentTypeValues.add(value.replace(MediaType.APPLICATION_JSON, MediaType.TEXT_PLAIN));
+                    } else {
+                        newContentTypeValues.add(value);
+                    }
+                }
+                return Collections.enumeration(newContentTypeValues);
+            }
+            return headerValues;
+        }
+
+        @Override
+        public String getHeader(String name) {
+            if (HttpHeaders.CONTENT_TYPE.equals(name)) {
+                String header = super.getHeader(name);
+                if (header != null && header.startsWith(MediaType.APPLICATION_JSON)) {
+                    return header.replace(MediaType.APPLICATION_JSON, MediaType.TEXT_PLAIN);
+                }
+            }
+            return super.getHeader(name);
+        }
+    }
+
+    class ContentTypeOverrideResponseWrapper extends HttpServletResponseWrapper {
+
+        public ContentTypeOverrideResponseWrapper(HttpServletResponse response) {
+            super(response);
+            super.setContentType(MediaType.APPLICATION_JSON);
+        }
+
+        @Override
+        public void setHeader(String name, String value) {
+            if (!HttpHeaders.CONTENT_TYPE.equals(name)) {
+                super.setHeader(name, value);
+            }
+        }
+
+        @Override
+        public void addHeader(String name, String value) {
+            if (!HttpHeaders.CONTENT_TYPE.equals(name)) {
+                super.addHeader(name, value);
+            }
+        }
+
+        @Override
+        public void setContentType(String type) {
+            // Ignore changing the content type
+        }
+    }
+
+    @Override
+    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
+        if (request instanceof HttpServletRequest) {
+            HttpServletRequest httpServletRequest = (HttpServletRequest) request;
+            String contentType = httpServletRequest.getContentType();
+
+            if (contentType != null && contentType.startsWith(MediaType.APPLICATION_JSON) && !excludedUrls.contains(httpServletRequest.getPathInfo())) {
+                ContentTypeOverrideRequestWrapper requestWrapper = new ContentTypeOverrideRequestWrapper(httpServletRequest);
+                ContentTypeOverrideResponseWrapper responseWrapper = new ContentTypeOverrideResponseWrapper((HttpServletResponse) response);
+
+                chain.doFilter(requestWrapper, responseWrapper);
+                return;
+            }
+        }
+
+        chain.doFilter(request, response);
+    }
+
+    @Override
+    public void init(FilterConfig filterConfig) throws ServletException {
+        try {
+            ClassPath classPath = ClassPath.from(ClassLoader.getSystemClassLoader());
+            ImmutableSet<ClassPath.ClassInfo> classes = classPath.getTopLevelClassesRecursive("org.apache.ambari.server.api");
+
+            restart:
+            for (ClassPath.ClassInfo classInfo: classes) {
+                Class<?> clazz = classInfo.load();
+                if (clazz.isAnnotationPresent(Path.class)) {
+                    Path path = clazz.getAnnotation(Path.class);
+                    for (Method method : clazz.getMethods()) {
+                        if (method.isAnnotationPresent(Consumes.class)) {
+                            Consumes consumesAnnotation = method.getAnnotation(Consumes.class);
+                            for (String consume : consumesAnnotation.value()) {
+                                if (MediaType.APPLICATION_JSON.equals(consume)) {
+                                    excludedUrls.add(path.value());
+                                    continue restart;
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        } catch (Exception e) {
+            logger.error("Failed to discover URLs that are excluded from Content-Type override. Falling back to pre-defined list of exluded URLs.", e);
+
+            /* Do not fail here, but fallback to manual definition of excluded endpoints. */
+            excludedUrls.add("/bootstrap");
+        }
+    }
+
+    @Override
+    public void destroy() {
+    }
+}

ambari-server/src/main/java/org/apache/ambari/server/controller/AmbariServer.java

@@ -42,6 +42,7 @@ import org.apache.ambari.server.agent.HeartBeatHandler;
 import org.apache.ambari.server.agent.rest.AgentResource;
 import org.apache.ambari.server.api.AmbariErrorHandler;
 import org.apache.ambari.server.api.AmbariPersistFilter;
+import org.apache.ambari.server.api.ContentTypeOverrideFilter;
 import org.apache.ambari.server.api.MethodOverrideFilter;
 import org.apache.ambari.server.api.UserNameOverrideFilter;
 import org.apache.ambari.server.api.rest.BootStrapResource;
@@ -419,6 +420,7 @@ public class AmbariServer {
       // session-per-request strategy for api
       root.addFilter(new FilterHolder(injector.getInstance(AmbariPersistFilter.class)), "/api/*", DISPATCHER_TYPES);
       root.addFilter(new FilterHolder(new MethodOverrideFilter()), "/api/*", DISPATCHER_TYPES);
+      root.addFilter(new FilterHolder(new ContentTypeOverrideFilter()), "/api/*", DISPATCHER_TYPES);
 
       // register listener to capture request context
       root.addEventListener(new RequestContextListener());

ambari-server/src/test/java/org/apache/ambari/server/api/ContentTypeOverrideFilterTest.java

@@ -0,0 +1,87 @@
+/*
+ * 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.ambari.server.api;
+
+import static org.easymock.EasyMock.expect;
+
+import java.io.IOException;
+import java.util.Vector;
+
+import javax.servlet.FilterChain;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.ws.rs.core.HttpHeaders;
+import javax.ws.rs.core.MediaType;
+
+import org.easymock.EasyMockRule;
+import org.easymock.EasyMockSupport;
+import org.easymock.Mock;
+import org.easymock.MockType;
+import org.junit.Rule;
+import org.junit.Test;
+
+import junit.framework.Assert;
+
+
+public class ContentTypeOverrideFilterTest extends EasyMockSupport {
+
+    private class FilterChainMock implements FilterChain {
+        HttpServletResponse response;
+        HttpServletRequest request;
+
+        @Override
+        public void doFilter(ServletRequest request, ServletResponse response) throws IOException, ServletException {
+            this.request = (HttpServletRequest) request;
+            this.response = (HttpServletResponse) response;
+        }
+    }
+
+    @Rule
+    public EasyMockRule mock = new EasyMockRule(this);
+
+    @Mock(type = MockType.NICE)
+    private HttpServletRequest request;
+
+    @Mock(type = MockType.NICE)
+    private HttpServletResponse response;
+
+    private final ContentTypeOverrideFilter filter = new ContentTypeOverrideFilter();
+
+    @Test
+    public void testJSONContentTypeRequest() throws Exception {
+        Vector<String> headers = new Vector<>(1);
+        headers.add(MediaType.APPLICATION_JSON);
+
+        expect(request.getContentType()).andReturn(MediaType.APPLICATION_JSON).atLeastOnce();
+        expect(request.getHeader(HttpHeaders.CONTENT_TYPE)).andReturn(MediaType.APPLICATION_JSON).atLeastOnce();
+        expect(request.getHeaders(HttpHeaders.CONTENT_TYPE)).andReturn(headers.elements()).atLeastOnce();
+        replayAll();
+
+        FilterChainMock chain = new FilterChainMock();
+        filter.doFilter(request, response, chain);
+
+        Assert.assertEquals(MediaType.TEXT_PLAIN, chain.request.getHeader(HttpHeaders.CONTENT_TYPE));
+        Assert.assertEquals(MediaType.TEXT_PLAIN, chain.request.getHeaders(HttpHeaders.CONTENT_TYPE).nextElement());
+
+        verifyAll();
+    }
+}