（一）Rsyslog简介
ryslog 是一个快速处理收集系统日志的程序，提供了高性能、安全功能和模块化设计。rsyslog 是syslog 的升级版，它将多种来源输入输出转换结果到目的地。
rsyslog是一个开源工具，被广泛用于Linux系统以通过TCP/UDP协议转发或接收日志消息。rsyslog守护进程可以被配置成两种环境，一种是配置成日志收集服务器，rsyslog进程可以从网络中收集其它主机上的日志数据，这些主机会将日志配置为发送到另外的远程服务器。rsyslog的另外一个用法，就是可以配置为客户端，用来过滤和发送内部日志消息到本地文件夹（如/var/log）或一台可以路由到的远程rsyslog服务器上。
logrotate是一个日志文件管理工具。用来把旧文件轮转、压缩、删除，并且创建新的日志文件。我们可以根据日志文件的大小、天数等来转储，便于对日志文件管理，一般都是通过cron计划任务来完成的。
序号 | IP地址 | 类型 | 备注 |
|---|---|---|---|
1 | 192.168.99.99 | Server端 | |
2 | 192.168.99.98 | client端 |
（二）rsyslog server服务端配置 1，rsyslog默认是安装的，如果没有安装通过 [root@localhost samba]# yum install rsyslog -y
2，修改/etc/rsyslog.conf配置文件，启用udp和tcp模块 $ModLoad imudp $UDPServerRun 514 $ModLoad imtcp $InputTCPServerRun 514
[root@localhost samba]# vim /etc/rsyslog.conf $ModLoad imuxsock # provides support for local system logging (e.g. via logger command) $ModLoad imjournal # provides access to the systemd journal
#####开启udp接收日志 $ModLoad imudp $UDPServerRun 514 $template RemoteHost,"/data/syslog/%$YEAR%-%$MONTH%-%$DAY%/%FROMHOST-IP%.log" *.* ?RemoteHost & ~ ####开启tcp协议接受日志 $ModLoad imtcp $InputTCPServerRun 514
$WorkDirectory /var/lib/rsyslog $ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat
#######启用/etc/rsyslog.d/*.conf目录下所有以.conf结尾的配置文件 $IncludeConfig /etc/rsyslog.d/*.conf
$OmitLocalLogging on $IMJournalStateFile imjournal.state *.info;mail.none;authpriv.none;cron.none /var/log/messages authpriv.* /var/log/secure mail.* -/var/log/maillog cron.* /var/log/cron *.emerg :omusrmsg:* uucp,news.crit /var/log/spooler local7.* /var/log/boot.log local0.* /etc/keepalived/keepalived.log
3,重启rsyslog服务
[root@zabbix 2018-05-23]# systemctl restart rsyslog [root@zabbix 2018-05-23]# systemctl status rsyslog [root@localhost samba]# netstat -anp|grep 514 tcp 0 0 0.0.0.0:514 0.0.0.0:* LISTEN 1445/rsyslogd tcp6 0 0 :::514 :::* LISTEN 1445/rsyslogd udp 0 0 0.0.0.0:514 0.0.0.0:* 1445/rsyslogd udp6 0 0 :::514 :::* 1445/rsyslogd
（三）rsyslog客户端的配置 1，编辑rsylog客户端的配置文件：
[root@server98 log]# grep -v "^$" /etc/rsyslog.conf | grep -v "^#"
$ModLoad imuxsock # provides support for local system logging (e.g. via logger command) $ModLoad imjournal # provides access to the systemd journal $WorkDirectory /var/lib/rsyslog $ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat $template myFormat,"%timestamp% %fromhost-ip% %msg%n" #######自定义模板的相关信息 $IncludeConfig /etc/rsyslog.d/*.conf $OmitLocalLogging on $IMJournalStateFile imjournal.state *.* @192.168.99.99:514 ########该声明告诉rsyslog守护进程，将系统上各个设备的各种日志的所有消息路由到远程rsyslog服务器（192.168.99.99）的UDP端口514。@@是通过tcp传输，一个@是通过udp传输。 *.info;mail.none;authpriv.none;cron.none /var/log/messages authpriv.* /var/log/secure mail.* -/var/log/maillog cron.* /var/log/cron *.emerg :omusrmsg:* uucp,news.crit /var/log/spooler local7.* /var/log/boot.log local0.* /etc/keepalived/keepalived.log
2，重启客户端rsyslog服务
[root@server98 log]# systemctl restart rsyslog [root@server98 log]# systemctl status rsyslog ● rsyslog.service - System Logging Service Loaded: loaded (/usr/lib/systemd/system/rsyslog.service; enabled; vendor preset: enabled) Active: active (running) since 四 2018-05-24 16:57:04 CST; 4s ago Main PID: 44765 (rsyslogd) CGroup: /system.slice/rsyslog.service └─44765 /usr/sbin/rsyslogd -n
5月 24 16:57:04 server98 systemd[1]: Starting System Logging Service... 5月 24 16:57:04 server98 systemd[1]: Started System Logging Service.
（四）查看客户端和服务端的日志是否正常生成。 （1）查看服务端是否在/data/日期/ip.log正常生成。
[root@zabbix 2018-05-24]# tail -f /data/2018-05-24/192.168.99.98.log 2018-05-24T17:02:52 08:00 server98 postfix/pickup[41198]: AAC764ACB03: uid=0 from=<smokealert@company.xy> 2018-05-24T17:02:52 08:00 server98 postfix/cleanup[45967]: AAC764ACB03: message-id=<20180524090252.AAC764ACB03@server98.localdomain> 2018-05-24T17:02:52 08:00 server98 postfix/qmgr[2356]: AAC764ACB03: from=<smokealert@company.xy>, size=851, nrcpt=1 (queue active) 2018-05-24T17:02:52 08:00 server98 postfix/smtp[39596]: AAC764ACB03: to=<alertee@address.somewhere>, relay=none, delay=0, delays=0/0/0/0, dsn=5.4.4, status=bounced (Host or domain name not found. Name service error for name=address.somewhere type=AAAA: Host not found) 2018-05-24T17:02:52 08:00 server98 postfix/cleanup[45967]: AB6804ACB0B: message-id=<20180524090252.AB6804ACB0B@server98.localdomain> 2018-05-24T17:02:52 08:00 server98 postfix/bounce[45968]: AAC764ACB03: sender non-delivery notification: AB6804ACB0B 2018-05-24T17:02:52 08:00 server98 postfix/qmgr[2356]: AB6804ACB0B: from=<>, size=2811, nrcpt=1 (queue active) 2018-05-24T17:02:52 08:00 server98 postfix/qmgr[2356]: AAC764ACB03: removed 2018-05-24T17:02:52 08:00 server98 postfix/smtp[39597]: AB6804ACB0B: to=<smokealert@company.xy>, relay=none, delay=0, delays=0/0/0/0, dsn=5.4.4, status=bounced (Host or domain name not found. Name service error for name=company.xy type=AAAA: Host not found) 2018-05-24T17:02:52 08:00 server98 postfix/qmgr[2356]: AB6804ACB0B: removed 2018-05-24T17:14:33 08:00 server98 root: hello world
（2）在客户端生成日志，是否日志同步，都有 [root@server98 ~]# tail -f /var/log/messages May 24 17:11:40 server98 Keepalived_vrrp[49377]: VRRP_Script(chk_http_port) succeeded May 24 17:11:52 server98 smokeping[38532]: Alert someloss is active for Other.hefei.hefei-office2 May 24 17:11:52 server98 smokeping[38532]: Alert someloss is active for Other.wuxi.wuxi-office2 May 24 17:12:52 server98 smokeping[38532]: Alert someloss is active for Other.hefei.hefei-office2 May 24 17:12:52 server98 smokeping[38532]: Alert someloss is active for Other.wuxi.wuxi-office2 May 24 17:13:52 server98 smokeping[38532]: Alert someloss is active for Other.hefei.hefei-office2 May 24 17:13:52 server98 smokeping[38532]: Alert someloss is active for Other.wuxi.wuxi-office2 May 24 17:14:33 server98 root: hello world
至此，日志服务端和客户端日志同步完成。
备注：
1，Facility是syslog的模块: rsyslog通过facility概念来定义日志消息的来源，以方便对日志进行分类。Facility:有0-23种设备可选，在python的syslog库中有一部分缺失 0 kernel messages 1 user-level messages 2 mail system 3 system daemons 4 security/authorization messages 5 messages generated internally by syslogd 6 line printer subsystem 7 network news subsystem 8 UUCP subsystem 9 clock daemon 10 security/authorization messages 11 FTP daemon 12 NTP subsystem 13 log audit 14 log alert 15 clock daemon 16-23 local0 - local7
常用的有：
2，Severity:日志等级 0 Emergency 1 Alert 2 Critical 3 Error 4 Warning 5 Notice 6 Informational 7 Debug
重要的配置文件：
1，rsyslog server服务端的配置：
[root@zabbix 2018-05-23]# grep -v "^$" /etc/rsyslog.conf | grep -v "^#" $ModLoad imuxsock # provides support for local system logging (e.g. via logger command) $ModLoad imjournal # provides access to the systemd journal $ModLoad imudp $UDPServerRun 514 $template RemoteHost,"/data/%$YEAR%-%$MONTH%-%$DAY%/%FROMHOST-IP%.log" *.* ?RemoteHost & ~ $ModLoad imtcp $InputTCPServerRun 514 $WorkDirectory /var/lib/rsyslog $ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat $IncludeConfig /etc/rsyslog.d/*.conf $OmitLocalLogging on $IMJournalStateFile imjournal.state *.info;mail.none;authpriv.none;cron.none /var/log/messages authpriv.* /var/log/secure mail.* -/var/log/maillog cron.* /var/log/cron *.emerg :omusrmsg:* uucp,news.crit /var/log/spooler local7.* /var/log/boot.log local0.* /etc/keepalived/keepalived.log
2，rsyslog 客户端的配置
[root@server98 log]# grep -v "^$" /etc/rsyslog.conf | grep -v "^#" $ModLoad imuxsock # provides support for local system logging (e.g. via logger command) $ModLoad imjournal # provides access to the systemd journal $WorkDirectory /var/lib/rsyslog $ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat $template myFormat,"%timestamp% %fromhost-ip% %msg%n" $IncludeConfig /etc/rsyslog.d/*.conf $OmitLocalLogging on $IMJournalStateFile imjournal.state *.info;mail.none;authpriv.none;cron.none @192.168.99.99:514 *.info;mail.none;authpriv.none;cron.none /var/log/messages authpriv.* /var/log/secure mail.* -/var/log/maillog cron.* /var/log/cron *.emerg :omusrmsg:* uucp,news.crit /var/log/spooler local7.* /var/log/boot.log local0.* /etc/keepalived/keepalived.log
