如何在syslog4j系统日志服务器中解析系统日志消息

Question

我想解析传入syslog4J中实现的syslog服务器的syslog消息。在syslog4J中可以做到这一点吗？

我想要做的是能够分离出syslog消息中的各种字段，如主机名、时间戳、消息、严重级别等，并为将来的分析制定一个统一的syslog模式。

这种功能在rsyslog或syslogNG中可用。

SyslogServerConfigIF config = new TCPNetSyslogServerConfig("0.0.0.0", 1455);
config.setUseStructuredData(true);

SyslogServerIF syslogserver = SyslogServer.getInstance("tcp");
syslogserver.initialize("tcp", config);
syslogserver.run();

Answer 1

首先创建一个新的Event Handler类来处理消息。请注意，解析应该在event()方法中完成，因为将为每个syslog事件调用该方法。

public class SyslogMessageHandler implements SyslogServerSessionEventHandlerIF {

@Override
public void event(Object session, SyslogServerIF syslogServer, 
                  SocketAddress socketAddress, SyslogServerEventIF event) {
    // Simple parsing for Strings in the message
    if (!event.getMessage().contains(" msg=\"")) {
        Logger.getLogger(getClass().getSimpleName()).log(Level.INFO, event.getMessage());
    }

    // You can also build Objects and/or use Pattern/Matcher for parsing.
    MyHTTPLogInfo info = new MyHTTPLogInfo(event.getMessage());
    Pattern myPattern = Pattern.compile("^GET\\s+/([^\\s\\?]*)(\\?\\S*)?\\s+HTTP/1\\.\\d$");
    Matcher matcher = myPattern.matcher(info.getHttpRequest());
    if (matcher.matches()) {
        Logger.getLogger(getClass().getSimpleName()).log(Level.INFO, info.getMyCustomLogOutput());
    }
}

@Override
public void exception(Object session, SyslogServerIF syslogServer, SocketAddress socketAddress, Exception exception) {
    Logger.getLogger(getClass().getSimpleName()).log(Level.INFO, "exception()");
}

@Override
public Object sessionOpened(SyslogServerIF syslogServer, SocketAddress socketAddress) {
    Logger.getLogger(getClass().getSimpleName()).log(Level.INFO, "sessionOpened()");
    return new Date();
}

@Override
public void sessionClosed(Object session, SyslogServerIF syslogServer, SocketAddress socketAddress, boolean timeout) {
    Logger.getLogger(getClass().getSimpleName()).log(Level.INFO, "sessionClosed() {0}", session);
}

@Override
public void initialize(SyslogServerIF syslogServer) {
    Logger.getLogger(getClass().getSimpleName()).log(Level.INFO, "initialize()");
}

@Override
public void destroy(SyslogServerIF syslogServer) {
    Logger.getLogger(getClass().getSimpleName()).log(Level.INFO, "destroy()");
}

最后，在syslog4j配置中将新类注册为EventHandler：

eventHandler = new SyslogMessageHandler(); config.addEventHandler(eventHandler);

然后，您就可以开始测试和调试各种格式和模式了:)