rsyslog 可以理解为多线程增强版的syslog。 在syslog的基础上扩展了很多其他功能,如数据库支持(MySQL、PostgreSQL、Oracle等)、日志内容筛选、定义日志格式模板等。目前大多数Linux发行版默认也是使用rsyslog进行日志记录。rsyslog提供了三种远程传输协议:

UDP 传输协议 
基于传统UDP协议进行远程日志传输,也是传统syslog使用的传输协议; 可靠性比较低,但性能损耗最少, 在网络情况比较差, 或者接收服务器压力比较高情况下,
可能存在丢日志情况。 在对日志完整性要求不是很高,在可靠的局域网环境下可以使用。

TCP 传输协议 
基于传统TCP协议明文传输,需要回传进行确认,可靠性比较高; 但在接收服务器宕机或者两者之间网络出问题的情况下,会出现丢日志情况。 这种协议相比于UDP在
可靠性方面已经好很多,并且rsyslog原生支持,配置简单, 同时针对可能丢日志情况,可以进行额外配置提高可靠性,因此使用比较广。

RELP 传输协议 
RELP(Reliable Event Logging Protocol)是基于TCP封装的可靠日志消息传输协议; 是为了解决TCP 与 UDP 协议的缺点而在应用层实现的传输协议,也是三者
之中最可靠的。 需要多安装一个包rsyslog-relp以支持该协议。

对于线上服务器,为了日志安全起见,建议使用还是使用 RELP 协议进行传输。

rsyslog的简单配置记录(如下将公司防火墙上的日志(UDP)打到IDC的rsyslog日志服务器上)

一、rsyslog服务端的部署
安装rsyslog 程序(rsyslog默认已经在各发行版安装,如果系统中没有的话,可以用yum 进行安装,如下:)
[root@zabbix ~]# yum install rsyslog -y

配置:
[root@zabbix ~]# cat /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                                          #开启udp的514端口。也可以开启tcp的514端口,这里只接受udp的
$UDPServerRun 514

# Provides TCP syslog reception
#$ModLoad imtcp
#$InputTCPServerRun 514

$WorkDirectory /var/lib/rsyslog
$AllowedSender udp, 192.168.17.0/8                    #仅仅接收来自192.168.17.0/8网段的主机的udp日志(这个是公司防火墙的ip地址)
#### GLOBAL DIRECTIVES ####

# Use default timestamp format
$ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat
$template Remote,"/data/fw_logs/%fromhost-ip%/%fromhost-ip%_%$YEAR%-%$MONTH%-%$DAY%.log"           #定义模板,接受日志文件路径,区分了不同主机的日志
:fromhost-ip, !isequal, "127.0.0.1" ?Remote                                                        # 过滤server 本机的日志
# 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.
#kern.*                                                 /dev/console

# Log anything (except mail) of level info or higher.
# Don't log private authentication messages!
*.info;mail.none;authpriv.none;cron.none                /var/log/messages

# The authpriv file has restricted access.
authpriv.*                                              /var/log/secure

# Log all the mail messages in one place.
mail.*                                                  -/var/log/maillog
local4.*                                                /data/fw.log

# Log cron stuff
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
local7.*                                                /var/log/boot.log


# ### 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
#*.* @@remote-host:514
# ### end of the forwarding rule ###


[root@zabbix ~]# mkdir /data/fw_logs/

[root@zabbix ~]# /etc/init.d/rsyslog restart


二、在公司防火墙(192.168.17.41/42)上配置udp日志输出策略(在防火墙添加rsyslog服务端的ip和514端口)

三、过一会儿,在rsyslog日志服务器上设置的日志目录下就能看到防火墙的日志输出了
[root@zabbix ~]# ll /data/fw_logs/
total 4.0K
drwxrwxrwx   4 root root   46 Jul 28 10:40 .
drwxr-xr-x. 18 root root 4.0K Jul 28 10:38 ..
drwx------   2 root root   41 Jul 28 10:37 192.168.17.41
drwx------   2 root root   41 Jul 28 10:40 192.168.17.42
[root@zabbix ~]# ll /data/fw_logs/192.168.17.41
total 16K
drwx------ 2 root root  41 Jul 28 10:37 .
drwxrwxrwx 4 root root  46 Jul 28 10:40 ..
-rw------- 1 root root 13K Jul 28 14:02 192.168.17.41_2017-07-28.log


------------------------------------------------------------------------------------
可以将上面rsyslog服务端的rsyslog.conf里的ip白名单设置为客户机的ip端,比如:
$AllowedSender tcp, 172.18.0.0/16                  #表示接收172.18.0.0/16网段的客户机的tcp日志输入,前提是打开tcp的514端口

客户机的配置:
只需要在rsyslog.conf文件里添加下面一行:
*.*                               @172.18.10.20                     #后面的ip是rsyslog服务端的ip地址

启动rsyslog日志即可!

====================再看一例=======================
以上配置的是将公司防火墙的日志打到rsyslog里。现在有这么一个需求:
公司IDC的另外两台服务器172.19.10.24和172.19.10.25上部署了gitlab、nexus、jenkins、jira和wiki,上面的权限设置的比较杂,很多人都有登录需求。现在需要将登录到这两台服务器上的用户的所有操作过程记录下来,记录达到rsyslog日志里,相当于做用户操作记录的审计工作。

配置如下(结合上面的安装配置)(服务端的ip是172.19.16.21):
1)rsyslog服务端配置  (相比于上面的配置,这里去掉了AllowedSender的来源ip的白名单限制。即允许接收所有机器的日志;上面的防火墙日志还是能继续收集)
[root@zabbix ~]# cat /etc/rsyslog.conf|grep -v "#"|grep -v "^$"
$ModLoad imudp
$UDPServerRun 514
$WorkDirectory /var/lib/rsyslog
$ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat
$template Remote,"/data/fw_logs/%fromhost-ip%/%fromhost-ip%_%$YEAR%-%$MONTH%-%$DAY%.log"
:fromhost-ip, !isequal, "127.0.0.1" ?Remote
$IncludeConfig /etc/rsyslog.d/*.conf
*.info;mail.none;authpriv.none;cron.none                /var/log/messages
authpriv.*                                              /var/log/secure
mail.*                                                  -/var/log/maillog
cron.*                                                  /var/log/cron
*.emerg                                                 *
uucp,news.crit                                          /var/log/spooler
local7.*                                                /var/log/boot.log
local5.*                                              /var/log/history.log

[root@zabbix ~]# /etc/init.d/rsyslog restart

2)在172.19.10.24上的配置
[root@gitlab ~]# cat /etc/rsyslog.conf|grep -v "#"|grep -v "^$"
$ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat
$IncludeConfig /etc/rsyslog.d/*.conf
*.info;mail.none;authpriv.none;cron.none                /var/log/messages
authpriv.*                                              /var/log/secure
mail.*                                                  -/var/log/maillog
cron.*                                                  /var/log/cron
*.emerg                                                 *
uucp,news.crit                                          /var/log/spooler
local7.*                                                /var/log/boot.log
local5.*    @172.19.16.21

[root@gitlab ~]# /etc/init.d/rsyslog restart

[root@gitlab ~]# cat /etc/profile                  #在该文件的底部添加下面内容
.......
export HISTTIMEFORMAT
export PROMPT_COMMAND='{ command=$(history 1 | { read x y; echo $y; }); logger -p local5.notice -t bash -i "user=$USER,ppid=$PPID,from=$SSH_CLIENT,pwd=$PWD,command:$command"; }'

3)在另一台172.19.10.25上做类似配置配置
[root@nexus ~]# cat /etc/rsyslog.conf |grep -v "#"|grep -v "^$"
$ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat
$IncludeConfig /etc/rsyslog.d/*.conf
*.info;mail.none;authpriv.none;cron.none                /var/log/messages
authpriv.*                                              /var/log/secure
mail.*                                                  -/var/log/maillog
cron.*                                                  /var/log/cron
*.emerg                                                 *
uucp,news.crit                                          /var/log/spooler
local7.*                                                /var/log/boot.log
local5.*   @172.19.16.21 

[root@nexus ~]# /etc/init.d/rsyslog restart

[root@nexus ~]# cat /etc/profile
.......
export HISTTIMEFORMAT
export PROMPT_COMMAND='{ command=$(history 1 | { read x y; echo $y; }); logger -p local5.notice -t bash -i "user=$USER,ppid=$PPID,from=$SSH_CLIENT,pwd=$PWD,command:$command"; }'

4)过一段时间,发现在rsyslog服务端的日志目录/data/fw_logs下面已经有收集到的日志了
[root@zabbix fw_logs]# pwd
/data/fw_logs
[root@zabbix fw_logs]# cd
[root@zabbix ~]# cd /data/fw_logs/
[root@zabbix fw_logs]# ll
total 12K
drwxrwxrwx   6 root root   84 Aug 16 18:28 .
drwxr-xr-x. 18 root root 4.0K Aug 16 17:58 ..
drwx------   2 root root   74 Aug 17 09:50 172.19.10.24
drwx------   2 root root   74 Aug 17 10:00 172.19.10.25
drwx------   2 root root 4.0K Aug 17 00:01 192.168.17.41
drwx------   2 root root 4.0K Aug 17 00:01 192.168.17.42
[root@zabbix fw_logs]# cd 172.19.10.24/
[root@zabbix 172.19.10.24]# ll
total 20K
drwx------ 2 root root  74 Aug 17 09:50 .
drwxrwxrwx 6 root root  84 Aug 16 18:28 ..
-rw------- 1 root root 14K Aug 16 20:45 172.19.10.24_2017-08-16.log
-rw------- 1 root root 771 Aug 17 10:03 172.19.10.24_2017-08-17.log
[root@zabbix 172.19.10.24]# cat 172.19.10.24_2017-08-16.log
Aug 16 18:39:56 gitlab bash[138413]: user=root,ppid=124297,from=172.19.16.28 29338 22,pwd=/root,command:[2017-08-16 18:39:56]root pts/5 2017-08-16 17:23 (172.19.16.28)/etc/init.d/rsyslog restart
Aug 16 18:39:56 gitlab bash[138418]: user=root,ppid=124297,from=172.19.16.28 29338 22,pwd=/root,command:[2017-08-16 18:39:56]root pts/5 2017-08-16 17:23 (172.19.16.28)/etc/init.d/rsyslog restart
Aug 16 18:39:56 gitlab bash[138422]: user=root,ppid=124297,from=172.19.16.28 29338 22,pwd=/root,command:[2017-08-16 18:39:56]root pts/5 2017-08-16 17:23 (172.19.16.28)/etc/init.d/rsyslog restart
Aug 16 18:39:57 gitlab bash[138426]: user=root,ppid=124297,from=172.19.16.28 29338 22,pwd=/root,command:[2017-08-16 18:39:56]root pts/5 2017-08-16 17:23 (172.19.16.28)/etc/init.d/rsyslog restart
Aug 16 18:40:30 gitlab bash[138610]: user=root,ppid=138586,from=172.16.255.202 52496 22,pwd=/root,command:[2017-08-16 18:40:03]root pts/0 2017-08-16 18:40 (172.16.255.202)exit
Aug 16 18:40:43 gitlab bash[138652]: user=root,ppid=138586,from=172.16.255.202 52496 22,pwd=/data,command:[2017-08-16 18:40:43]root pts/0 2017-08-16 18:40 (172.16.255.202)cd /data/
Aug 16 18:40:43 gitlab bash[138657]: user=root,ppid=138586,from=172.16.255.202 52496 22,pwd=/data,command:[2017-08-16 18:40:43]root pts/0 2017-08-16 18:40 (172.16.255.202)ls
Aug 16 18:40:47 gitlab bash[138666]: user=root,ppid=138586,from=172.16.255.202 52496 22,pwd=/data,command:[2017-08-16 18:40:47]root pts/0 2017-08-16 18:40 (172.16.255.202)mkdir hahahahah
Aug 16 18:40:48 gitlab bash[138671]: user=root,ppid=138586,from=172.16.255.202 52496 22,pwd=/data/hahahahah,command:[2017-08-16 18:40:48]root pts/0 2017-08-16 18:40 (172.16.255.202)cd hahahahah/
Aug 16 18:40:48 gitlab bash[138677]: user=root,ppid=138586,from=172.16.255.202 52496 22,pwd=/data/hahahahah,command:[2017-08-16 18:40:48]root pts/0 2017-08-16 18:40 (172.16.255.202)ls
Aug 16 18:40:54 gitlab bash[138696]: user=root,ppid=138586,from=172.16.255.202 52496 22,pwd=/data/hahahahah,command:[2017-08-16 18:40:54]root pts/0 2017-08-16 18:40 (172.16.255.202)echo "Asdfasdf" >heihei
Aug 16 18:40:54 gitlab bash[138702]: user=root,ppid=138586,from=172.16.255.202 52496 22,pwd=/data/hahahahah,command:[2017-08-16 18:40:54]root pts/0 2017-08-16 18:40 (172.16.255.202)ls
.......

有上面日志可以看出,在172.19.10.24这台机器上的操作记录都被详细记录下来了。这样,就能清楚地知道登录到这台机器上的用户都做了些什么了.......

=====================通过rsyslog收集nginx日志到远程服务器上====================
需求说明:通过rsyslog服务将192.168.10.21服务器上的/data/nginx/logs/www.kevin.com-access.log日志实时同步到192.168.10.52服务器上(路径为/data/rsyslog/nginx)。

1)192.168.10.21为rsyslog客户端,即日志的推送端。rsyslog日志是客户机主动将自己的日志推送到远程服务器上。
操作如下:
[root@nginx-server ~]# yum install rsyslog -y
[root@nginx-server ~]# cp /etc/rsyslog.conf /etc/rsyslog.conf.bak
[root@nginx-server ~]# cat /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
$ModLoad imfile                               ##装载imfile模块,这一行手动添加

# 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.
#kern.*                                                 /dev/console

# Log anything (except mail) of level info or higher.
# Don't log private authentication messages!
*.info;mail.none;authpriv.none;cron.none;local5.none                /var/log/messages             ##不记录local5的日志

# The authpriv file has restricted access.
authpriv.*                                              /var/log/secure

# Log all the mail messages in one place.
mail.*                                                  -/var/log/maillog


# Log cron stuff
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
local7.*                                                /var/log/boot.log


# ### 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
#*.* @@remote-host:514
# ### end of the forwarding rule ###
user.info /var/log/history

#在文件底部添加下面几行内容
$InputFileName /data/nginx/logs/www.kevin.com-access.log        ##读取日志文件(要监控的日志文件)
$InputFileTag web_access             ##日志写入日志附加标签字符串
$InputFileSeverity info           ##日志等级
$InputFileStateFile /etc/rsyslog.d/stat-access         ##记录日志点等信息。(相当于msyql的master.info)文件名变了,
                                                这个StateFile标志必须变,否则无法传输。
$InputFileFacility local5         ##设施类别
$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。
local5.*  @192.168.10.52            ##代表local5设施的所有级别通过udp协议传送到192.168.10.51

重启rsyslog服务
[root@nginx-server ~]# /etc/init.d/rsyslog restart
关闭系统日志记录器:                                       [确定]
启动系统日志记录器:                                       [确定]

由于作为日志的推送端,rsyslog日志不需要开启514端口(如上在rsyslog.conf文件里没有打开dup或tcp的514端口)
[root@nginx-server ~]# lsof -i:514
[root@nginx-server ~]#

2)192.168.10.52为rsyslog服务端,即日志的接收端。
配置如下:
[root@log-server ~]# yum install rsyslog -y
[root@log-server ~]# cp /etc/rsyslog.conf /etc/rsyslog.conf.bak
# rsyslog 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 ####

# The imjournal module bellow is now used as a message source instead of imuxsock.
$ModLoad imuxsock # provides support for local system logging (e.g. via logger command)
$ModLoad imjournal # provides access to the systemd journal
#$ModLoad imklog # reads kernel messages (the same are read from journald)
#$ModLoad immark  # provides --MARK-- message capability

# Provides UDP syslog reception
$ModLoad imudp                   ##载入imudp模块
$UDPServerRun 514            ##开启udp接收并制定端口号

# Provides TCP syslog reception
$ModLoad imtcp                 ##载入imtcp模块。
$InputTCPServerRun 514             ##开启tcp接收并制定端口号。tcp和udp两个端口模块可以同时使用!

#### GLOBAL DIRECTIVES ####

# Where to place auxiliary files
$WorkDirectory /var/lib/rsyslog

# Use default timestamp format
$ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat

#定义一个模板用来指定接收的日志消息的格式(默认会在记录的日志前加几个字段)
$template  SpiceTmpl,"%msg%\n"                   ##%msg:2:$%为去掉日志开头的空格

#定义一个模板用来指定接收的日志文件的存放路径%……%之间的是定义日志按照年-月-日命名
$template  DynaFile,"/data/rsyslog/nginx/%$YEAR%-%$MONTH%-%$DAY%.log"

# 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

# Turn off message reception via local log socket;
# local messages are retrieved through imjournal now.
$OmitLocalLogging on

# File to store the position in the journal
$IMJournalStateFile imjournal.state


#### RULES ####

# Log all kernel messages to the console.
# Logging much else clutters up the screen.
#kern.*                                                 /dev/console

# Log anything (except mail) of level info or higher.
# Don't log private authentication messages!
*.info;mail.none;authpriv.none;cron.none;local5.none                /var/log/messages            ##不记录local5设施的日志

# The authpriv file has restricted access.
authpriv.*                                              /var/log/secure

# Log all the mail messages in one place.
mail.*                                                  -/var/log/maillog


# Log cron stuff
cron.*                                                  /var/log/cron

# Everybody gets emergency messages
*.emerg                                                 :omusrmsg:*

# 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
local7.*                                                /var/log/boot.log

#接收客户端local5设施传送来的日志并存放到指定位置(位置可用定义的模板。?代表使用动态的模板)
local5.*                       ?DynaFile;SpiceTmpl

# ### 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.
#$ActionQueueFileName fwdRule1 # unique name prefix for spool files
#$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
#*.* @@remote-host:514
# ### end of the forwarding rule ###

编辑/etc/sysconfig/rsyslog中"SYSLOGD_OPTIONS="开启远程日志接收功能
[root@log-server ~]# cat /etc/sysconfig/rsyslog
# Options for rsyslogd
# Syslogd options are deprecated since rsyslog v3.
# If you want to use them, switch to compatibility mode 2 by "-c 2"
# See rsyslogd(8) for more details
SYSLOGD_OPTIONS="-c 5"

创建日志接收过来后定义的存放目录
[root@log-server ~]# mkdir -p /data/rsyslog/nginx

重启rsyslog服务
[root@log-server ~]# /etc/init.d/rsyslog restart
Shutting down system logger:                               [  OK  ]
Starting system logger:                                    [  OK  ]
[root@log-server ~]# lsof -i:514
COMMAND    PID USER   FD   TYPE   DEVICE SIZE/OFF NODE NAME
rsyslogd 24594 root    2u  IPv4 38927639      0t0  TCP *:shell (LISTEN)
rsyslogd 24594 root    3u  IPv4 38927635      0t0  UDP *:syslog
rsyslogd 24594 root    4u  IPv6 38927636      0t0  UDP *:syslog
rsyslogd 24594 root    5u  IPv6 38927640      0t0  TCP *:shell (LISTEN)

查看日志是否接收过来了
[root@log-server ~]# ll /data/rsyslog/nginx/
total 550876
-rw------- 1 root root 483539594 Jun 13 12:58 2018-06-13.log
[root@log-server ~]# tail -2 /data/rsyslog/nginx/2018-06-13.log
1.203.163.198 - [27/Apr/2018:00:17:53 +0800] "POST /scf/%7B%7BloginConfig.loginSubmitUrl%7D%7D HTTP/1.1" 302 0 "https://www.kevin.com/scf/login" Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/29.0.1547.62 Safari/537.36 - 0.010 0.003 10.0.54.21:9020 302
1.203.163.198 - [27/Apr/2018:00:17:53 +0800] "POST /scf/%7B%7BloginConfig.loginSubmitUrl%7D%7D HTTP/1.1" 302 0 "https://www.kevin.com/scf/login" Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/29.0.1547.62 Safari/537.36 - 0.012 0.003 10.0.54.21:9020 302

=========================温馨提示========================
rsyslog也可以收集多个日志文件,需要注意的是:
$InputFileTag        定义的APPNAME必须唯一,同一台主机上不同的应用应当使用不同的APPNAME,否则会导致新定义的TOKEN和TAG不生效;
$template         定义的模板名必须唯一,否则会导致新定义的TOKEN和TAG不生效;
$InputFileStateFile       定义的StateFile必须唯一,它被rsyslog用于记录文件上传进度,否则会导致混乱;

如下是rsyslog收集多个日志的配置,这里以2个日志文件为例:

日志的推送端配置

[root@external-lb01 ~]# cat /etc/rsyslog.conf
..........
$ModLoad imfile

.........
*.info;mail.none;authpriv.none;cron.none;local5.none;local4.none                /var/log/messages

.........

$InputFileName /data/nginx/logs/portal.kevin.com-access.log
$InputFileTag portal_access
$InputFileSeverity info
$InputFileStateFile /etc/rsyslog.d/stat1-access
$InputFileFacility local4
$InputFilePollInterval 1
$InputFilePersistStateInterval 1
$InputRunFileMonitor 
local4.*  @192.168.10.52

$InputFileName /data/nginx/logs/www.kevin.com-access.log
$InputFileTag web_access
$InputFileSeverity info
$InputFileStateFile /etc/rsyslog.d/stat-access
$InputFileFacility local5
$InputFilePollInterval 1
$InputFilePersistStateInterval 1
$InputRunFileMonitor
local5.*  @192.168.10.52

重启日志发送端的rsyslog服务
[root@external-lb01 ~]# /etc/init.d/rsyslog restart

日志的接收端配置

[root@open-falcon01 ~]# cat /etc/rsyslog.conf
........
$ModLoad imudp
$UDPServerRun 514

# Provides TCP syslog reception
$ModLoad imtcp
$InputTCPServerRun 514

.........
$template SpiceTmpl,"%msg%\n" 
$template DynaFile,"/data/external-lb/nginx/nginx-access.log"

$template SpiceTmpl2,"%msg%\n" 
$template DynaFile2,"/data/external-lb/portal/portal-access.log"

.........
*.info;mail.none;authpriv.none;cron.none;local5.none;local4.none                /var/log/messages

.........
local5.*                                                ?DynaFile;SpiceTmpl
local4.*                                                ?DynaFile2;SpiceTmpl2

重启日志接收端的rsyslog服务
[root@open-falcon01 ~]# /etc/init.d/rsyslog restart

查看,当访问对应对应的url时,就会有转发后的文件产生,并实时有日志内容转发过来
[root@open-falcon01 ~]# ll /data/external-lb/nginx/nginx-access.log
-rw------- 1 root root 1067372 Oct  9 10:51 /data/external-lb/nginx/nginx-access.log
[root@open-falcon01 ~]# ll /data/external-lb/portal/portal-access.log 
-rw------- 1 root root 88141 Oct  9 22:26 /data/external-lb/portal/portal-access.log

==========================================================================
注意:
a)如果发现日志还没有接收过来,即/data/rsyslog/nginx目录下没有日志产生,就同时重启推送端和接收端的rsyslog服务。确保双方的iptables防火墙和selinux关闭!
b)也可以自行修改接收的日志文件的存放路径,如改为下面的配置:
$template  DynaFile,"/data/rsyslog/nginx/nginx-access.log"
则日志收集后存放的文件如下:
[root@log-server ~]# ll /data/rsyslog/nginx/
total 571716
-rw------- 1 root root 483539594 Jun 13 12:58 2018-06-13.log
-rw------- 1 root root 101893593 Jun 13 13:13 nginx-access.log