Ansible实现主备模式的高可用(Keepalived)

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前言

  Ansible是一款极其简单的IT自动化运维工具,基于Python开发,集合了众多运维工具(puppet、cfengine、chef、func、fabric)的优点,实现了批量系统配置、批量程序部署、批量运行命令等功能。Ansible是基于模块工作的,本身没有批量部署的能力,真正具有批量部署的是Ansible所运行的模块,Ansible只是提供一种框架。Ansible主要承担的工作包括:配置管理、服务即时开通、应用部署、流程编排、监控告警、日志记录等。

  Ansible的基本架构:

技术分享图片

  • 核心模块(Core Module):在模块库(Module Library)中分为两块,一个是核心模块,另外一个就是自定义模块(Custom Modules)。核心模块中都是Ansible自带的模块,模块资源分发到远程节点使其执行特定任务或匹配一个特定的状态;
  • 自定义模块(Custom Modules):如果Ansible满足不了你所需求的模块,则在此处添加自定义化的模块;
  • 插件(Plugins):协助模块来完成某个功能;
  • 剧本(Playbooks):定义需要给远程主机执行的一系列任务;
  • 连接插件(Connectior Plugins):Ansible默认基于SSH连接到目标机器上执行操作的,但也支持不同的连接方法,此时需要连接插件来帮助我们完成连接;
  • 主机清单(Host Inventory):定义需要管理的主机,小型环境中我们只需要在host文件中写入主机的IP地址即可,但到了中大型环境我们有可能需要使用静态inventory或者动态主机清单来生成我们所需要执行的目标主机。

实验拓扑图

技术分享图片

  两台nginx作为Web Proxy,配置实现KeepAlived做主备;后端两台Apache,一台部署Apache+php,一台部署Apache+mysql

搭建Ansible

[[email protected] ~]# systemctl stop firewalld.service
[[email protected] ~]# systemctl disable firewalld.serive
[[email protected] ~]# vim /etc/selinux/config
    ...
    SELINUX=disabled
    ...
[[email protected] ~]# init 6
[[email protected] ~]# ntpdate ntp1.aliyun.com
[[email protected] ~]# yum -y install ansible
[[email protected] ~]# vim /etc/ansible/hosts
    ...
    [hasrvs]
    192.168.4.117
    192.168.4.118
    [websrvs]
    192.168.4.119
    192.168.4.120
  [php]
  192.168.4.119
  [mysql]
  192.168.4.120 [[email protected] ~]# vim /etc/hosts ... 192.168.4.117 nginx1 192.168.4.118 nginx2 192.168.4.119 apache1 192.168.4.120 apache2 [[email protected] ~]# ssh-keygen -t rsa -N ‘‘ #生成密钥对,实现ssh免密码登录 Generating public/private rsa key pair. Enter file in which to save the key (/root/.ssh/id_rsa): Created directory ‘/root/.ssh‘. Your identification has been saved in /root/.ssh/id_rsa. Your public key has been saved in /root/.ssh/id_rsa.pub [[email protected] ~]# ssh-copy-id -i .ssh/id_rsa.pub [email protected] #复制公钥到各远程主机 [[email protected] ~]# ssh-copy-id -i .ssh/id_rsa.pub [email protected] [[email protected] ~]# ssh-copy-id -i .ssh/id_rsa.pub [email protected] [[email protected] ~]# ssh-copy-id -i .ssh/id_rsa.pub [email protected]

 测试连通性

[[email protected] ~]# ansible all -m ping
    192.168.4.117 | SUCCESS => {
        "changed": false, 
        "ping": "pong"
    }
    192.168.4.118 | SUCCESS => {
        "changed": false, 
        "ping": "pong"
    }
    192.168.4.120 | SUCCESS => {
        "changed": false, 
        "ping": "pong"
    }
    192.168.4.119 | SUCCESS => {
        "changed": false, 
        "ping": "pong"
    }

同步时间,关闭firewalld及selinux

[[email protected] ~]# ansible all -m shell -a ‘echo "TZ=‘Asia/Shanghai‘; export TZ" >> /etc/profile‘
[[email protected] ~]# ansible all -m cron -a ‘minute=*/5 job="/usr/sbin/ntpdate ntp1.aliyun.com &> /dev/null" name=UpdateTime‘  #每隔3分钟同步一次时间
[[email protected] ~]# ansible all -m shell -a ‘systemctl stop firewalld.service; systemctl disable firewalld.service; setenfore 0‘

 配置Apache服务的roles

[[email protected] ~]# mkdir -pv /etc/ansible/roles/apache/{files,templates,tasks,handlers,vars,meta,default}  #创建相关目录
[[email protected] ~]# vim /etc/ansible/roles/apache/templates/vhost.conf.j2  #Apache主机模板
    <virtualhost *:80>
        ServerName www.test.org
        DirectoryIndex index.html index.php
        DocumentRoot /var/www/html
        ProxyRequests off
        ProxyPassMatch ^/(.*.php)$ fcgi://192.168.4.119:9000/var/www/html/$1
        ProxyPassMatch ^/(ping|status)$ fcgi://192.168.4.119:9000/$1
        <Directory />
        options FollowSymlinks
        Allowoverride None
        Require all granted
        </Directory>
    </virtualhost>
[[email protected] ~]# vim /etc/ansible/roles/apache/templates/index.html  #Apache主页
    <h1> This is {{ ansible_hostname }} </h1>
[[email protected] ~]# vim /etc/ansible/roles/apache/files/index.php
    <?php
        phpinfo();
    ?>
[[email protected] ~]# vim /etc/ansible/roles/apache/tasks/main.yml  #定义实现Apache的task
    - name: install apache
      yum: name=httpd state=latest
    - name: copy conf
      template: src=vhost.conf.j2 dest=/etc/httpd/conf.d/vhost.conf
    - name: copy index.html
      template: src=index.html dest=/var/www/html/index.html
    - name: copy index.php
      copy: src=index.php dest=/var/www/html/index.php
    - name: start httpd
      service: name=httpd state=started

配置php-fpm服务的roles

[[email protected] ~]# mkdir -pv /etc/ansible/roles/php-fpm/{files,templates,tasks,handlers,vars,meta,default}  #创建相关目录
[[email protected] ~]# cp /etc/php-fpm.d/www.conf /etc/ansible/roles/php-fpm/templates/www.conf.j2  #直接复制事先准备的配置模板
[[email protected] ~]# vim /etc/ansible/roles/php-fpm/templates/www.conf.j2
    #修改如下配置
    listem = 0.0.0.0:9000
    ;listen.allowed_clients = 127.0.0.1
    pm.status_path = /status
    ping.path = /ping
    ping.response = pong
[[email protected] ~]# vim /etc/ansible/roles/php-fpm/tasks/main.yml  #定义实现php-fpm的task
    - name: install php
      yum: name={{ item }} state=latest
      with_items:
      - php-fpm
      - php-mysql
      - php-mbstring
      - php-mcrypt
    - name: copy config
      template: src=www.conf.j2 dest=/etc/php-fpm.d/www.conf
    - name: create directory
      file: path=/var/lib/php/session group=apache owner=apache state=directory
    - name: start php-fpm
      service: name=php-fpm state=started

 配置MySQL服务的roles

[[email protected] ~]# mkdir -pv /etc/ansible/roles/mysql/{files,templates,tasks,handlers,vars,meta,default}  #创建相关目录
[[email protected] ~]# cp /etc/my.cnf /etc/ansible/roles/mysql/templates/my.cnf.j2  #复制事先准备的模板
[[email protected] ~]# vim /etc/ansible/roles/mysql/templates/my.cnf.j2
    #添加如下配置
    skip-name-resolve=ON
    innodb-file-per-table=ON
[[email protected] ~]# vim /etc/ansible/roles/mysql/tasks/main.yml  #定义实现MySQL的task
    - name: install mysql
      yum: name=mariadb-server state=latest
    - name: copy config
      template: src=my.cnf.j2 dest=/etc/my.cnf
    - name: start mysql
      service: name=mariadb state=started

配置Nginx服务的roles

[[email protected] ~]# mkdir -pv /etc/ansible/roles/nginx/{files,templates,tasks,handlers,vars,meta,default}  #创建相关目录
[[email protected] ~]# cp /etc/nginx/nginx.conf /etc/ansible/roles/nginx/templates/nginx.conf.j2  #复制事先准备的模板
[[email protected] ~]# vim /etc/ansible/roles/nginx/templates/nginx.conf.j2
  #修改配置 http { ... upstream websrvs { server 192.168.4.119:80; server 192.168.4.120:80; server 127.0.0.1:80 backup; } server { listen 80; include /etc/nginx/default.d/*.conf; location / { proxy_pass http://websrvs; proxy_set_header host $http_host; proxy_set_header X-Forward-For $remote_addr; } ... } ... } [[email protected] ~]# vim /etc/ansible/roles/nginx/templates/localhost.conf.j2 #定义本地的Nginx服务 server { listen 127.0.0.1:80; root /usr/share/nginx/html; index index.html; } [[email protected] ~]# vim /etc/ansible/roles/nginx/templates/index.html <h1> Balance Server {{ ansible_hostname }} </h1> [[email protected] ~]# vim /etc/ansible/roles/nginx/tasks/main.yml #定义实现Nginx的task - name: install nginx yum: name=nginx state=latest - name: copy nginx conf template: src=nginx.conf.j2 dest=/etc/nginx/nginx.conf - name: copy local conf template: src=localhost.conf.j2 dest=/etc/nginx/conf.d/localhost.conf - name: copy index template: src=index.html dest=/usr/share/nginx/html/index.html - name: start nginx service: name=nginx state=started

 配置KeepAlived服务的roles

[[email protected] keepalived]# mkdir -pv /etc/ansible/roles/keepalived/{files,templates,tasks,handlers,vars,meta,default}  #创建相关目录
[[email protected] keepalived]# vim /etc/ansible/roles/keepalived/templates/keepalived.conf.j2  #KeepAlived配置文件
    global_defs {
           notification_email {
             [email protected]
           }
           notification_email_from [email protected]
           smtp_server 127.0.0.1
           smtp_connect_timeout 30
           router_id {{ ansible_nodename }}
           vrrp_skip_check_adv_addr
           vrrp_mcast_group4 224.0.0.10
    }
    
    vrrp_instance VIP_1 {
        state {{ keepalived_role }}
        interface eno16777736
        virtual_router_id 1
        priority {{ keepalived_pri }}
        advert_int 1
        authentication {
            auth_type PASS
            auth_pass %&hhjj99
        }
        virtual_ipaddress {
          192.168.4.155/24 dev eno16777736 label eno16777736:0
        }
    }
[[email protected] keepalived]# vim /etc/ansible/hosts  #添加变量
        ...
    [hasrvs]
    192.168.4.117 keepalived_role=MASTER keepalived_pri=100
    192.168.4.118 keepalived_role=BACKUP keepalived_pri=99
    ...
[[email protected] keepalived]# vim /etc/ansible/roles/keepalived/tasks/main.yml  #定义实现Keepalived的task
    - name: install keepalived
      yum: name=keepalived state=latest
    - name: copy config
      template: src=keepalived.conf.j2 dest=/etc/keepalived/keepalived.conf
    - name: start keepalived
      service: name=keepalived state=started

 配置Apache+PHP服务的playbook

[[email protected] keepalived]# mkdir /etc/ansible/playbooks  #创建playbook存放目录
[[email protected] roles]# vim /etc/ansible/playbooks/ap1.yml  定义实现Apache+php-fpm的playbook
    - hosts: php
      remote_user: root
      roles:
      - apache
      - php-fpm
[[email protected] roles]# ansible-playbook --syntax-check /etc/ansible/playbooks/ap1.yml  #检查是否有语法错误
[[email protected] roles]# ansible-playbook /etc/ansible/playbooks/ap1.yml  #执行

配置Apache+MySQL服务的playbook

[[email protected] ~]# vim /etc/ansible/playbooks/ap2.yml
    - hosts: mysql
      remote_user: root
      roles:
      - apache
      - mysql
[[email protected] ~]# ansible-playbook --syntax-check /etc/ansibleplaybooks/ap2.yml
[[email protected] ~]# ansible-playbook /etc/ansibleplaybooks/ap2.yml

 配置Nginx+Keepalived服务的playbook

[[email protected] ~]# vim /etc/ansible/playbooks/ha.yml
    - hosts: hasrvs
      remote_user: root
      roles:
      - nginx
      - keepalived 
[[email protected] ~]# ansible-playbook --syntax-check /etc/ansible/playbooks/ha.yml 
[[email protected] ~]# ansible-playbook /etc/ansible/playbooks/ha.yml

 客户端测试访问

[[email protected] ~]# vim /etc/hosts
    ...
    192.168.4.155 www.test.org
    ...
[[email protected] ~]# for i in {1..10};do curl http://www.test.org;done
    <h1> This is apache2 </h1>
    <h1> This is apache1 </h1>
    <h1> This is apache2 </h1>
    <h1> This is apache1 </h1>
    <h1> This is apache2 </h1>
    <h1> This is apache1 </h1>
    <h1> This is apache2 </h1>
    <h1> This is apache1 </h1>
    <h1> This is apache2 </h1>
    <h1> This is apache1 </h1>

小插曲:

  [[email protected] ~]# ansible all -m ping --list-hosts
  ERROR! Unexpected Exception, this is probably a bug: (cryptography 0.8.2 (/usr/lib64/python2.7/site-packages), Requirement.parse(‘cryptography>=1.1‘))

  运行ansible命令时报错,python的cryptography版本必须>=1.1。

  解决办法:

  [[email protected] ~]# yum -y install python-pip

  [[email protected] ~]# pip install --upgrade cryptography







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