如果你已經使用Cacti Nagios 以及zabbix 等一系列監控工具來監控你的項目，但仍然達不到你想要的程序挂掉可以自動拉起并且郵件報警的功能，那麼請往下看，推薦一款及其好用的程序監控軟體Monit；
Monit是一款功能非常豐富的程序、檔案、目錄和裝置的監測軟體，适用于Linux/Unix平台。 它可以自動修複那些已經停止運作的程式,特使适合處理那些由于多種原因導緻的軟體錯誤，同時Monit 包含一個内嵌的 HTTP(S) Web 界面，你可以使用浏覽器友善地檢視 Monit 所監視的伺服器；
Monit官網：http://mmonit.com/monit/ CentOS可以直接：
# yum install monit -y 注：CentOS 可能需要安裝epel源才能有這個軟體包；
這裡就順便講一下怎麼安裝epel源：
## RHEL/CentOS 5 32-Bit ##
# wget http://download.fedoraproject.org/pub/epel/5/i386/epel-release-5-4.noarch.rpm
# rpm -ivh epel-release-5-4.noarch.rpm
## RHEL/CentOS 5 64-Bit ##
# wget http://download.fedoraproject.org/pub/epel/5/x86_64/epel-release-5-4.noarch.rpm
# rpm -ivh epel-release-5-4.noarch.rpm
RHEL/CentOS 6 32-64 Bit
## RHEL/CentOS 6 32-Bit ##
# wget http://download.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm
# rpm -ivh epel-release-6-8.noarch.rpm
## RHEL/CentOS 6 64-Bit ##
# wget http://download.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
# rpm -ivh epel-release-6-8.noarch.rpm
RHEL/CentOS 7 64 Bit
## RHEL/CentOS 7 64-Bit ##
# wget http://dl.fedoraproject.org/pub/epel/beta/7/x86_64/epel-release-7-0.2.noarch.rpm
# rpm -ivh epel-release-7-0.2.noarch.rpm
# ls -1 /etc/yum.repos.d/epel*
/etc/yum.repos.d/epel.repo
/etc/yum.repos.d/epel-testing.repo
# yum repolist
# yum --enablerepo=epel info monit
# yum --enablerepo=epel install monit Debian可以直接：
apt-get install monit -y 接下來看一下yum 裝完軟體包之後有哪些檔案：
# rpm -ql monit
/etc/logrotate.d/monit
/etc/monit.conf
/etc/monit.d
/etc/monit.d/logging
/etc/rc.d/init.d/monit
/usr/bin/monit
/usr/share/doc/monit-5.1.1
/usr/share/doc/monit-5.1.1/CHANGES.txt
/usr/share/doc/monit-5.1.1/COPYING
/usr/share/doc/monit-5.1.1/LICENSE
/usr/share/doc/monit-5.1.1/PLATFORMS
/usr/share/doc/monit-5.1.1/README
/usr/share/doc/monit-5.1.1/README.DEVELOPER
/usr/share/doc/monit-5.1.1/README.SSL
/usr/share/man/man1/monit.1.gz
/var/log/monit monit文檔：
https://mmonit.com/monit/documentation/ 檢視預設配置檔案：
# vim etc/monit.conf
set daemon 120 # 預設每隔兩分鐘檢測一次
set logfile syslog facility log_daemon #預設monit日志為syslog
set idfile /var/.monit.id #設定Monit監控項目的唯一id檔案位置，預設在$HOME/.monit.id
set statefile /var/.monit.state #預設存儲每個周期内monitorinig 狀态的檔案
set mailserver mail.bar.baz, # 預設的主郵件伺服器
mailserver 支援格式為：
SET MAILSERVER <hostname|ip-address [PORT number] [USERNAME string] [PASSWORD string] [using SSLAUTO|SSLV2|SSLV3|TLSV1|TLSV11|TLSV12] [CERTMD5 checksum]>, ...
[with TIMEOUT X SECONDS]
[using HOSTNAME hostname]
例如:
set mailserver smtp.gmail.com port 587 username "[email protected]" password "password" using tlsv1 with timeout 30 seconds
set eventqueue #預設當郵件伺服器不可用時使用eventqueue存儲報警事件
basedir /var/monit
slots 100 #限制隊列大小
set mail-format {
from: [email protected]
reply-to: [email protected]
subject: $SERVICE $EVENT at $DATE
message: Monit $ACTION $SERVICE at $DATE on $HOST: $DESCRIPTION.
Yours sincerely,
monit
}
set alert [email protected] # receive all alerts
set httpd port 2812 and # 引用monit自己封裝的web server來監控monit的監控項目狀态；
use address localhost # only accept connection from localhost
allow localhost # allow localhost to connect to the server and
allow admin:monit # require user 'admin' with password 'monit'
allow @monit # allow users of group 'monit' to connect (rw)
allow @users readonly # allow users of group 'users' to connect readonly
include /etc/monit.d/* 看完這些是不是已經對配置檔案有所了解了呢，小編為剛剛接觸的同學準備了調優後的一個執行個體配置檔案如下：
# vim etc/monit.conf
set daemon 15 # check services at 2-minute intervals
set logfile /var/log/monit.log
set idfile /var/.monit.id
set statefile /var/.monit.state
set mailserver mail.wz.com
username "[email protected]" password "cacti"
with timeout 15 seconds
set eventqueue
basedir /var/monit # set the base directory where events will be stored
slots 100 # optionally limit the queue size
set mail-format {
from: [email protected]
subject: Monit Alert -- Host $HOST 's $SERVICE $DESCRIPTION
message:
Date: $DATE
Action: $ACTION
Host: $HOST
Description:
Host $HOST 's $SERVICE $DESCRIPTION
$EVENT Service $SERVICE
$DESCRIPTION
}
set alert [email protected] # receive all alerts
set httpd port 11111 and
allow localhost
allow 192.168.3.0/24
allow username:password
include /etc/monit.d/* 這裡需要注意的是，上面配置的郵件服務server需要用到使用者名密碼認證，能力強的同學可以内網搭建一個郵件系統，覺得麻煩的同學可以用騰訊郵箱或者126...balabala
最後一項include /etc/monit.d/* 是定義監控項目配置檔案放置的位置；我們需要監控哪些項目其配置檔案就可以放在這裡；
那小編又為同學們準備了一個執行個體：
# vim /etc/monit.d/perl-fcgi.conf
check process perl-fcgi with pidfile /opt/logs/perl-fcgi.pid
start program = "/etc/init.d/perl-fcgi start"
stop program = "/etc/init.d/perl-fcgi stop"
if 5 restarts within 5 cycles then timeout
# vim /etc/monit.d/nginx.conf
check process nginx with pidfile /opt/logs/nginx.pid
start program = "/etc/init.d/nginx start"
stop program = "/etc/init.d/nginx stop"
if failed port 80 protocol http then restart
if 5 restarts within 5 cycles then timeout
# vim /etc/monit.d/mysql.conf
check process mysqld with pidfile /data/mariadb/mariadb.pid
start program = "/etc/init.d/mysqld start"
stop program = "/etc/init.d/mysqld stop"
#if failed port 3306 protocol mysql then restart
if failed unixsocket /tmp/mysql.sock then restart
if 5 restarts within 5 cycles then timeout 配置檔案有了，接下來檢測一下文法對不對呢：
# monit -t
Control file syntax OK 啟動monit：
/etc/init.d/monit start
Starting monit: monit: generated unique Monit id 5d83a4c163d9bc0218b77f1aae3cdf2d and stored to '/var/.monit.id'
[ OK ] 注意：
如果你的系統裡有防火牆，這裡需要添加防火牆規則；
monit的配置檔案中有一個自帶的web server用來監控monit裡面的監控項目的狀态，有個預設端口2812，如果沒修改的話就添加2812端口的規則，如果修改了就添加你修改後的端口防火牆規則；
monit預設2812端口規則：
# vim /etc/sysconfig/iptables
-A INPUT -p tcp --dport 2812 -j ACCEPT monit修改後端口11111規則：
# vim /etc/sysconfig/iptables
-A INPUT -p tcp --dport 11111 -j ACCEPT 記得重新開機iptables：
/etc/init.d/iptables restart 接下來在浏覽器裡測試通路monit的狀态：
http://192.168.3.5:11111/
輸入配置檔案中的賬号和密碼：username password 
盡情enjoy吧！
這裡附上幾張郵件報警的截圖：
測試nginx關閉之後是否可以自動拉起呢？
/etc/init.d/nginx stop 
馬上就是見證奇迹的時刻！
看，快看！