自己写了一个perl脚本检测redis(nagios插件)

放在我的code库内了，http://farmerluo.googlecode.com/files/check_redis.pl

介绍下怎么安装：

脚本用到了perl的Redis库，需要先安装这个：
# perl -MCPAN -e shell
# install Redis

wget http://farmerluo.googlecode.com/files/check_redis.pl

cp check_redis.pl  /etc/nagios/command/

chown cacti.nagios check_redis.pl

在nagios内加入这个插件：
vi /etc/nagios/objects/command.cfg

# 'check_redis' command definition
define command{
command_name    check_redis
command_line    /etc/nagios/command/check_redis.pl -h $HOSTADDRESS$ $ARG1$
}


加入一个服务：
vi /etc/nagios/objects/linuxhost.cfg

define service{
use                             generic-service         ; Name of service template to use
host_name                       memcached.ha2,memcached.web2
service_description             redis
check_command                   check_redis
notifications_enabled           1
}

检查下nagios配置是否正解：
nagios -v  /etc/nagios/nagios.cfg

Nagios Core 3.2.1
Copyright (c) 2009-2010 Nagios Core Development Team and Community Contributors
Copyright (c) 1999-2009 Ethan Galstad
Last Modified: 03-09-2010
License: GPL

Website: http://www.nagios.org
Reading configuration data...
Read main config file okay...
Processing object config file '/etc/nagios/objects/commands.cfg'...
Processing object config file '/etc/nagios/objects/contacts.cfg'...
Processing object config file '/etc/nagios/objects/timeperiods.cfg'...
Processing object config file '/etc/nagios/objects/templates.cfg'...
Processing object config file '/etc/nagios/objects/linuxhosts.cfg'...
Processing object config file '/etc/nagios/objects/windows.cfg'...
Read object config files okay...

Running pre-flight check on configuration data...

Checking services...
Checked 32 services.
Checking hosts...
Checked 14 hosts.
Checking host groups...
Checked 4 host groups.
Checking service groups...
Checked 0 service groups.
Checking contacts...
Checked 3 contacts.
Checking contact groups...
Checked 2 contact groups.
Checking service escalations...
Checked 0 service escalations.
Checking service dependencies...
Checked 0 service dependencies.
Checking host escalations...
Checked 0 host escalations.
Checking host dependencies...
Checked 0 host dependencies.
Checking commands...
Checked 29 commands.
Checking time periods...
Checked 5 time periods.
Checking for circular paths between hosts...
Checking for circular host and service dependencies...
Checking global event handlers...
Checking obsessive compulsive processor commands...
Checking misc settings...

Total Warnings: 0
Total Errors:   0

Things look okay - No serious problems were detected during the pre-flight check

没问题，我们重新载入配置。

service nagios reload

再介绍一下用perl写nagios插件需要注意的地方：

1. 总是要生成一些输出内容；
2. 加上引用'use utils'并引用些通用模块来输出($TIMEOUT %ERRORS &print_revision &支持等)；
3. 总 是知道一些Perl插件的标准习惯，如：
   1. 退出时总是exit带 着$ERRORS{CRITICAL}、$ERRORS{OK}等；
   2. 使用getopt函数来处理命令行；
   3. 程序处理超 时问题；
   4. 当没有命令参数时要给出可调用print_usage；
   5. 使用标准的命令行选项开关(象-H 'host'、-V 'version'等)。

check_redisl.pl代码：

#!/usr/bin/perl

# nagios: -epn

################################################################################
# check_redis - Nagios Plugin for Redis checks.
#
# @author  farmer.luo at gmail.com
# @date    2010-05-12
# @license GPL v2
#
# check_nagios.pl -h <redis host> -p <redis port> -w <warning time> -c <critica time>
#
# Run the script need:
#
# perl -MCPAN -e shell
# install Redis
#
################################################################################

use strict;
use warnings;
use Redis;
use File::Basename;
use utils qw($TIMEOUT %ERRORS &print_revision &support);
use Time::Local;
use vars qw($opt_h); # Redis 主机
use vars qw($opt_p); # Redis 端口
use vars qw($opt_w); # 超过这个时间发出警告
use vars qw($opt_c); # 超过这个时间发出严重警告
use Getopt::Std;

$opt_h = "";
$opt_p = "6379";
$opt_w = 5;
$opt_c = 10;
my $r = "";

getopt('hpwcd');

if ( $opt_h eq "" ) {
help();
exit(1);
}

my $start = time();

redis_connect();

# print $@;
if ( $@ ) {
print "UNKNOWN - cann't connect to redis server:" . $opt_h . ".";
exit $ERRORS{"UNKNOWN"};
}

if ( redis_set() ) {
print "WARNING - redis server:" . $opt_h . ",set key error.";
exit $ERRORS{"WARNING"};
}

if ( redis_get() ) {
print "WARNING - redis server:" . $opt_h . ",get key error.";
exit $ERRORS{"WARNING"};
}

if ( redis_del() ) {
print "WARNING - redis server:" . $opt_h . ",del key error.";
exit $ERRORS{"WARNING"};
}

#sleep(3);
my $stop = time();

my $run = $stop - $start;

if ( $run > $opt_c ) {

print "CRITICAL - redis server(" . $opt_h . ") run for " . $run . " seconds!";
exit $ERRORS{"CRITICAL"};

} elsif ( $run > $opt_w ) {

print "WARNING - redis server(" . $opt_h . ") run for " . $run . " seconds!";
exit $ERRORS{"WARNING"};

} else {

redis_info();
redis_quit();
exit $ERRORS{"OK"};

}


sub help{

die "Usage:/n" , basename( $0 ) ,  " -h hostname -p port -w warning time -c critical time -d down time/n"

}

sub redis_connect{

my $redis_hp = $opt_h . ":" . $opt_p;

eval{ $r = Redis->new( server => $redis_hp ); };

}

sub redis_set{

$r->set( redis_nagios_key => 'test' ) || return 1;

return 0;
}

sub redis_get{

my $value = $r->get( 'redis_nagios_key' ) || return 1;

return 0;
}

sub redis_del{

$r->del( 'redis_nagios_key' ) || return 1;

return 0;
}

sub redis_info{

my $info_hash = $r->info;

print "OK - redis server(" . $opt_h . ") info:";

while ( my ($key, $value) = each(%$info_hash) ) {
print "$key => $value, ";
}

}

sub redis_quit{

$r->quit();

}