Ansible-Playbook-template算数运算以及流程控制

古城微笑少年丶 2023-10-03 12:50 7阅读 0赞

###### template中使用流程控制 for 和 if ######

template中也可以使用流程控制 for 循环和 if 条件判断，实现动态生成文件功能

范例

#temlnginx2.yml
    ---
    - hosts: websrvs
      remote_user: root
      vars:
        nginx_vhosts:
          - 81
          - 82
          - 83
      tasks:
        - name: template config
          template: src=nginx.conf.j2 dest=/data/nginx.conf
    
    #templates/nginx.conf2.j2
    {
        % for vhost in  nginx_vhosts %}
    server {
        
       listen {
        {
         vhost }}
    }
    {
        % endfor %}
    
    ansible-playbook -C  templnginx2.yml  --limit 10.0.0.8
    
    #生成的结果：
    server {
        
       listen 81   
    }
    server {
        
       listen 82   
    }
    server {
        
       listen 83   
    }

YAML

范例：

#temlnginx3.yml
    ---
    - hosts: websrvs
      remote_user: root
      vars:
        nginx_vhosts:
          - listen: 8080
      tasks:
        - name: config file
          template: src=nginx.conf3.j2 dest=/data/nginx3.conf
    
    #templates/nginx.conf3.j2
    {
        % for vhost in nginx_vhosts %}   
    server {
        
      listen {
        {
         vhost.listen }}
    }
    {
        % endfor %}
    
    ansible-playbook   templnginx3.yml  --limit 10.0.0.8
    
    #生成的结果
    server {
        
      listen 8080  
    }

范例：

#templnginx4.yml
    - hosts: websrvs
      remote_user: root
      vars:
        nginx_vhosts:
          - listen: 8080
            server_name: "web1.magedu.com"
            root: "/var/www/nginx/web1/"
          - listen: 8081
            server_name: "web2.magedu.com"
            root: "/var/www/nginx/web2/"
          - {
        listen: 8082, server_name: "web3.magedu.com", root: "/var/www/nginx/web3/"}
      tasks:
        - name: template config 
          template: src=nginx.conf4.j2 dest=/data/nginx4.conf
    
    # templates/nginx.conf4.j2
    {
        % for vhost in nginx_vhosts %}
    server {
        
       listen {
        {
         vhost.listen }}
       server_name {
        {
         vhost.server_name }}
       root {
        {
         vhost.root }}  
    }
    {
        % endfor %}
    
    ansible-playbook  templnginx4.yml --limit 10.0.0.8
    
    #生成结果：
    server {
        
        listen 8080
        server_name web1.magedu.com
        root /var/www/nginx/web1/  
    }
    server {
        
        listen 8081
        server_name web2.magedu.com
        root /var/www/nginx/web2/  
    }
    server {
        
        listen 8082
        server_name web3.magedu.com
        root /var/www/nginx/web3/  
    }

YAML

在模版文件中还可以使用 if条件判断，决定是否生成相关的配置信息

范例：

#templnginx5.yml
    - hosts: websrvs
      remote_user: root
      vars:
        nginx_vhosts:
          - web1:
            listen: 8080
            root: "/var/www/nginx/web1/"
          - web2:
            listen: 8080
            server_name: "web2.magedu.com"
            root: "/var/www/nginx/web2/"
          - web3:
            listen: 8080
            server_name: "web3.magedu.com"
            root: "/var/www/nginx/web3/"
      tasks:
        - name: template config to 
          template: src=nginx.conf5.j2 dest=/data/nginx5.conf
    
    #templates/nginx.conf5.j2
    {
        % for vhost in  nginx_vhosts %}
    server {
        
       listen {
        {
         vhost.listen }}
       {
        % if vhost.server_name is defined %}
    server_name {
        {
         vhost.server_name }}
       {
        % endif %}
    root  {
        {
         vhost.root }}
    }
    {
        % endfor %}
    
    #生成的结果
    server {
        
       listen 8080
       root  /var/www/nginx/web1/
    }
    server {
        
       listen 8080
       server_name web2.magedu.com
       root  /var/www/nginx/web2/
    }
    server {
        
       listen 8080
       server_name web3.magedu.com
       root  /var/www/nginx/web3/
    }

YAML

##### playbook使用 when #####

when语句，可以实现条件测试。如果需要根据变量、facts或此前任务的执行结果来做为某task执行与否的前提时要用到条件测试,通过在task后添加when子句即可使用条件测试，jinja2的语法格式

范例：

---
    - hosts: websrvs
      remote_user: root
      tasks:
        - name: "shutdown RedHat flavored systems"
          command: /sbin/shutdown -h now
          when: ansible_os_family == "RedHat"

YAML

范例：

---
    - hosts: websrvs
      remote_user: root
      tasks:
        - name: add group nginx
          tags: user
          user: name=nginx state=present
        - name: add user nginx
          user: name=nginx state=present group=nginx
        - name: Install Nginx
          yum: name=nginx state=present
        - name: restart Nginx
          service: name=nginx state=restarted
          when: ansible_distribution_major_version == “6”

YAML

范例：

---
    - hosts: websrvs
      remote_user: root
      tasks: 
        - name: install conf file to centos7
          template: src=nginx.conf.c7.j2 dest=/etc/nginx/nginx.conf
          when: ansible_distribution_major_version == "7"
        - name: install conf file to centos6
          template: src=nginx.conf.c6.j2 dest=/etc/nginx/nginx.conf
          when: ansible_distribution_major_version == "6"

YAML

##### playbook 使用迭代 with\_items #####

迭代：当有需要重复性执行的任务时，可以使用迭代机制  
对迭代项的引用，固定变量名为”item“  
要在task中使用with\_items给定要迭代的元素列表

**列表元素格式：**

*  字符串
 *  字典

范例：

---
    - hosts: websrvs
      remote_user: root
    
      tasks:
        - name: add several users
          user: name={
        {
         item }} state=present groups=wheel
          with_items:
            - testuser1
            - testuser2
    #上面语句的功能等同于下面的语句
        - name: add user testuser1
          user: name=testuser1 state=present groups=wheel
        - name: add user testuser2
          user: name=testuser2 state=present groups=wheel

范例：

---
    #remove mariadb server
    - hosts: appsrvs:!192.168.38.8
      remote_user: root
    
      tasks:
        - name: stop service
          shell: /etc/init.d/mysqld stop
        - name:  delete files and dir
          file: path={
        {
        item}} state=absent
          with_items:
            - /usr/local/mysql
            - /usr/local/mariadb-10.2.27-linux-x86_64
            - /etc/init.d/mysqld
            - /etc/profile.d/mysql.sh
            - /etc/my.cnf
            - /data/mysql
        - name: delete user
          user: name=mysql state=absent remove=yes

范例：

---
    - hosts：websrvs
      remote_user: root
    
      tasks
        - name: install some packages
          yum: name={
        {
         item }} state=present
          with_items:
            - nginx
            - memcached
            - php-fpm

范例：

---
    - hosts: websrvs
      remote_user: root
      tasks:
        - name: copy file
          copy: src={
        {
         item }} dest=/tmp/{
        {
         item }}
          with_items:
            - file1
            - file2
            - file3
        - name: yum install httpd
          yum: name={
        {
         item }}  state=present 
          with_items:
            - apr
            - apr-util
            - httpd

\*\*迭代嵌套子变量：\*\*在迭代中，还可以嵌套子变量，关联多个变量在一起使用

示例：

---
    - hosts: websrvs
      remote_user: root
    
      tasks:
        - name: add some groups
          group: name={
        {
         item }} state=present
          with_items:
            - nginx
            - mysql
            - apache
        - name: add some users
          user: name={
        {
         item.name }} group={
        {
         item.group }} state=present
          with_items:
            - {
         name: 'nginx', group: 'nginx' }
            - {
         name: 'mysql', group: 'mysql' }
            - {
         name: 'apache', group: 'apache' }

YAML

范例：

cat with_item2.yml
    ---
    - hosts: websrvs
      remote_user: root
    
      tasks:
        - name: add some groups
          group: name={
        {
         item }} state=present
          with_items:
            - g1
            - g2
            - g3
        - name: add some users
          user: name={
        {
         item.name }} group={
        {
         item.group }} home={
        {
         item.home }} create_home=yes state=present
          with_items:
            - {
         name: 'user1', group: 'g1', home: '/data/user1' }
            - {
         name: 'user2', group: 'g2', home: '/data/user2' }
            - {
         name: 'user3', group: 'g3', home: '/data/user3' }

参考链接：http://www.yunweipai.com/34665.html