最新要做一个对Linux系统日志采集的需求，当然除了Linux的系统日志采集外，还需要转发Tomcat日志，或者Nginx日志等。所以就使用了rsyslog这个比较常用并且功能比较强大的工具。
版本：
- Rsyslog V5
- Logstash 5.2.2
配置文件
就不做过多的介绍了直接贴测试通过的rsyslog.conf配置文件该配置文件的目录为：/etc/rsyslog.conf
# rsyslog v5 configuration file# For more information see /usr/share/doc/rsyslog-*/rsyslog_conf.html# If you experience problems, see http://www.rsyslog.com/doc/troubleshoot.html#### MODULES ####$ModLoad imuxsock # provides support for local system logging (e.g. via logger command)$ModLoad imklog # provides kernel logging support (previously done by rklogd)#$ModLoad immark # provides --MARK-- message capability# Provides UDP syslog reception#$ModLoad imudp#$UDPServerRun 514# Provides TCP syslog reception#$ModLoad imtcp#$InputTCPServerRun 514#### GLOBAL DIRECTIVES ##### Use default timestamp format$ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat# File syncing capability is disabled by default. This feature is usually not required,# not useful and an extreme performance hit#$ActionFileEnableSync on# Include all config files in /etc/rsyslog.d/$IncludeConfig /etc/rsyslog.d/*.conf#### RULES ##### Log all kernel messages to the console.# Logging much else clutters up the screen.(内核)kern.* /dev/console# Log anything (except mail) of level info or higher.# Don't log private authentication messages!(记录的内核消息、各种服务的公共消息，报错信息等)*.info;mail.none;authpriv.none;cron.none /var/log/messages# The authpriv file has restricted access.(包含验证和授权方面信息)authpriv.* /var/log/secure# Log all the mail messages in one place.(包含来着系统运行电子邮件服务器的日志信息)mail.* -/var/log/maillog# Log cron stuff(每当cron进程开始一个工作时，就会将相关信息记录在这个文件中)cron.* /var/log/cron# Everybody gets emergency messages*.emerg *# Save news errors of level crit and higher in a special file.uucp,news.crit /var/log/spooler# Save boot messages also to boot.log(自定义的消息)local7.* /var/log/boot.log$ModLoad imfile #装载imfile模块$InputFileName /opt/tomcat/apache-tomcat-8.5.15/logs/catalina.out #读取日志文件$InputFileTag catalina: #日志写入日志附加标签字符串$InputFileFacility local5 #日志类型$InputFileSeverity info #日志等级$InputFileStateFile ssologs.log_state #定义记录偏移量数据文件名$InputFilePollInterval 1 #检查日志文件间隔（秒）$InputFilePersistStateInterval 1 #回写偏移量数据到文件间隔时间（秒）$InputRunFileMonitor #激活读取，可以设置多组日志读取，每组结束时设置本参数。以示生效。$InputFileName /opt/tomcat/apache-tomcat-8.5.15/logs/localhost_access_log.%$year%-%$month%-%$day%.txt #读取日志文件$InputFileTag access: #日志写入日志附加标签字符串$InputFileFacility local6 #日志类型$InputFileSeverity info #日志等级$InputFileStateFile sssologs.log_state #定义记录偏移量数据文件名$InputFilePollInterval 1 #检查日志文件间隔（秒）$InputFilePersistStateInterval 1 #回写偏移量数据到文件间隔时间（秒）$InputRunFileMonitor #激活读取，可以设置多组日志读取，每组结束时设置本参数。以示生效。# ### begin forwarding rule #### The statement between the begin ... end define a SINGLE forwarding# rule. They belong together, do NOT split them. If you create multiple# forwarding rules, duplicate the whole block!# Remote Logging (we use TCP for reliable delivery)## An on-disk queue is created for this action. If the remote host is# down, messages are spooled to disk and sent when it is up again.#$WorkDirectory /var/lib/rsyslog # where to place spool files#$ActionQueueFileName fwdRule1 # unique name prefix for spool files#$ActionQueueMaxDiskSpace 1g # 1gb space limit (use as much as possible)#$ActionQueueSaveOnShutdown on # save messages to disk on shutdown#$ActionQueueType LinkedList # run asynchronously#$ActionResumeRetryCount -1 # infinite retries if host is down# remote host is: name/ip:port, e.g. 192.168.0.1:514, port optional*.* @10.255.0.167:514# ### end of the forwarding rule #### A template to for higher precision timestamps + severity logging$template SpiceTmpl,"%TIMESTAMP%.%TIMESTAMP:::date-subseconds% %syslogtag% %syslogseverity-text%:%msg:::sp-if-no-1st-sp%%msg:::drop-last-lf%\n":programname, startswith, "spice-vdagent" /var/log/spice-vdagent.log;SpiceTmpl上面文件中：
#*.* @remote-host:514 *.*即表示转发所有设备的日志信息 @表示使用UDP协议传输 @@表示使用TCP协议传输 找到上面这句去掉前面的#号然后添加对应的IP和端口即可。 例： *.* @10.255.0.165:514
如果你只想要转发服务器上的指定设备的日志消息，比如说内核设备，那么你可以在rsyslog配置文件中使用以下声明。 kern.* @10.255.0.165:514
修改完成后执行service rsyslog restart 重新启动rsyslong 即可。
Logstash配置
input { udp { port => 514 type => syslog }}filter { if [type] == "syslog" { grok { patterns_dir => "/opt/logstash/logstash-5.2.2/patterns" match => { "message" => "%{SYSLOGTIMESTAMP:timestamp} %{SYSLOGHOST:syslog_hostname} %{DATA:syslog_program}(?:\[%{POSINT:syslog_pid}\])?: %{GREEDYDATA:syslog_message}" } } }}output{ elasticsearch { hosts => ["10.255.0.167"] index => "rsyslog_test" } stdout{ codec => rubydebug }}最后更新配置：/etc/init.d/rsyslog restart 附：Logstash的配置很简单只是监听514端口就可以了，但是使用grok切日志才是麻烦的，毕竟那么多种的日志每种都要写对应的正则。
