/**
* 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.hadoop.gateway.hostmap.impl;
import org.apache.hadoop.gateway.filter.rewrite.api.UrlRewriteEnvironment;
import org.apache.hadoop.gateway.filter.rewrite.spi.UrlRewriteContext;
import org.apache.hadoop.gateway.filter.rewrite.spi.UrlRewriteFunctionProcessor;
import org.apache.hadoop.gateway.hostmap.api.HostmapFunctionDescriptor;
import org.apache.hadoop.gateway.services.GatewayServices;
import org.apache.hadoop.gateway.services.hostmap.FileBasedHostMapper;
import org.apache.hadoop.gateway.services.hostmap.HostMapper;
import org.apache.hadoop.gateway.services.hostmap.HostMapperService;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
public class HostmapFunctionProcessor
implements UrlRewriteFunctionProcessor<HostmapFunctionDescriptor> {
public static final String DESCRIPTOR_DEFAULT_FILE_NAME = "hostmap.txt";
public static final String DESCRIPTOR_DEFAULT_LOCATION = "/WEB-INF/" + DESCRIPTOR_DEFAULT_FILE_NAME;
private HostMapperService hostMapperService;
private HostMapper hostMapper = null;
private String clusterName;
@Override
public String name() {
return HostmapFunctionDescriptor.FUNCTION_NAME;
}
@Override
public void initialize( UrlRewriteEnvironment environment, HostmapFunctionDescriptor descriptor ) throws Exception {
URL url = environment.getResource( DESCRIPTOR_DEFAULT_LOCATION );
hostMapper = new FileBasedHostMapper( url );
clusterName = environment.getAttribute( GatewayServices.GATEWAY_CLUSTER_ATTRIBUTE );
GatewayServices services = environment.getAttribute( GatewayServices.GATEWAY_SERVICES_ATTRIBUTE );
if( clusterName != null && services != null ) {
hostMapperService = services.getService( GatewayServices.HOST_MAPPING_SERVICE );
if( hostMapperService != null ) {
hostMapperService.registerHostMapperForCluster( clusterName, hostMapper );
}
}
}
@Override
public void destroy() throws Exception {
if( hostMapperService != null && clusterName != null ) {
hostMapperService.removeHostMapperForCluster( clusterName );
}
}
@Override
public List<String> resolve( UrlRewriteContext context, List<String> parameters ) throws Exception {
List<String> result = null;
if( parameters != null ) {
result = new ArrayList<String>( parameters.size() );
for( String parameter : parameters ) {
switch( context.getDirection() ) {
case IN:
parameter = hostMapper.resolveInboundHostName( parameter );
break;
case OUT:
parameter = hostMapper.resolveOutboundHostName( parameter );
break;
}
result.add( parameter );
}
// System.out.println( "HOSTMAP: " + parameter + "->" + value );
}
return result;
}
}