Nagios：NRPE：無法讀取輸出，找不到原因，可以嗎？

我有一個 Nagios 伺服器和一個受監控的伺服器。在受監控的伺服器上：

[root@Monitored ~]# netstat -an |grep :5666
tcp        0      0 0.0.0.0:5666                0.0.0.0:*                   LISTEN      
[root@Monitored ~]# locate check_kvm
/usr/lib64/nagios/plugins/check_kvm
[root@Monitored ~]# /usr/lib64/nagios/plugins/check_kvm -H localhost
hosts:3 OK:3 WARN:0 CRIT:0 - ab2c7:running alpweb5:running istaweb5:running
[root@Monitored ~]# /usr/lib64/nagios/plugins/check_nrpe -H localhost -c check_kvm
NRPE: Unable to read output
[root@Monitored ~]# /usr/lib64/nagios/plugins/check_nrpe -H localhost
NRPE v2.14
[root@Monitored ~]# ps -ef |grep nrpe
nagios   21178     1  0 16:11 ?        00:00:00 /usr/sbin/nrpe -c /etc/nagios/nrpe.cfg -d
[root@Monitored ~]#

在 Nagios 伺服器上：

[root@Nagios ~]# /usr/lib64/nagios/plugins/check_nrpe -H 1.1.1.159 -c check_kvm
NRPE: Unable to read output
[root@Nagios ~]# /usr/lib64/nagios/plugins/check_nrpe -H 1.1.1.159
NRPE v2.14
[root@Nagios ~]#

當我使用相同的命令檢查網路中的另一台伺服器時，它可以工作：

[root@Nagios ~]# /usr/lib64/nagios/plugins/check_nrpe -H 1.1.1.80 -c check_kvm
hosts:4 OK:4 WARN:0 CRIT:0 - karmisoft:running ab2c4:running kidumim1:running travel2gether1:running
[root@Nagios ~]#

使用 Nagios 帳戶在本地執行檢查：

[root@Monitored ~]# su - nagios
-bash-4.1$ /usr/lib64/nagios/plugins/check_kvm
hosts:3 OK:3 WARN:0 CRIT:0 - ab2c7:running alpweb5:running istaweb5:running
-bash-4.1$

使用 Nagios 帳戶從 Nagios 伺服器遠端執行檢查：

-bash-4.1$ /usr/lib64/nagios/plugins/check_nrpe -H 1.1.1.159 -c check_kvm
NRPE: Unable to read output
-bash-4.1$ /usr/lib64/nagios/plugins/check_nrpe -H 1.1.1.159
NRPE v2.14
-bash-4.1$

使用 Nagios 帳戶對網路中的不同伺服器執行相同的 check_kvm：

-bash-4.1$ /usr/lib64/nagios/plugins/check_nrpe -H 1.1.1.80 -c check_kvm
hosts:4 OK:4 WARN:0 CRIT:0 - karmisoft:running ab2c4:running kidumim1:running travel2gether1:running
-bash-4.1$ 

權限：

-rwxr-xr-x. 1 root root 4684 2013-10-14 17:14 nrpe.cfg (aka /etc/nagios/nrpe.cfg)
drwxrwxr-x. 3 nagios nagios 4096 2013-10-15 03:38 plugins (aka /usr/lib64/nagios/plugins)

/etc/sudoers:

[root@Monitored ~]# grep -i requiretty /etc/sudoers
#Defaults    requiretty

iptables/selinux：

[root@Monitored xinetd.d]# service iptables status
iptables: Firewall is not running.
[root@Monitored xinetd.d]# service ip6tables status
ip6tables: Firewall is not running.
[root@Monitored xinetd.d]# grep disable /etc/selinux/config 
#     disabled - No SELinux policy is loaded.
SELINUX=disabled
[root@Monitored xinetd.d]#

裡面的命令/etc/nagios/nrpe.cfg是：

[root@Monitored ~]# grep kvm /etc/nagios/nrpe.cfg 
command[check_kvm]=sudo /usr/lib64/nagios/plugins/check_kvm

並且nagios使用者被添加到/etc/sudoers：

nagios  ALL=(ALL) NOPASSWD:/usr/lib64/nagios/plugins/check_kvm
nagios  ALL=(ALL) NOPASSWD:/usr/lib64/nagios/plugins/check_nrpe

這check_kvm是一個shell腳本，看起來像這樣：

#!/bin/sh

LIST=$(virsh list --all | sed '1,2d' | sed '/^$/d'| awk '{print $2":"$3}')

if [ ! "$LIST" ]; then
 EXITVAL=3 #Status 3 = UNKNOWN (orange) 
 echo "Unknown guests"
 exit $EXITVAL
fi

OK=0
WARN=0
CRIT=0
NUM=0

for host in $(echo $LIST)
do
 name=$(echo $host | awk -F: '{print $1}')
 state=$(echo $host | awk -F: '{print $2}')
 NUM=$(expr $NUM + 1)

 case "$state" in
   running|blocked) OK=$(expr $OK + 1) ;;
   paused) WARN=$(expr $WARN + 1) ;;
   shutdown|shut*|crashed) CRIT=$(expr $CRIT + 1) ;;
   *) CRIT=$(expr $CRIT + 1) ;;
 esac
done

if [ "$NUM" -eq "$OK" ]; then
 EXITVAL=0 #Status 0 = OK (green)
fi

if [ "$WARN" -gt 0 ]; then
 EXITVAL=1 #Status 1 = WARNING (yellow)
fi

if [ "$CRIT" -gt 0 ]; then
 EXITVAL=2 #Status 2 = CRITICAL (red)
fi

echo hosts:$NUM OK:$OK WARN:$WARN CRIT:$CRIT - $LIST

exit $EXITVAL

編輯（2013 年 10 月 22 日）：在這一切之後，我現在可以從腳本中得到一些響應：

[root@Monitored ~]# /usr/lib64/nagios/plugins/check_nrpe -H localhost -c check_kvm
Unknown guests
[root@Monitored ~]# /usr/lib64/nagios/plugins/check_nrpe -H localhost
NRPE v2.14
[root@Monitored ~]# /usr/lib64/nagios/plugins/check_kvm
hosts:3 OK:3 WARN:0 CRIT:0 - ab2c7:running alpweb5:running istaweb5:running
[root@Monitored ~]# su - nagios
-bash-4.1$ /usr/lib64/nagios/plugins/check_kvm
hosts:3 OK:3 WARN:0 CRIT:0 - ab2c7:running alpweb5:running istaweb5:running
-bash-4.1$ /usr/lib64/nagios/plugins/check_nrpe -H localhost -c check_kvm
Unknown guests
-bash-4.1$ /usr/lib64/nagios/plugins/check_nrpe -H localhost
NRPE v2.14

似乎問題與check_nrpe命令有關，或者與nrpe伺服器上的安裝有關。

2013 年 12 月 2 日編輯：對有問題的伺服器工作的其他檢查：

好詳細的書面Itai！您是否嘗試過降低配置的複雜性以查看它是否有效？

對於初學者，我首先將行更改nrpe.cfg為

command[check_kvm]=/usr/lib64/nagios/plugins/check_kvm

並臨時將 /usr/lib64/nagios/plugins/check_kvm 腳本更改為非常簡單的內容，例如：

#!/bin/sh
echo Hi
exit 0

如果這行得通，那麼您可以開始增加複雜性。也許不是讓nagios使用者 sudo 訪問腳本，它確實需要訪問virsh命令，您可以省略命令行sudo中的部分。nrpe.cfg

引用自：https://serverfault.com/questions/546410