001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache license, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the license for the specific language governing permissions and
015 * limitations under the license.
016 */
017 package org.apache.logging.log4j.core.layout;
018
019 import java.io.ByteArrayOutputStream;
020 import java.io.IOException;
021 import java.io.OutputStream;
022 import java.io.PrintWriter;
023 import java.io.StringWriter;
024 import java.math.BigDecimal;
025 import java.util.Collections;
026 import java.util.Map;
027 import java.util.zip.DeflaterOutputStream;
028 import java.util.zip.GZIPOutputStream;
029
030 import org.apache.logging.log4j.Level;
031 import org.apache.logging.log4j.core.Layout;
032 import org.apache.logging.log4j.core.LogEvent;
033 import org.apache.logging.log4j.core.config.Node;
034 import org.apache.logging.log4j.core.config.plugins.Plugin;
035 import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
036 import org.apache.logging.log4j.core.config.plugins.PluginElement;
037 import org.apache.logging.log4j.core.config.plugins.PluginFactory;
038 import org.apache.logging.log4j.core.net.Severity;
039 import org.apache.logging.log4j.core.util.Constants;
040 import org.apache.logging.log4j.core.util.KeyValuePair;
041 import org.apache.logging.log4j.status.StatusLogger;
042
043 import com.fasterxml.jackson.core.io.JsonStringEncoder;
044
045 /**
046 * Lays out events in the Graylog Extended Log Format (GELF) 1.1.
047 * <p>
048 * This layout compresses JSON to GZIP or ZLIB (the {@code compressionType}) if log event data is larger than 1024 bytes
049 * (the {@code compressionThreshold}). This layout does not implement chunking.
050 * </p>
051 * <p>
052 * Configure as follows to send to a Graylog2 server:
053 * </p>
054 *
055 * <pre>
056 * <Appenders>
057 * <Socket name="Graylog" protocol="udp" host="graylog.domain.com" port="12201">
058 * <GelfLayout host="someserver" compressionType="GZIP" compressionThreshold="1024">
059 * <KeyValuePair key="additionalField1" value="additional value 1"/>
060 * <KeyValuePair key="additionalField2" value="additional value 2"/>
061 * </GelfLayout>
062 * </Socket>
063 * </Appenders>
064 * </pre>
065 *
066 * @see <a href="http://graylog2.org/gelf">GELF home page</a>
067 * @see <a href="http://graylog2.org/resources/gelf/specification">GELF specification</a>
068 */
069 @Plugin(name = "GelfLayout", category = Node.CATEGORY, elementType = Layout.ELEMENT_TYPE, printObject = true)
070 public final class GelfLayout extends AbstractStringLayout {
071
072 public static enum CompressionType {
073
074 GZIP {
075 @Override
076 public DeflaterOutputStream createDeflaterOutputStream(final OutputStream os) throws IOException {
077 return new GZIPOutputStream(os);
078 }
079 },
080 ZLIB {
081 @Override
082 public DeflaterOutputStream createDeflaterOutputStream(final OutputStream os) throws IOException {
083 return new DeflaterOutputStream(os);
084 }
085 },
086 OFF {
087 @Override
088 public DeflaterOutputStream createDeflaterOutputStream(final OutputStream os) throws IOException {
089 return null;
090 }
091 };
092
093 public abstract DeflaterOutputStream createDeflaterOutputStream(OutputStream os) throws IOException;
094
095 }
096
097 private static final char C = ',';
098 private static final int COMPRESSION_THRESHOLD = 1024;
099 private static final char Q = '\"';
100 private static final String QC = "\",";
101 private static final String QU = "\"_";
102 private static final long serialVersionUID = 1L;
103 private static final BigDecimal TIME_DIVISOR = new BigDecimal(1000);
104
105 @PluginFactory
106 public static GelfLayout createLayout(
107 //@formatter:off
108 @PluginAttribute("host") final String host,
109 @PluginElement("AdditionalField") final KeyValuePair[] additionalFields,
110 @PluginAttribute(value = "compressionType",
111 defaultString = "GZIP") final CompressionType compressionType,
112 @PluginAttribute(value = "compressionThreshold",
113 defaultInt= COMPRESSION_THRESHOLD) final int compressionThreshold) {
114 // @formatter:on
115 return new GelfLayout(host, additionalFields, compressionType, compressionThreshold);
116 }
117
118 /**
119 * http://en.wikipedia.org/wiki/Syslog#Severity_levels
120 */
121 static int formatLevel(final Level level) {
122 return Severity.getSeverity(level).getCode();
123 }
124
125 static String formatThrowable(final Throwable throwable) {
126 // stack traces are big enough to provide a reasonably large initial capacity here
127 final StringWriter sw = new StringWriter(2048);
128 final PrintWriter pw = new PrintWriter(sw);
129 throwable.printStackTrace(pw);
130 pw.flush();
131 return sw.toString();
132 }
133
134 static String formatTimestamp(final long timeMillis) {
135 return new BigDecimal(timeMillis).divide(TIME_DIVISOR).toPlainString();
136 }
137
138 private final KeyValuePair[] additionalFields;
139
140 private final int compressionThreshold;
141
142 private final CompressionType compressionType;
143
144 private final String host;
145
146 public GelfLayout(final String host, final KeyValuePair[] additionalFields, final CompressionType compressionType,
147 final int compressionThreshold) {
148 super(Constants.UTF_8);
149 this.host = host;
150 this.additionalFields = additionalFields;
151 this.compressionType = compressionType;
152 this.compressionThreshold = compressionThreshold;
153 }
154
155 private byte[] compress(final byte[] bytes) {
156 try {
157 final ByteArrayOutputStream baos = new ByteArrayOutputStream(compressionThreshold / 8);
158 final DeflaterOutputStream stream = compressionType.createDeflaterOutputStream(baos);
159 if (stream == null) {
160 return bytes;
161 }
162 stream.write(bytes);
163 stream.finish();
164 stream.close();
165 return baos.toByteArray();
166 } catch (final IOException e) {
167 StatusLogger.getLogger().error(e);
168 return bytes;
169 }
170 }
171
172 @Override
173 public Map<String, String> getContentFormat() {
174 return Collections.emptyMap();
175 }
176
177 @Override
178 public String getContentType() {
179 return JsonLayout.CONTENT_TYPE + "; charset=" + this.getCharset();
180 }
181
182 @Override
183 public byte[] toByteArray(final LogEvent event) {
184 final byte[] bytes = getBytes(toSerializable(event));
185 return bytes.length > compressionThreshold ? compress(bytes) : bytes;
186 }
187
188 @Override
189 public String toSerializable(final LogEvent event) {
190 final StringBuilder builder = new StringBuilder(256);
191 final JsonStringEncoder jsonEncoder = JsonStringEncoder.getInstance();
192 builder.append('{');
193 builder.append("\"version\":\"1.1\",");
194 builder.append("\"host\":\"").append(jsonEncoder.quoteAsString(host)).append(QC);
195 builder.append("\"timestamp\":").append(formatTimestamp(event.getTimeMillis())).append(C);
196 builder.append("\"level\":").append(formatLevel(event.getLevel())).append(C);
197 if (event.getThreadName() != null) {
198 builder.append("\"_thread\":\"").append(jsonEncoder.quoteAsString(event.getThreadName())).append(QC);
199 }
200 if (event.getLoggerName() != null) {
201 builder.append("\"_logger\":\"").append(jsonEncoder.quoteAsString(event.getLoggerName())).append(QC);
202 }
203
204 for (final KeyValuePair additionalField : additionalFields) {
205 builder.append(QU).append(jsonEncoder.quoteAsString(additionalField.getKey())).append("\":\"")
206 .append(jsonEncoder.quoteAsString(additionalField.getValue())).append(QC);
207 }
208 for (final Map.Entry<String, String> entry : event.getContextMap().entrySet()) {
209 builder.append(QU).append(jsonEncoder.quoteAsString(entry.getKey())).append("\":\"")
210 .append(jsonEncoder.quoteAsString(entry.getValue())).append(QC);
211 }
212 if (event.getThrown() != null) {
213 builder.append("\"full_message\":\"").append(jsonEncoder.quoteAsString(formatThrowable(event.getThrown())))
214 .append(QC);
215 }
216
217 builder.append("\"short_message\":\"")
218 .append(jsonEncoder.quoteAsString(event.getMessage().getFormattedMessage())).append(Q);
219 builder.append('}');
220 return builder.toString();
221 }
222 }