keepalived实现高可用nginx反向代理

一、环境配置：

IP：192.168.1.30 VIP：192.168.1.34 keepalive+nginx
IP：192.168.1.31 VIP：192.168.1.34 keepalive+nginx
IP：192.168.1.35 web1
IP：192.168.1.36 web2

二、两台负载均衡的机器都安装 keepalived+nginx

1、安装keepalived

# yum -y install keepalived

2、创建nginx用户组和nginx用户

# groupadd -r nginx
# useradd -g nginx -r nginx

3、编译安装nginx-1.4.7

# tar xf nginx-1.4.7.tar.gz
# cd nginx-1.4.7
# ./configure --prefix=/usr --sbin-path=/usr/sbin/nginx --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --pid-path=/var/run/nginx/nginx.pid  --lock-path=/var/lock/nginx.lock --user=nginx --group=nginx --with-http_ssl_module --with-http_flv_module --with-http_stub_status_module --with-http_gzip_static_module --http-client-body-temp-path=/usr/local/nginx/client/ --http-proxy-temp-path=/usr/local/nginx/proxy/ --http-fastcgi-temp-path=/usr/local/nginx/fcgi/ --http-uwsgi-temp-path=/usr/local/nginx/uwsgi --http-scgi-temp-path=/usr/local/nginx/scgi --with-pcre

出现./configure: error: C compiler cc is not found
解决办法：yum -y install gcc gcc-c++ autoconf automake make
出现./configure: error: the HTTP rewrite module requires the PCRE library.
解决办法： yum -y install pcre-devel
出现./configure: error: SSL modules require the OpenSSL library.
解决办法：yum -y install openssl openssl-devel

# make && make install

4、检查配置文件是否有语法错误

# nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: [emerg] mkdir() "/usr/local/nginx/client/" failed (2: No such file or directory)
nginx: configuration file /etc/nginx/nginx.conf test failed

5、修改错误，再次检测

# mkdir /usr/local/nginx
# nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

6、为nginx提供SysV init脚本

# vim /etc/rc.d/init.d/nginx
#!/bin/sh
#
# nginx - this script starts and stops the nginx daemon
#
# chkconfig:   - 85 15 
# description:  Nginx is an HTTP(S) server, HTTP(S) reverse 
#               proxy and IMAP/POP3 proxy server
# processname: nginx
# config:      /etc/nginx/nginx.conf
# config:      /etc/sysconfig/nginx
# pidfile:     /var/run/nginx.pid
  
# Source function library.
. /etc/rc.d/init.d/functions
  
# Source networking configuration.
. /etc/sysconfig/network
  
# Check that networking is up.
[ "$NETWORKING" = "no" ] && exit 0
  
nginx="/usr/sbin/nginx"
prog=$(basename $nginx)
  
NGINX_CONF_FILE="/etc/nginx/nginx.conf"
  
[ -f /etc/sysconfig/nginx ] && . /etc/sysconfig/nginx
  
lockfile=/var/lock/subsys/nginx
  
make_dirs() {
   # make required directories
   user=`nginx -V 2>&1 | grep "configure arguments:" | sed 's/[^*]*--user=([^ ]*).*/1/g' -`
   options=`$nginx -V 2>&1 | grep 'configure arguments:'`
   for opt in $options; do
       if [ `echo $opt | grep '.*-temp-path'` ]; then
           value=`echo $opt | cut -d "=" -f 2`
           if [ ! -d "$value" ]; then
               # echo "creating" $value
               mkdir -p $value && chown -R $user $value
           fi
       fi
   done
}
  
start() {
    [ -x $nginx ] || exit 5
    [ -f $NGINX_CONF_FILE ] || exit 6
    make_dirs
    echo -n $"Starting $prog: "
    daemon $nginx -c $NGINX_CONF_FILE
    retval=$?
    echo
    [ $retval -eq 0 ] && touch $lockfile
    return $retval
}
  
stop() {
    echo -n $"Stopping $prog: "
    killproc $prog -QUIT
    retval=$?
    echo
    [ $retval -eq 0 ] && rm -f $lockfile
    return $retval
}
  
restart() {
    configtest || return $?
    stop
    sleep 1
    start
}
  
reload() {
    configtest || return $?
    echo -n $"Reloading $prog: "
    killproc $nginx -HUP
    RETVAL=$?
    echo
}
  
force_reload() {
    restart
}
  
configtest() {
  $nginx -t -c $NGINX_CONF_FILE
}
  
rh_status() {
    status $prog
}
  
rh_status_q() {
    rh_status >/dev/null 2>&1
}
  
case "$1" in
    start)
        rh_status_q && exit 0
        $1
        ;;
    stop)
        rh_status_q || exit 0
        $1
        ;;
    restart|configtest)
        $1
        ;;
    reload)
        rh_status_q || exit 7
        $1
        ;;
    force-reload)
        force_reload
        ;;
    status)
        rh_status
        ;;
    condrestart|try-restart)
        rh_status_q || exit 0
            ;;
    *)
        echo $"Usage: $0 {start|stop|status|restart|condrestart|try-restart|reload|force-reload|configtest}"
        exit 2
esac

8、赋予nginx脚本执行权限，添加至服务管理列表，并让其开机自动启动

# chmod +x /etc/rc.d/init.d/nginx
# chkconfig --add nginx
# chkconfig nginx on

三、配置nginx为反向代理服务器

1、编辑nginx.conf配置文件

# cd /etc/nginx/
# vim nginx.conf　　#在nginx.conf配置文件中的http段内添加如下的内容
upstream webservers {
    server 192.168.1.35;
    server 192.168.1.36;
}
server {
    listen 80;
    server_name www.hhh.com;
    location / {
        proxy_pass http://webservers;
        proxy_set_header X-Real-IP $remote_addr;
    }
}

注：两台负载的主机的nginx.conf添加的内容是一样的

四、配置keepalived

1、编辑keepalived.conf配置文件

# cd /etc/keepalived/
# vim keepalived.conf
#IP地址为192.168.1.30的配置文件内容为：
! Configuration File for keepalived

global_defs {
notification_email {
acassen@firewall.loc
failover@firewall.loc
sysadmin@firewall.loc
}
notification_email_from Alexandre.Cassen@firewall.loc
smtp_server 192.168.200.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}

vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.1.34
}
}
notify_master "/etc/init.d/nginx start"
notify_backup "/etc/init.d/nginx stop"
notify_fault "/etc/init.d/nginx stop"
}

#IP地址为192.168.1.31的配置文件内容为：
! Configuration File for keepalived

global_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc

! Configuration File for keepalived

global_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}

vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 51
    priority 99
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.1.34
    }
}
    notify_master "/etc/init.d/nginx start"
    notify_backup "/etc/init.d/nginx stop"
    notify_fault "/etc/init.d/nginx stop"
}

2、配置web1和web2服务器

#yum install httpd -y

3、编辑web1测试页面，启动httpd服务

# vim /var/www/html/index.html
内容为:<h1>www1.hhh.com</h1>

# /etc/init.d/httpd start

4、编辑web2测试页面，启动httpd服务

# vim /var/www/html/index.html
内容为:<h1>www2.hhh.com</h1>
# /etc/init.d/httpd start

五、启动keepalived服务并进行测试

1、启动两台主机的keepalived服务

# /etc/init.d/keepalived start

2、在浏览器中输入192.168.1.34刷新可以得到以下的结果

3、关闭192.168.1.30的keepalived服务

# /etc/init.d/keepalived stop

4、再次在浏览器输入192.168.1.34

5、由以上结果可以，keepalived实现了nginx反向代理的高可用和nginx实现了web的负载均衡效果