| 1 | /* |
| 2 | * SPDX-License-Identifier: LGPL-2.1-only |
| 3 | * |
| 4 | * Copyright (C) 2015-2022 EfficiOS Inc. |
| 5 | * Copyright (C) 2015 Alexandre Montplaisir <alexmonthy@efficios.com> |
| 6 | * Copyright (C) 2014 Christian Babeux <christian.babeux@efficios.com> |
| 7 | */ |
| 8 | |
| 9 | package org.lttng.ust.agent.log4j2; |
| 10 | |
| 11 | import java.io.IOException; |
| 12 | import java.util.Collection; |
| 13 | import java.util.Map; |
| 14 | import java.util.Map.Entry; |
| 15 | import java.util.concurrent.TimeUnit; |
| 16 | import java.util.concurrent.atomic.AtomicLong; |
| 17 | |
| 18 | import org.apache.logging.log4j.core.Appender; |
| 19 | import org.apache.logging.log4j.core.Core; |
| 20 | import org.apache.logging.log4j.core.Filter; |
| 21 | import org.apache.logging.log4j.core.LogEvent; |
| 22 | import org.apache.logging.log4j.core.appender.AbstractAppender; |
| 23 | import org.apache.logging.log4j.core.config.Property; |
| 24 | import org.apache.logging.log4j.core.config.plugins.Plugin; |
| 25 | import org.apache.logging.log4j.core.config.plugins.PluginAttribute; |
| 26 | import org.apache.logging.log4j.core.config.plugins.PluginElement; |
| 27 | import org.apache.logging.log4j.core.config.plugins.PluginFactory; |
| 28 | import org.apache.logging.log4j.message.Message; |
| 29 | import org.lttng.ust.agent.ILttngAgent.Domain; |
| 30 | import org.lttng.ust.agent.ILttngHandler; |
| 31 | import org.lttng.ust.agent.context.ContextInfoSerializer; |
| 32 | |
| 33 | /** |
| 34 | * LTTng-UST Log4j 2.x log handler. |
| 35 | * |
| 36 | * Applications can attach this appender to their |
| 37 | * {@link org.apache.log4j.Logger} to have it generate UST events from logging |
| 38 | * events received through the logger. |
| 39 | * |
| 40 | * It sends its events to UST via the JNI library "liblttng-ust-log4j-jni.so". |
| 41 | * Make sure this library is available before using this appender. |
| 42 | * |
| 43 | */ |
| 44 | @Plugin(name = LttngLogAppender.PLUGIN_NAME, category = Core.CATEGORY_NAME, elementType = Appender.ELEMENT_TYPE, printObject = false) |
| 45 | public final class LttngLogAppender extends AbstractAppender implements ILttngHandler { |
| 46 | |
| 47 | /** |
| 48 | * The name of the appender in the configuration. |
| 49 | */ |
| 50 | public static final String PLUGIN_NAME = "Lttng"; |
| 51 | |
| 52 | private static final String SHARED_OBJECT_NAME = "lttng-ust-log4j-jni"; |
| 53 | |
| 54 | /** |
| 55 | * Number of events logged (really sent through JNI) by this handler |
| 56 | */ |
| 57 | private final AtomicLong eventCount = new AtomicLong(0); |
| 58 | |
| 59 | private final LttngLog4j2Agent agent; |
| 60 | |
| 61 | /** |
| 62 | * Constructor |
| 63 | * |
| 64 | * @param name The name of the Appender. |
| 65 | * @param domain The LTTng-UST agent domain 'LOG4J' / 'LOG4J2'. |
| 66 | * @param filter The Filter or null. |
| 67 | * @param ignoreExceptions If {@code "true"} exceptions encountered when |
| 68 | * appending events are logged; otherwise they are |
| 69 | * propagated to the caller. |
| 70 | * |
| 71 | * @throws IOException This handler requires the |
| 72 | * lttng-ust-log4j-jni.so native library, |
| 73 | * through which it will send the trace events. |
| 74 | * This exception is thrown if this library |
| 75 | * cannot be found. |
| 76 | * @throws IllegalArgumentException If the provided domain is unsupported. |
| 77 | * @throws SecurityException We will forward any SecurityExcepion that |
| 78 | * may be thrown when trying to load the JNI |
| 79 | * library. |
| 80 | */ |
| 81 | protected LttngLogAppender(String name, LttngLog4j2Agent.Domain domain, Filter filter, boolean ignoreExceptions) |
| 82 | throws IOException, IllegalArgumentException, SecurityException { |
| 83 | |
| 84 | super(name, filter, null, ignoreExceptions, Property.EMPTY_ARRAY); |
| 85 | |
| 86 | /* Initialize LTTng UST tracer. */ |
| 87 | try { |
| 88 | System.loadLibrary(SHARED_OBJECT_NAME); // $NON-NLS-1$ |
| 89 | } catch (UnsatisfiedLinkError e) { |
| 90 | throw new IOException(e); |
| 91 | } |
| 92 | |
| 93 | /* Register to the relevant agent. */ |
| 94 | if (domain == LttngLog4j2Agent.Domain.LOG4J) { |
| 95 | agent = LttngLog4j2Agent.getLog4j1Instance(); |
| 96 | } else if (domain == LttngLog4j2Agent.Domain.LOG4J2) { |
| 97 | agent = LttngLog4j2Agent.getLog4j2Instance(); |
| 98 | } else { |
| 99 | throw new IllegalArgumentException("Unsupported domain '" + domain + "'"); |
| 100 | } |
| 101 | |
| 102 | agent.registerHandler(this); |
| 103 | } |
| 104 | |
| 105 | /** |
| 106 | * Create an LttngLogAppender. |
| 107 | * |
| 108 | * @param name The name of the Appender, null returns null. |
| 109 | * @param domain The LTTng-UST agent domain 'LOG4J' / 'LOG4J2'. |
| 110 | * @param ignoreExceptions If {@code "true"} (default) exceptions encountered |
| 111 | * when appending events are logged; otherwise they are |
| 112 | * propagated to the caller. |
| 113 | * @param filter The Filter or null. |
| 114 | * |
| 115 | * @return A new LttngLogAppender, null if the name was null or the domain is |
| 116 | * null or invalid. |
| 117 | */ |
| 118 | @PluginFactory |
| 119 | public static LttngLogAppender createAppender(@PluginAttribute("name") String name, |
| 120 | @PluginAttribute("domain") String domain, @PluginAttribute("ignoreExceptions") Boolean ignoreExceptions, |
| 121 | @PluginElement("Filters") Filter filter) { |
| 122 | |
| 123 | if (name == null) { |
| 124 | LOGGER.error("No name provided for LttngLogAppender"); |
| 125 | return null; |
| 126 | } |
| 127 | |
| 128 | if (domain == null) { |
| 129 | LOGGER.error("No domain provided for LttngLogAppender"); |
| 130 | return null; |
| 131 | } |
| 132 | |
| 133 | if (ignoreExceptions == null) { |
| 134 | ignoreExceptions = true; |
| 135 | } |
| 136 | |
| 137 | /* Parse the domain string */ |
| 138 | LttngLog4j2Agent.Domain parsedDomain; |
| 139 | try { |
| 140 | parsedDomain = LttngLog4j2Agent.Domain.valueOf(domain.toUpperCase()); |
| 141 | } catch (IllegalArgumentException e) { |
| 142 | LOGGER.error("Invalid domain '{}' for LttngLogAppender", domain); |
| 143 | return null; |
| 144 | } |
| 145 | |
| 146 | /* Create the appender and handle the possible failures. */ |
| 147 | LttngLogAppender newAppender; |
| 148 | try { |
| 149 | newAppender = new LttngLogAppender(name, parsedDomain, filter, ignoreExceptions); |
| 150 | } catch (IllegalArgumentException e) { |
| 151 | LOGGER.error("Invalid domain '{}' for LttngLogAppender", parsedDomain); |
| 152 | newAppender = null; |
| 153 | } catch (SecurityException e) { |
| 154 | LOGGER.error("Security error trying to load '{}' JNI library for LttngLogAppender", SHARED_OBJECT_NAME); |
| 155 | newAppender = null; |
| 156 | } catch (IOException e) { |
| 157 | LOGGER.error("Failed to load '{}' JNI library for LttngLogAppender", SHARED_OBJECT_NAME); |
| 158 | newAppender = null; |
| 159 | } |
| 160 | |
| 161 | return newAppender; |
| 162 | } |
| 163 | |
| 164 | @Override |
| 165 | public synchronized void close() { |
| 166 | agent.unregisterHandler(this); |
| 167 | } |
| 168 | |
| 169 | @Override |
| 170 | public void stop() { |
| 171 | close(); |
| 172 | super.stop(); |
| 173 | |
| 174 | getStatusLogger().debug("Appender Lttng stopped"); |
| 175 | } |
| 176 | |
| 177 | @Override |
| 178 | public boolean stop(final long timeout, final TimeUnit timeUnit) { |
| 179 | close(); |
| 180 | boolean status = super.stop(timeout, timeUnit); |
| 181 | |
| 182 | getStatusLogger().debug("Appender Lttng stopped with status " + status); |
| 183 | |
| 184 | return status; |
| 185 | } |
| 186 | |
| 187 | /** |
| 188 | * Get the number of events logged by this handler so far. This means the number |
| 189 | * of events actually sent through JNI to UST. |
| 190 | * |
| 191 | * @return The number of events logged so far |
| 192 | */ |
| 193 | @Override |
| 194 | public long getEventCount() { |
| 195 | return eventCount.get(); |
| 196 | } |
| 197 | |
| 198 | @Override |
| 199 | public void append(LogEvent event) { |
| 200 | /* |
| 201 | * Check if the current message should be logged, according to the UST session |
| 202 | * settings. |
| 203 | */ |
| 204 | String loggername = event.getLoggerName(); |
| 205 | if (loggername == null || !agent.isEventEnabled(loggername)) { |
| 206 | return; |
| 207 | } |
| 208 | |
| 209 | /* |
| 210 | * Default value if the Message is null. |
| 211 | */ |
| 212 | String message = ""; |
| 213 | |
| 214 | Message eventMessage = event.getMessage(); |
| 215 | if (eventMessage != null) { |
| 216 | message = eventMessage.getFormattedMessage(); |
| 217 | } |
| 218 | |
| 219 | /* |
| 220 | * Default values if the StackTraceElement is null. |
| 221 | */ |
| 222 | String classname = ""; |
| 223 | String methodname = ""; |
| 224 | String filename = ""; |
| 225 | int line = -1; |
| 226 | |
| 227 | StackTraceElement ste = event.getSource(); |
| 228 | if (ste != null) { |
| 229 | classname = ste.getClassName(); |
| 230 | methodname = ste.getMethodName(); |
| 231 | filename = ste.getFileName(); |
| 232 | line = ste.getLineNumber(); |
| 233 | } |
| 234 | |
| 235 | /* Retrieve all the requested context information we can find. */ |
| 236 | Collection<Entry<String, Map<String, Integer>>> enabledContexts = agent.getEnabledAppContexts(); |
| 237 | ContextInfoSerializer.SerializedContexts contextInfo = ContextInfoSerializer |
| 238 | .queryAndSerializeRequestedContexts(enabledContexts); |
| 239 | |
| 240 | eventCount.incrementAndGet(); |
| 241 | |
| 242 | LttngLog4j2Api.tracepointWithContext(message, loggername, classname, methodname, filename, line, |
| 243 | event.getTimeMillis(), event.getLevel().intLevel(), event.getThreadName(), |
| 244 | contextInfo.getEntriesArray(), contextInfo.getStringsArray(), agent.getDomain() == Domain.LOG4J); |
| 245 | } |
| 246 | } |