gateway-server/src/main/java/org/apache/knox/gateway/GatewayServlet.java - knox - Git at Google

 /*
  * 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.knox.gateway;

 import org.apache.knox.gateway.audit.api.Action;
 import org.apache.knox.gateway.audit.api.ActionOutcome;
 import org.apache.knox.gateway.audit.api.AuditService;
 import org.apache.knox.gateway.audit.api.AuditServiceFactory;
 import org.apache.knox.gateway.audit.api.Auditor;
 import org.apache.knox.gateway.audit.api.ResourceType;
 import org.apache.knox.gateway.audit.log4j.audit.AuditConstants;
 import org.apache.knox.gateway.config.GatewayConfig;
 import org.apache.knox.gateway.descriptor.GatewayDescriptor;
 import org.apache.knox.gateway.descriptor.GatewayDescriptorFactory;
 import org.apache.knox.gateway.filter.AbstractGatewayFilter;
 import org.apache.knox.gateway.i18n.messages.MessagesFactory;
 import org.apache.knox.gateway.i18n.resources.ResourcesFactory;
 import org.apache.knox.gateway.services.ServiceType;
 import org.apache.knox.gateway.services.GatewayServices;
 import org.apache.knox.gateway.services.metrics.MetricsService;
 import org.apache.knox.gateway.util.ServletRequestUtils;

 import javax.servlet.Filter;
 import javax.servlet.FilterChain;
 import javax.servlet.FilterConfig;
 import javax.servlet.Servlet;
 import javax.servlet.ServletConfig;
 import javax.servlet.ServletContext;
 import javax.servlet.ServletException;
 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServletResponse;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.net.URISyntaxException;
 import java.nio.charset.StandardCharsets;
 import java.util.Enumeration;

 public class GatewayServlet implements Servlet, Filter {
   public static final String GATEWAY_DESCRIPTOR_LOCATION_DEFAULT = "gateway.xml";
   public static final String GATEWAY_DESCRIPTOR_LOCATION_PARAM = "gatewayDescriptorLocation";

   private static final GatewayResources res = ResourcesFactory.get( GatewayResources.class );
   private static final GatewayMessages LOG = MessagesFactory.get( GatewayMessages.class );

   private static final AuditService auditService = AuditServiceFactory.getAuditService();
   private static final Auditor auditor = AuditServiceFactory.getAuditService().getAuditor(AuditConstants.DEFAULT_AUDITOR_NAME, AuditConstants.KNOX_SERVICE_NAME,
       AuditConstants.KNOX_COMPONENT_NAME);

   private FilterConfigAdapter filterConfig;
   private GatewayFilter filter;

   public GatewayServlet( GatewayFilter filter ) {
     this.filterConfig = null;
     this.filter = filter;
   }

   public GatewayServlet() {
     this( null );
   }

   public synchronized GatewayFilter getFilter() {
     return filter;
   }

   public synchronized void setFilter( GatewayFilter filter ) throws ServletException {
     if( filterConfig != null ) {
       filter.init( filterConfig );
     }
     this.filter = filter;
     if( filter != null && filterConfig != null ) {
       filter.destroy();
     }
   }

   @Override
   public synchronized void init( ServletConfig servletConfig ) throws ServletException {
     try {
       if( filter == null ) {
         filter = createFilter( servletConfig );
       }
       filterConfig = new FilterConfigAdapter( servletConfig );
       if( filter != null ) {
         filter.init( filterConfig );
       }
     } catch( ServletException | RuntimeException e ) {
       LOG.failedToInitializeServletInstace( e );
       throw e;
     }
   }

   @Override
   public void init( FilterConfig filterConfig ) throws ServletException {
     try {
       if( filter == null ) {
         filter = createFilter( filterConfig );
       }
       if( filter != null ) {
         filter.init( filterConfig );
       }
     } catch( ServletException | RuntimeException e ) {
       LOG.failedToInitializeServletInstace( e );
       throw e;
     }
   }

   @Override
   public ServletConfig getServletConfig() {
     return filterConfig.getServletConfig();
   }

   @Override
   public void service( ServletRequest servletRequest, ServletResponse servletResponse ) throws ServletException, IOException {
     try {
       auditService.createContext();
       GatewayFilter f = filter;
       if( f != null ) {
         try {
           f.doFilter( servletRequest, servletResponse, null );
         } catch( IOException | RuntimeException | ServletException e ) {
           LOG.failedToExecuteFilter( e );
           throw e;
         }
       } else {
         ((HttpServletResponse)servletResponse).setStatus( HttpServletResponse.SC_SERVICE_UNAVAILABLE );
       }
       auditLog(servletRequest, servletResponse);
     } finally {
       auditService.detachContext();
     }
   }

   @Override
   public void doFilter( ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain ) throws IOException, ServletException {
     try {
       auditService.createContext();
       GatewayFilter f = filter;
       if( f != null ) {
         try {
           f.doFilter( servletRequest, servletResponse );

           /* if response is committed in case of SSO redirect no need to apply further filters */
           if(!servletResponse.isCommitted()) {
             //TODO: This should really happen naturally somehow as part of being a filter.  This way will cause problems eventually.
             chain.doFilter( servletRequest, servletResponse );
           }

         } catch( IOException | RuntimeException | ServletException e ) {
           LOG.failedToExecuteFilter( e );
           throw e;
         }
       } else {
         ((HttpServletResponse)servletResponse).setStatus( HttpServletResponse.SC_SERVICE_UNAVAILABLE );
       }
       auditLog(servletRequest, servletResponse);
     } finally {
       auditService.detachContext();
     }
   }

   private void auditLog(ServletRequest servletRequest, ServletResponse servletResponse) {
     final int status = ((HttpServletResponse) servletResponse).getStatus();
     final String requestUri, actionOutcome;
     if (HttpServletResponse.SC_SERVICE_UNAVAILABLE == status) {
       requestUri = ServletRequestUtils.getContextPathWithQuery(servletRequest);
       actionOutcome = ActionOutcome.UNAVAILABLE;
     } else {
       requestUri = (String) servletRequest.getAttribute(AbstractGatewayFilter.SOURCE_REQUEST_CONTEXT_URL_ATTRIBUTE_NAME);
       actionOutcome = ActionOutcome.SUCCESS;
     }
     auditor.audit(Action.ACCESS, requestUri, ResourceType.URI, actionOutcome, res.responseStatus(status));
   }

   @Override
   public String getServletInfo() {
     return res.gatewayServletInfo();
   }

   @Override
   public synchronized void destroy() {
     if( filter != null ) {
       filter.destroy();
     }
     filter = null;
   }

   private static GatewayFilter createFilter( InputStream stream, ServletContext servletContext ) throws ServletException {
     try {
       GatewayFilter filter = null;
       if( stream != null ) {
         try (InputStreamReader reader = new InputStreamReader(stream, StandardCharsets.UTF_8)){
           GatewayDescriptor descriptor = GatewayDescriptorFactory.load("xml", reader);
           filter = GatewayFactory.create( descriptor );
         } finally {
           stream.close();
         }
       }
       GatewayConfig gatewayConfig = (GatewayConfig) servletContext.getAttribute(GatewayConfig.GATEWAY_CONFIG_ATTRIBUTE);
       if (gatewayConfig.isMetricsEnabled()) {
         GatewayServices gatewayServices = (GatewayServices) servletContext.getAttribute(GatewayServices.GATEWAY_SERVICES_ATTRIBUTE);
         MetricsService metricsService = gatewayServices.getService(ServiceType.METRICS_SERVICE);
         if (metricsService != null) {
           GatewayFilter instrumentedFilter = metricsService.getInstrumented(filter);
           if (instrumentedFilter != null) {
             filter = instrumentedFilter;
           }
         }
       }
       return filter;
     } catch( IOException | URISyntaxException e ) {
       throw new ServletException( e );
     }
   }

   private static GatewayFilter createFilter( FilterConfig filterConfig ) throws ServletException {
     GatewayFilter filter;
     InputStream stream;
     String location = filterConfig.getInitParameter( GATEWAY_DESCRIPTOR_LOCATION_PARAM );
     if( location != null ) {
       stream = filterConfig.getServletContext().getResourceAsStream( location );
       if( stream == null ) {
         stream = filterConfig.getServletContext().getResourceAsStream( "/WEB-INF/" + location );
       }
     } else {
       stream = filterConfig.getServletContext().getResourceAsStream( GATEWAY_DESCRIPTOR_LOCATION_DEFAULT );
     }
     filter = createFilter( stream, filterConfig.getServletContext());
     return filter;
   }

   private static GatewayFilter createFilter( ServletConfig servletConfig ) throws ServletException {
     GatewayFilter filter;
     InputStream stream;
     String location = servletConfig.getInitParameter( GATEWAY_DESCRIPTOR_LOCATION_PARAM );
     if( location != null ) {
       stream = servletConfig.getServletContext().getResourceAsStream( location );
       if( stream == null ) {
         stream = servletConfig.getServletContext().getResourceAsStream( "/WEB-INF/" + location );
       }
     } else {
       stream = servletConfig.getServletContext().getResourceAsStream( GATEWAY_DESCRIPTOR_LOCATION_DEFAULT );
     }
     filter = createFilter( stream, servletConfig.getServletContext());
     return filter;
   }

   private static class FilterConfigAdapter implements FilterConfig {

     private ServletConfig config;

     FilterConfigAdapter( ServletConfig config ) {
       this.config = config;
     }

     private ServletConfig getServletConfig() {
       return config;
     }

     @Override
     public String getFilterName() {
       return config.getServletName();
     }

     @Override
     public ServletContext getServletContext() {
       return config.getServletContext();
     }

     @Override
     public String getInitParameter( String name ) {
       return config.getInitParameter( name );
     }

     @Override
     public Enumeration<String> getInitParameterNames() {
       return config.getInitParameterNames();
     }
   }
 }
	/*
	* 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.knox.gateway;

	import org.apache.knox.gateway.audit.api.Action;
	import org.apache.knox.gateway.audit.api.ActionOutcome;
	import org.apache.knox.gateway.audit.api.AuditService;
	import org.apache.knox.gateway.audit.api.AuditServiceFactory;
	import org.apache.knox.gateway.audit.api.Auditor;
	import org.apache.knox.gateway.audit.api.ResourceType;
	import org.apache.knox.gateway.audit.log4j.audit.AuditConstants;
	import org.apache.knox.gateway.config.GatewayConfig;
	import org.apache.knox.gateway.descriptor.GatewayDescriptor;
	import org.apache.knox.gateway.descriptor.GatewayDescriptorFactory;
	import org.apache.knox.gateway.filter.AbstractGatewayFilter;
	import org.apache.knox.gateway.i18n.messages.MessagesFactory;
	import org.apache.knox.gateway.i18n.resources.ResourcesFactory;
	import org.apache.knox.gateway.services.ServiceType;
	import org.apache.knox.gateway.services.GatewayServices;
	import org.apache.knox.gateway.services.metrics.MetricsService;
	import org.apache.knox.gateway.util.ServletRequestUtils;

	import javax.servlet.Filter;
	import javax.servlet.FilterChain;
	import javax.servlet.FilterConfig;
	import javax.servlet.Servlet;
	import javax.servlet.ServletConfig;
	import javax.servlet.ServletContext;
	import javax.servlet.ServletException;
	import javax.servlet.ServletRequest;
	import javax.servlet.ServletResponse;
	import javax.servlet.http.HttpServletResponse;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.InputStreamReader;
	import java.net.URISyntaxException;
	import java.nio.charset.StandardCharsets;
	import java.util.Enumeration;

	public class GatewayServlet implements Servlet, Filter {
	public static final String GATEWAY_DESCRIPTOR_LOCATION_DEFAULT = "gateway.xml";
	public static final String GATEWAY_DESCRIPTOR_LOCATION_PARAM = "gatewayDescriptorLocation";

	private static final GatewayResources res = ResourcesFactory.get( GatewayResources.class );
	private static final GatewayMessages LOG = MessagesFactory.get( GatewayMessages.class );

	private static final AuditService auditService = AuditServiceFactory.getAuditService();
	private static final Auditor auditor = AuditServiceFactory.getAuditService().getAuditor(AuditConstants.DEFAULT_AUDITOR_NAME, AuditConstants.KNOX_SERVICE_NAME,
	AuditConstants.KNOX_COMPONENT_NAME);

	private FilterConfigAdapter filterConfig;
	private GatewayFilter filter;

	public GatewayServlet( GatewayFilter filter ) {
	this.filterConfig = null;
	this.filter = filter;
	}

	public GatewayServlet() {
	this( null );
	}

	public synchronized GatewayFilter getFilter() {
	return filter;
	}

	public synchronized void setFilter( GatewayFilter filter ) throws ServletException {
	if( filterConfig != null ) {
	filter.init( filterConfig );
	}
	this.filter = filter;
	if( filter != null && filterConfig != null ) {
	filter.destroy();
	}
	}

	@Override
	public synchronized void init( ServletConfig servletConfig ) throws ServletException {
	try {
	if( filter == null ) {
	filter = createFilter( servletConfig );
	}
	filterConfig = new FilterConfigAdapter( servletConfig );
	if( filter != null ) {
	filter.init( filterConfig );
	}
	} catch( ServletException \| RuntimeException e ) {
	LOG.failedToInitializeServletInstace( e );
	throw e;
	}
	}

	@Override
	public void init( FilterConfig filterConfig ) throws ServletException {
	try {
	if( filter == null ) {
	filter = createFilter( filterConfig );
	}
	if( filter != null ) {
	filter.init( filterConfig );
	}
	} catch( ServletException \| RuntimeException e ) {
	LOG.failedToInitializeServletInstace( e );
	throw e;
	}
	}

	@Override
	public ServletConfig getServletConfig() {
	return filterConfig.getServletConfig();
	}

	@Override
	public void service( ServletRequest servletRequest, ServletResponse servletResponse ) throws ServletException, IOException {
	try {
	auditService.createContext();
	GatewayFilter f = filter;
	if( f != null ) {
	try {
	f.doFilter( servletRequest, servletResponse, null );
	} catch( IOException \| RuntimeException \| ServletException e ) {
	LOG.failedToExecuteFilter( e );
	throw e;
	}
	} else {
	((HttpServletResponse)servletResponse).setStatus( HttpServletResponse.SC_SERVICE_UNAVAILABLE );
	}
	auditLog(servletRequest, servletResponse);
	} finally {
	auditService.detachContext();
	}
	}

	@Override
	public void doFilter( ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain ) throws IOException, ServletException {
	try {
	auditService.createContext();
	GatewayFilter f = filter;
	if( f != null ) {
	try {
	f.doFilter( servletRequest, servletResponse );

	/* if response is committed in case of SSO redirect no need to apply further filters */
	if(!servletResponse.isCommitted()) {
	//TODO: This should really happen naturally somehow as part of being a filter. This way will cause problems eventually.
	chain.doFilter( servletRequest, servletResponse );
	}

	} catch( IOException \| RuntimeException \| ServletException e ) {
	LOG.failedToExecuteFilter( e );
	throw e;
	}
	} else {
	((HttpServletResponse)servletResponse).setStatus( HttpServletResponse.SC_SERVICE_UNAVAILABLE );
	}
	auditLog(servletRequest, servletResponse);
	} finally {
	auditService.detachContext();
	}
	}

	private void auditLog(ServletRequest servletRequest, ServletResponse servletResponse) {
	final int status = ((HttpServletResponse) servletResponse).getStatus();
	final String requestUri, actionOutcome;
	if (HttpServletResponse.SC_SERVICE_UNAVAILABLE == status) {
	requestUri = ServletRequestUtils.getContextPathWithQuery(servletRequest);
	actionOutcome = ActionOutcome.UNAVAILABLE;
	} else {
	requestUri = (String) servletRequest.getAttribute(AbstractGatewayFilter.SOURCE_REQUEST_CONTEXT_URL_ATTRIBUTE_NAME);
	actionOutcome = ActionOutcome.SUCCESS;
	}
	auditor.audit(Action.ACCESS, requestUri, ResourceType.URI, actionOutcome, res.responseStatus(status));
	}

	@Override
	public String getServletInfo() {
	return res.gatewayServletInfo();
	}

	@Override
	public synchronized void destroy() {
	if( filter != null ) {
	filter.destroy();
	}
	filter = null;
	}

	private static GatewayFilter createFilter( InputStream stream, ServletContext servletContext ) throws ServletException {
	try {
	GatewayFilter filter = null;
	if( stream != null ) {
	try (InputStreamReader reader = new InputStreamReader(stream, StandardCharsets.UTF_8)){
	GatewayDescriptor descriptor = GatewayDescriptorFactory.load("xml", reader);
	filter = GatewayFactory.create( descriptor );
	} finally {
	stream.close();
	}
	}
	GatewayConfig gatewayConfig = (GatewayConfig) servletContext.getAttribute(GatewayConfig.GATEWAY_CONFIG_ATTRIBUTE);
	if (gatewayConfig.isMetricsEnabled()) {
	GatewayServices gatewayServices = (GatewayServices) servletContext.getAttribute(GatewayServices.GATEWAY_SERVICES_ATTRIBUTE);
	MetricsService metricsService = gatewayServices.getService(ServiceType.METRICS_SERVICE);
	if (metricsService != null) {
	GatewayFilter instrumentedFilter = metricsService.getInstrumented(filter);
	if (instrumentedFilter != null) {
	filter = instrumentedFilter;
	}
	}
	}
	return filter;
	} catch( IOException \| URISyntaxException e ) {
	throw new ServletException( e );
	}
	}

	private static GatewayFilter createFilter( FilterConfig filterConfig ) throws ServletException {
	GatewayFilter filter;
	InputStream stream;
	String location = filterConfig.getInitParameter( GATEWAY_DESCRIPTOR_LOCATION_PARAM );
	if( location != null ) {
	stream = filterConfig.getServletContext().getResourceAsStream( location );
	if( stream == null ) {
	stream = filterConfig.getServletContext().getResourceAsStream( "/WEB-INF/" + location );
	}
	} else {
	stream = filterConfig.getServletContext().getResourceAsStream( GATEWAY_DESCRIPTOR_LOCATION_DEFAULT );
	}
	filter = createFilter( stream, filterConfig.getServletContext());
	return filter;
	}

	private static GatewayFilter createFilter( ServletConfig servletConfig ) throws ServletException {
	GatewayFilter filter;
	InputStream stream;
	String location = servletConfig.getInitParameter( GATEWAY_DESCRIPTOR_LOCATION_PARAM );
	if( location != null ) {
	stream = servletConfig.getServletContext().getResourceAsStream( location );
	if( stream == null ) {
	stream = servletConfig.getServletContext().getResourceAsStream( "/WEB-INF/" + location );
	}
	} else {
	stream = servletConfig.getServletContext().getResourceAsStream( GATEWAY_DESCRIPTOR_LOCATION_DEFAULT );
	}
	filter = createFilter( stream, servletConfig.getServletContext());
	return filter;
	}

	private static class FilterConfigAdapter implements FilterConfig {

	private ServletConfig config;

	FilterConfigAdapter( ServletConfig config ) {
	this.config = config;
	}

	private ServletConfig getServletConfig() {
	return config;
	}

	@Override
	public String getFilterName() {
	return config.getServletName();
	}

	@Override
	public ServletContext getServletContext() {
	return config.getServletContext();
	}

	@Override
	public String getInitParameter( String name ) {
	return config.getInitParameter( name );
	}

	@Override
	public Enumeration<String> getInitParameterNames() {
	return config.getInitParameterNames();
	}
	}
	}