Nagios监控nginx服务具体过程

1在nginx 服务器上安装nrpe客户端：

Nginx的服务须要监控起来。不然万一down了而不及时修复，会影响web应用。例如以下web应用上面启动的nginx后台进程
[root@lb-net-2 ~]# ps aux|grep nginx
nobody   15294  0.0  0.0  22432  3464 ?        S    Jul03   0:05 nginx: worker process      
nobody   15295  0.0  0.0  22432  3480 ?        S    Jul03   0:05 nginx: worker process      
......      
nobody   15316  0.0  0.0  22432  3468 ?

       S    Jul03   0:05 nginx: worker process      
nobody   15317  0.0  0.0  22432  3480 ?        S    Jul03   0:05 nginx: worker process      
root     16260  0.0  0.0  20584  1684 ?        Ss   Jun18   0:00 nginx: master process /usr/local/nginx/sbin/nginx
root     21211  0.0  0.0 103252   860 pts/1    S+   17:50   0:00 grep nginx

1.1，rpm方式安装nrpe客户端

下载地址：http://download.csdn.net/detail/mchdba/7493875

[root@localhost nagios]# ll

总计 768

-rw-r--r-- 1 root root 713389 12-16 12:08 nagios-plugins-1.4.11-1.x86_64.rpm

-rw-r--r-- 1 root root  32706 12-16 12:09 nrpe-2.12-1.x86_64.rpm

-rw-r--r-- 1 root root  18997 12-16 12:08 nrpe-plugin-2.12-1.x86_64.rpm

[root@localhost nagios]# rpm -ivh *.rpm --nodeps  --force

1.2 在配置文件最末尾，加入配置信息以及监控主机服务器ip地址

[root@ localhost nagios]# vim /etc/nagios/nrpe.cfg

# add by tim on 2014-06-11

command[check_users]=/usr/local/nagios/libexec/check_users -w 8 -c 15

command[check_load]=/usr/local/nagios/libexec/check_load -w 15,10,5 -c 30,25,20

command[check_sda1]=/usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /dev/sda

command[check_zombie_procs]=/usr/local/nagios/libexec/check_procs -w 5 -c 10 -s Z

#command[check_total_procs]=/usr/local/nagios/libexec/check_procs -w 50 -c 80

command[check_total_procs]=/usr/local/nagios/libexec/check_procs -w 750 -c 800

command[check-host-alive]=/usr/local/nagios/libexec/check_ping -H 10.xx.3.29 -w 3000.0,80% -c 5000.0,100% -p 5

allowed_hosts = 127.0.0.1,10.xx.3.41

check下命令是否生效：

[root@web-9 nrpe-2.15]# /usr/local/nagios/libexec/check_users -w 8 -c 15

USERS OK - 2 users currently logged in |users=2;8;15;0

[root@web-9 nrpe-2.15]#

看到已经USERS OK -….命令已经生效。

1.3 启动nrpe报错例如以下：

[root@web-9 ~]# service nrpe restart

Shutting down nrpe:                                        [失败]

Starting nrpe: /usr/sbin/nrpe: error while loading shared libraries: libssl.so.6: cannot open shared object file: No such file or directory

                                                           [失败]

[root@web-9 ~]#

[root@db-m2-slave-1 nagios_client]# service nrpe start

Starting nrpe: /usr/sbin/nrpe: error while loading shared libraries: libssl.so.6: cannot open shared object file: No such file or directory

                                                           [失败]

[root@db-m2-slave-1 nagios_client]#

建立连接

[root@db-m2-slave-1 nagios_client]# ln -s /usr/lib64/libssl.so /usr/lib64/libssl.so.6

 (假设没有libssl.so，就採用别的libssl.so.10来做软连接，ln -s /usr/lib64/libssl.so.10 /usr/lib64/libssl.so.6)

[root@db-m2-slave-1 nagios_client]#

再又一次启动例如以下：

[root@db-m2-slave-1 nagios_client]# service nrpe start

Starting nrpe: /usr/sbin/nrpe: error while loading shared libraries: libcrypto.so.6: cannot open shared object file: No such file or directory

                                                           [失败]

[root@web-10 ~]# ll /usr/lib64/libcrypto.so

lrwxrwxrwx. 1 root root 18 10月 13 2013 /usr/lib64/libcrypto.so -> libcrypto.so.1.0.0

[root@db-m2-slave-1 nagios_client]#

再建链接：
[root@db-m2-slave-1 nagios_client]# ln -s /usr/lib64/libcrypto.so /usr/lib64/libcrypto.so.6

(或者假设没有libcrypto.so，就採用libcrypto.so.10做软连接， ln -s /usr/lib64/libcrypto.so.10 /usr/lib64/libcrypto.so.6)

[root@db-m2-slave-1 nagios_client]# service nrpe start

Starting nrpe:                                             [确定]

[root@db-m2-slave-1 nagios_client]#

1.4 检測下nrpe是否正常执行：

去nagios服务器端check下

[root@cache-2 ~]#  /usr/local/nagios/libexec/check_nrpe -H 10.xx.3.xx

NRPE v2.12

[root@cache-2 ~]#

看到返回NRPE v2.15表示已经连接成功，客户端的nrpe服务已经监控完毕。

2，比較简单的通过check_http的方式监控

能够在/etc/nagios/nrpe.cfg里面採用check_http的方式来获取nginx是否执行：

(1)     编辑nrpe.cfg

Vim /etc/nagios/nrpe.cfg

command[check_nginx_status]=/usr/lib/nagios/plugins/check_http -I localhost -p 80 -u /nginx_status -e 200 -w 3 -c 10

(2)     重新启动nrpe服务

[root@lb-net-2 ~]# service nrpe restart

Shutting down nrpe:                                        [确定]

Starting nrpe:                                             [确定]

[root@lb-net-2 ~]#

(3)     在nagios服务器端check。成功。

[root@cache-2 ~]# /usr/local/nagios/libexec/check_nrpe -H10.xx.1.22 -c check_nginx_status

HTTP OK HTTP/1.1 200 OK - 254 bytes in 0.002 seconds |time=0.002031s;3.000000;10.000000;0.000000 size=254B;;;0

(4)     在services.cfg里面加入check_nginx_status服务

define service{

        host_name               lb-net-2

        service_description     check_nginx_status

        check_command           check_nrpe!check_nginx_status

        max_check_attempts      5

        normal_check_interval   3

        retry_check_interval    2

        check_period            24x7

        notification_interval   10

        notification_period     24x7

        notification_options    w,u,c,r

        contact_groups          opsweb

        }

(5)     在command.cfg加入check_nginx_status服务

define command{

        command_name    check_nginx_status

        command_line    $USER1$/check_nginx_status -I $HOSTADDRESS$ -w $Warning$ -c $Cri$

        }

(6)     又一次载入nagios

[root@cache-2 objects]# service nagios reload

Running configuration check...

Reloading nagios configuration...

done

[root@cache-2 objects]#

(7)     查看界面的nginx监控服务。例如以下所看到的：

3 编写脚本来监控nginx服务

3.1 调试具体经过

[root@lb-net-2 run]# find / -name nginx.pid

/usr/local/nginx/logs/nginx.pid

[root@lb-net-2 run]# /usr/lib/nagios/plugins/check_nginxstatus -H localhost -P 80 -p /usr/local/nginx/logs/ -n /usr/local/nginx/logs/nginx.pid -s nginx_status -o /tmp/ -w 1500 -c 2000

expr: 參数数目错误

expr: 语法错误

(standard_in) 1: syntax error

/usr/lib/nagios/plugins/check_nginxstatus: line 258: [: : integer expression expected

/usr/lib/nagios/plugins/check_nginxstatus: line 262: [: : integer expression expected

OK - nginx is running.  requests per second,  connections per second ( requests per connection) | 'reqpsec'= 'conpsec'= 'conpreq'= ]

去查看262行。将逻辑运算符  "-a" 改成 "&&"

[root@lb-net-2 run]# vim /usr/lib/nagios/plugins/check_nginxstatus

[root@lb-net-2 run]# /usr/lib/nagios/plugins/check_nginxstatus -H localhost -P 80 -p /usr/local/nginx/logs/ -n /usr/local/nginx/logs/nginx.pid -s nginx_status -o /tmp/ -w 1500 -c 2000

expr: 參数数目错误

expr: 语法错误

(standard_in) 1: syntax error

/usr/lib/nagios/plugins/check_nginxstatus: line 258: [: missing `]'

/usr/lib/nagios/plugins/check_nginxstatus: line 262: [: : integer expression expected

OK - nginx is running.  requests per second,  connections per second ( requests per connection) | 'reqpsec'= 'conpsec'= 'conpreq'= ]

[root@lb-net-2 run]#

看到已经OK了。再改动文件。

[root@lb-net-2 run]# vim /usr/lib/nagios/plugins/check_nginxstatus

[root@lb-net-2 run]#

[root@lb-net-2 run]# /usr/lib/nagios/plugins/check_nginxstatus -H localhost -P 80 -p /usr/local/nginx/logs/ -n /usr/local/nginx/logs/nginx.pid -s nginx_status -o /tmp/ -w 1500 -c 2000

expr: 參数数目错误

expr: 语法错误

(standard_in) 1: syntax error

/usr/lib/nagios/plugins/check_nginxstatus: line 258: [: missing `]'

OK - nginx is running.  requests per second,  connections per second ( requests per connection) | 'reqpsec'= 'conpsec'= 'conpreq'= ]

[root@lb-net-2 run]#

将[]改成使用"[[]]"。 就可以！

[root@lb-net-2 run]# vim /usr/lib/nagios/plugins/check_nginxstatus

[root@lb-net-2 run]#

[root@lb-net-2 run]#

[root@lb-net-2 run]# /usr/lib/nagios/plugins/check_nginxstatus -H localhost -P 80 -p /usr/local/nginx/logs/ -n /usr/local/nginx/logs/nginx.pid -s nginx_status -o /tmp/ -w 1500 -c 2000

expr: 參数数目错误

expr: 语法错误

(standard_in) 1: syntax error

OK - nginx is running.  requests per second,  connections per second ( requests per connection) | 'reqpsec'= 'conpsec'= 'conpreq'= ]

[root@lb-net-2 run]#

凝视掉#reqpcon=`echo "scale=2; $reqpsec / $conpsec" | bc -l`之后。就不会报(standard_in) 1: syntax error错误，例如以下所看到的：

[root@lb-net-2 run]# /usr/lib/nagios/plugins/check_nginxstatus -H localhost -P 80 -p /usr/local/nginx/logs/ -s nginx_status -n nginx.pid -w 15000 -c 20000

expr: 參数数目错误

expr: 语法错误

OK - nginx is running.  requests per second,  connections per second ( requests per connection) | 'reqpsec'= 'conpsec'= 'conpreq'= ]

[root@lb-net-2 run]#

凝视掉# reqpsec=`expr $tmp2_reqpsec - $tmp1_reqpsec` 就不会再报 expr: 參数数目错误，例如以下所看到的：

报错：

[root@lb-net-2 run]# /usr/lib/nagios/plugins/check_nginxstatus -H localhost -P 80 -p /usr/local/nginx/logs/ -s nginx_status -n nginx.pid -w 15000 -c 20000

expr: 语法错误

OK - nginx is running.  requests per second,  connections per second ( requests per connection) | 'reqpsec'= 'conpsec'= 'conpreq'= ]

再次凝视掉 #reqpcon=`echo "scale=2; $reqpsec / $conpsec" | bc -l` 后。执行不会报expr: 语法错误。例如以下所看到的：

[root@lb-net-2 run]# /usr/lib/nagios/plugins/check_nginxstatus -H localhost -P 80 -p /usr/local/nginx/logs/ -s nginx_status -n nginx.pid -w 15000 -c 20000

OK - nginx is running.  requests per second,  connections per second ( requests per connection) | 'reqpsec'= 'conpsec'= 'conpreq'= ]

[root@lb-net-2 run]#

看到这里发现'reqpsec'= 'conpsec'= 'conpreq'=都没有值，可是nginx又是在启动执行着，问题出在哪里？经过排查，原来是nginx_status服务没有启动。须要在/usr/local/nginx/conf/nginx.conf配置文件中面加入例如以下配置：

# 加入pid參数

pid        logs/nginx.pid;

#charset koi8-r;

        access_log  logs/host.access.log  main;

        location /nginx_status {

                stub_status on;

                access_log   off;

                                     deny all;

         }

然后又一次载入nginx，看到新的nginx-status文件是生成了。可是文件内容为空，例如以下所看到的：

[root@lb-net-2 logs]# ll /tmp/nginx*

-rw-r--r--. 1 root root 0 7月   3 15:06 /tmp/nginx-status.1

[root@lb-net-2 logs]#

去查看ngins后台日志

[root@lb-net-2 logs]# cd /usr/local/nginx/

[root@lb-net-2 logs]# tail -n 300 error.log

……

2014/07/03 15:05:47 [error] 4285#0: *1851293 access forbidden by rule, client: 127.0.0.1, server: localhost, request: "GET /nginx_status HTTP/1.0", host: "localhost"

2014/07/03 15:05:48 [error] 4285#0: *1851294 access forbidden by rule, client: 127.0.0.1, server: localhost, request: "GET /nginx_status HTTP/1.0", host: "localhost"

2014/07/03 15:06:12 [error] 4282#0: *1851362 access forbidden by rule, client: 127.0.0.1, server: localhost, request: "GET /nginx_status HTTP/1.0", host: "localhost"

2014/07/03 15:06:13 [error] 4282#0: *1851363 access forbidden by rule, client: 127.0.0.1, server: localhost, request: "GET /nginx_status HTTP/1.0", host: "localhost"

2014/07/03 15:06:55 [error] 4285#0: *1851509 access forbidden by rule, client: 127.0.0.1, server: localhost, request: "GET /nginx_status HTTP/1.0", host: "localhost"

2014/07/03 15:06:56 [error] 4285#0: *1851519 access forbidden by rule, client: 127.0.0.1, server: localhost, request: "GET /nginx_status HTTP/1.0", host: "localhost"

查看nginx编译參数

[root@lb-net-2 logs]# /usr/local/nginx/sbin/nginx -V

nginx version: nginx/1.4.2

built by gcc 4.4.7 20120313 (Red Hat 4.4.7-3) (GCC)

configure arguments: --prefix=/usr/local/nginx --with-http_stub_status_module --with-http_realip_module

证明白实是载入了stub_status插件，之后去改动配置文件。凝视掉deny all;又一次载入nginx。

[root@lb-net-2 logs]# vim /usr/local/nginx/conf/nginx.conf

#deny all;

[root@lb-net-2 logs]# service nginx reload

reload nginx

[root@lb-net-2 logs]#

[root@lb-net-2 logs]# ll /tmp/nginx*

ls: 无法訪问/tmp/nginx*: 没有那个文件或文件夹

[root@lb-net-2 logs]#

还是没有看到/tmp/nginx-status.1状态文件生成。因为nagios下监控nginx的脚本是从nginx-status.1获取数据，假设没有这个文件，没有办法获取数据。

继续google，”nginx stub_status没有生成nginx-status.1”文件。看到有人说仅仅要配置好了这个状态文件有没有无所谓，我就试着直接执行脚本看看是否能生效。

[root@lb-net-2 logs]# ll /tmp/nginx*

ls: 无法訪问/tmp/nginx*: 没有那个文件或文件夹

[root@lb-net-2 logs]# /root/check_nginx2.sh  -H localhost -P 80 -p /usr/local/nginx/logs/ -n nginx.pid -s nginx_status -w 15000 -c 20000

OK - nginx is running. 1 requests per second, 2 connections per second (.50 requests per connection) | 'reqpsec'=1 'conpsec'=2 'conpreq'=.50 ]

[root@lb-net-2 logs]#

看到'reqpsec'=1 'conpsec'=2 'conpreq'=.50里面有数据了，再去check下文件有没有生成，例如以下所看到的：

[root@lb-net-2 logs]# ll /tmp/nginx*

ls: 无法訪问/tmp/nginx*: 没有那个文件或文件夹

[root@lb-net-2 logs]#

还是没有文件生成，可是check已经有数据了，证明不一定要拘泥于是否在/tmp/文件夹下是否有nginx-status.1文件。

通过脚本分析例如以下：

[root@lb-net-2 logs]# vim /usr/lib/nagios/plugins/check_nginxstatus

180 get_status() {

181     if [ "$secure" = 1 ]

182     then

183         wget_opts="-O- -q -t 3 -T 3 --no-check-certificate"

184         out1=`wget ${wget_opts} http://${hostname}:${port}/${status_page}`

185         sleep 1

186         out2=`wget ${wget_opts} http://${hostname}:${port}/${status_page}`

187     else

188         wget_opts="-O- -q -t 3 -T 3"

189         out1=`wget ${wget_opts} http://${hostname}:${port}/${status_page}`

190         sleep 1

191         out2=`wget ${wget_opts} http://${hostname}:${port}/${status_page}`

192     fi

193

194     if [ -z "$out1" -o -z "$out2" ]

195     then

196         echo "UNKNOWN - Local copy/copies of $status_page is empty."

197         exit $ST_UK

198     fi

199 }

是通过訪问`wget -O- -q -t 3 -T 3 --no-check-certificate http://10.xx.xx.xx:80/nginx_status`这个链接来获取status的数据记录的，而不是去载入/tmp/nginx-status.1文件来获取数据的。

直接訪问 http://10.xx.xx.xx:80/nginx_status 地址就能获取nginx执行数据，例如以下图所看到的：

在nagios服务器上check下。报错：

[root@cache-2 ~]# /usr/local/nagios/libexec/check_nrpe -H10.xx.xx.xx -c check_nginx_status

UNKNOWN - Local copy/copies of nginx_status is empty.

[root@cache-2 ~]#

检查监控脚本，搜索 ‘Local copy/copies of nginx_status is empty.’在第197行，有例如以下代码：

195     if [ -z "$out1" -o -z "$out2" ]

196     then

197         echo "UNKNOWN - Local copy/copies of $status_page is empty."

198         exit $ST_UK

199     fi

看出是因为if [ -z "$out1" -o -z "$out2" ]这个推断生效。导致监控脚本执行到这里就exit了。继续调试。发现用nagios服务器调用脚本的时候。执行到下面第190行到第192行

out1=`/usr/bin/wget ${wget_opts} http://${hostname}:${port}/${status_page}`

        sleep 1

        out2=`/usr/bin/wget ${wget_opts} http://${hostname}:${port}/${status_page}`

的时候。out1为空，out2也为空，所以在后面的if [ -z "$out1" -o -z "$out2" ]推断通过报出信息为：UNKNOWN - Local copy/copies of $status_page is empty. 然后直接exit。

说明：因为nginx是要调用wget命令来获取nginx_status状态的，而wget命令是仅仅能以root用户来执行的, 所以须要将nagios用户设置成能够无需password直接su成root，这样就能以nagios用户执行命令sudo /usr/lib/nagios/plugins/check_nginxstatus 。在centos系统中。无法直接调用sudo命令，须要改动/etc/sudoers, 找到 #Defaults requiretty 并取消凝视，另外新增一行。表示nagios用户不须要登陆终端就能够调用命令。例如以下所看到的：

Defaults    requiretty

Defaults:nagios    !requiretty

#加入nagios 请求sudo，同意特定指令时（可跟參数），不须要password（如）。

nagios ALL=(ALL) NOPASSWD: ALL

改动完后。再check，数据出来了：

[root@cache-2 ~]# /usr/local/nagios/libexec/check_nrpe -H10.xx.xx.xx -c check_nginx_status

OK - nginx is running. 1 requests per second, 1 connections per second (1.00 requests per connection) | 'reqpsec'=1 'conpsec'=1 'conpreq'=1.00 ]

[root@cache-2 ~]#

3.2  share下check_nginxstatus脚本