001/**
002 * Copyright (C) 2006-2020 Talend Inc. - www.talend.com
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.talend.sdk.component.server.mdc;
017
018import static java.util.Optional.ofNullable;
019
020import java.io.IOException;
021import java.net.InetAddress;
022import java.net.UnknownHostException;
023import java.util.HashMap;
024import java.util.Map;
025
026import javax.enterprise.inject.Vetoed;
027import javax.servlet.Filter;
028import javax.servlet.FilterChain;
029import javax.servlet.FilterConfig;
030import javax.servlet.ServletException;
031import javax.servlet.ServletRequest;
032import javax.servlet.ServletResponse;
033import javax.servlet.http.HttpServletRequest;
034
035import org.apache.logging.log4j.ThreadContext;
036
037@Vetoed
038public class MdcRequestBinder implements Filter {
039
040    private String hostname;
041
042    @Override
043    public void init(final FilterConfig filterConfig) {
044        try {
045            hostname = InetAddress.getLocalHost().getHostName();
046        } catch (UnknownHostException e) {
047            hostname = ofNullable(System.getenv("HOST")).orElse("unknown");
048        }
049    }
050
051    @Override
052    public void doFilter(final ServletRequest request, final ServletResponse response, final FilterChain chain)
053            throws IOException, ServletException {
054        if (HttpServletRequest.class.isInstance(request)) {
055            ThreadContext.putAll(createContext(HttpServletRequest.class.cast(request)));
056        }
057        chain.doFilter(request, response);
058    }
059
060    private Map<String, String> createContext(final HttpServletRequest req) {
061        final Map<String, String> map = new HashMap<>();
062        ofNullable(req.getHeader("X-B3-TraceId")).ifPresent(v -> map.put("spanId", v));
063        ofNullable(req.getHeader("X-B3-SpanId")).ifPresent(v -> map.put("traceId", v));
064        map.put("hostname", hostname);
065        return map;
066    }
067}