ansible自动部署Keepalived实现Nginx服务双机热备

脚本实现通过ansible-playbook自动化安装Keepalived和配置，主要解决问题如下：

• Keepalived自动化安装；
• keepalived_vrid配置，自动根据vip获取最后一段作为vrid，确保同一网段不会出现vrid冲突导致HA切换失败的问题；
• 自动配置Keepalived；
• HA检测脚本自定义，根据脚本内容，来做redis或nginx或其他软件的双机热备；
• 自动配置vip给Keepalived
• 设置Keepalived开机启动，加入系统服务；

Keepalived安装脚本如下：

 - name: keepalived install and configuration
   hosts: "{{ host }}"
   user: root

   tasks:
     - name: Create the dir
       file: path={{ item }} state=directory
       with_items:
         - /usr/local/keepalived
         - /etc/keepalived
         - /keepalived_install

     - name: install rpm pkgs for Keepalived
       yum: name={{ item }} state=present
       with_items:
         - make
         - wget
         - gcc
         - gcc-c++
         - openssl
         - openssl-devel
         - popt-devel
         - automake
         - autoconf
         - libtool
         - ipvsadm
         - popt-devel
         - popt-static
         - libnl-devel
         - libnfnetlink-devel
         - nmap

     - name: download keepalived
       get_url: url=https://www.keepalived.org/software/keepalived-1.2.19.tar.gz dest=/keepalived_install

     - name: unarchive keepalived
       unarchive: src=/keepalived_install/keepalived-1.2.19.tar.gz dest=/keepalived_install copy=no

     - name: compile and install keepalived
       shell: cd /keepalived_install/keepalived-1.2.19 && ./configure --prefix=/usr/local/keepalived && make && make install

     - name: compile and install keepalived
       command: "{{ item }}"
       with_items:
         - /bin/cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/
         - /bin/cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
         - /bin/cp /usr/local/keepalived/sbin/keepalived /bin/keepalived
         - /bin/chmod +x /etc/init.d/keepalived
         - /sbin/chkconfig --add keepalived
         - /sbin/chkconfig --level 345 keepalived on

     - name: configure keepalived
       template: src=/ansible/roles/test/template/keepalived.conf.j2 dest=/etc/keepalived/keepalived.conf
       notify: restart keepalived

     - name: copy nginx service check scripts to remote host
       template: src=/ansible/roles/test/template/check_nginx.sh.j2 dest=/usr/local/keepalived/check_nginx.sh mode=0755

     - name: copy vrid config_scripts to remote host
       template: src=/ansible/roles/test/template/replace_vrid.sh.j2 dest=/tmp/keepalived.sh mode=0755

     - name: modify keepalived_vrid
       shell: sh /tmp/keepalived.sh

     - name: delete the tmp files.
       file: path={{ item }} state=absent
       with_items:
         - /keepalived_install/keepalived-1.2.19.tar.gz
         - /keepalived_install/keepalived-1.2.19
         - /keepalived_install
         - /tmp/keepalived.sh

   handlers:
     - name: config vrid
       shell: bash /tmp/keepalived.sh

   handlers:
     - name: restart keepalived
       service: name=keepalived enabled=yes state=restarted

keepalived_install.yml

使用方法：

Usage: ansible-playbook -i /tmp/testhost /ansible/roles/keepalived/tasks/keepalived_install.yml -e "{'host':'10.99.99.99','nginx_havip':'10.99.99.100'}"

Keepalived配置模板

 ! Configuration File for keepalived

 global_defs {
    router_id Nginx
 }

 vrrp_script chk_nginx {
     script "/usr/local/keepalived/check_nginx.sh"
     interval 2
     fall 3
     weight -5
     rise 1
 }

 vrrp_instance VI_1 {
     state BACKUP
     interface {{ ansible_default_ipv4['alias'] }}
     virtual_router_id keepalived_vrid
     priority 90
     nopreempt
     advert_int 1
     authentication {
         auth_type PASS
         auth_pass 1111
     }
     virtual_ipaddress {
         {{ nginx_havip }}
     }
     track_script {
         chk_nginx
    }
 }

keepalived.conf.j2

NGINX服务检测脚本模板

 #!/bin/sh
 # check nginx server status

 # Source Function Library
 . /etc/init.d/functions

 NGINX="/usr/local/nginx/sbin/nginx"
 NGINX_CONF="/usr/local/nginx/conf/nginx.conf"
 NGINX_PID="/usr/local/nginx/logs/nginx.pid"
 PORT=

 start_nginx() {
     daemon $NGINX -c $NGINX_CONF
 }

 stop_nginx() {
     killproc -p $NGINX_PID $NGINX -TERM
 }

 nmap localhost -p $PORT | grep "$PORT/tcp open"

 if [ $? -ne  ];then
     stop_nginx
     start_nginx
     sleep
     nmap localhost -p $PORT | grep "$PORT/tcp open"
     [ $? -ne  ] && /etc/init.d/keepalived stop
 fi

check_nginx.sh.j2

keepalived配置中虚拟路由id替换脚本

 #!/bin/sh
 havip={{ nginx_havip }}
 vrid=`echo ${havip##*.}`
 sed -i "s/keepalived_vrid/$vrid/" /etc/keepalived/keepalived.conf

replace_vrid.sh.j2

说明：

执行此脚本之前，需要安装nginx。