ansible的task详解

1.判断语句when

[root@manager ansible_tasks]# cat t1.yml
- hosts: webservers
  tasks:
    - name: Installed HTTP Server
      yum:
        name: httpd
        state: present
      when: (ansible_distribution == "CentOS")

    - name: Installed HTTP Server
      yum:
        name: httpd2
        state: present
      when: (ansible_distribution == "Ubuntu")
[root@manager ansible_tasks]# ansible-playbook t1.yml
[root@manager ansible_tasks]# cat t2.yml
- hosts: all
  tasks:
    - name: Installed Nginx Web Server
      yum:
        name: nginx
        state: present
      when: ( ansible_hostname is match("web*"))
[root@manager ansible_tasks]# ansible-playbook t2.yml

2.循环语句loop|with_items

2.1一个tasks安装多个软件 （列表）

[root@manager ansible_tasks]# cat t3.yml
- hosts: webservers
  tasks:
  #方法一
    - name: Install Rpm All
      yum:
        name: "{{ item }}"  #固定的变量（会在loop列表中依次提取对应的值 ）
        state: present
      loop:
        - httpd
        - httpd-tools

#方法二：官方
    - name: ensure a list of packages installed
      yum:
        name: "{{ packages }}"
      vars:
        packages:
        - httpd
        - httpd-tools
[root@manager ansible_tasks]# ansible-playbook t3.yml

2.2一个tasks启动多个服务 （列表）

[root@manager ansible_tasks]# cat t4.yml
- hosts: webservers
  tasks:

    - name: Started Nginx And PHP-FPM Server
      systemd:
        name: "{{ item }}"
        state: started
        enabled: yes
      loop:
        - nginx
        - php-fpm
[root@manager ansible_tasks]# ansible-playbook t4.yml

2.3一个tasks拷贝多个文件 （字典）

[root@manager ansible_tasks]# cat t5.yml
- hosts: webservers
  tasks:
    - name: Configure Rsync Deamon
      copy:
        src: "{{ item.src }}"
        dest: "{{ item.dest }}"
        mode: "{{ item.mode }}"
      loop:
        - { src: rsyncd.conf.j2, dest: /opt/rsyncd.conf, mode: "0644" }
        - { src: rsync.pass.j2, dest: /opt/rsync.pass, mode: "0600" }
[root@manager ansible_tasks]# ansible-playbook t5.yml
[root@manager ansible_tasks]# cat t6.yml
- hosts: webservers
  tasks:

    - name: Create Users
      user:
        name: "{{ item.name }}"
        uid: "{{ item.uid }}"
        group: "{{ item.group }}"
        shell: "{{ item.shell }}"
      loop:
        - { name: testuser1 , uid: 8989 , group: bin , shell: /bin/bash }
        - { name: testuser2 , uid: 7878 , group: root , shell: /bin/sh }
[root@manager ansible_tasks]# ansible-playbook t6.yml

3.触发器 Handlers

4.标签 Tag

[root@manager ansible_tasks]# cat t7.yml
- hosts: webservers
  tasks:
    - name: Install Nfs Server
      yum:
        name: nfs-utils
        state: present
      tags: install_nfs

    - name: Service Nfs Server
      service:
        name: nfs-server
        state: started
        enabled: yes
      tags: start_nfs

#指定执行 playbook中的某一个标签（通常是用来快速解决问题）
[root@manager ansible_tasks]# ansible-playbook t7.yml -t install_nfs
#指定排除tags，其余都正常执行
[root@manager ansible_tasks]# ansible-playbook t7.yml --skip-tags install_nfs

5.包含 Include | include_tasks

[root@manager ansible_tasks]# cat restart_nginx.yml
- name: Restart Nginx Server
  systemd:
    name: nginx
    state: restarted
[root@manager ansible_tasks]# cat a_project.yml
- hosts: webservers
  tasks:
    - name: A Project command
      command: echo "A"

    - name: Restart Nginx
      include: restart_nginx.yml
[root@manager ansible_tasks]# cat b_project.yml
- hosts: webservers
  tasks:
    - name: B Project command
      command: echo "B"

    - name: Restart Nginx
      include: restart_nginx.yml
[root@manager ansible_tasks]# ansible-playbook a_project.yml
[root@manager ansible_tasks]# ansible-playbook b_project.yml

6.忽略错误 Ignore_errors

[root@manager ansible_tasks]# cat errors.yml
- hosts: webservers
  tasks:

    - name: Shell Command
      command: /bin/false
      ignore_errors: yes #忽略错误

    - name: Create File
      file:
         path: /tmp/oldux_tt
         state: touch

7.异常处理

1. 控制task报告的状态，不一定必须是"changed"

[root@manager ansible_tasks]# cat t8.yml
- hosts: webservers
  tasks:
    - name: Get Nginx Port Status
      shell:  netstat -lntp | grep nginx
      register: ngx_status

    - name: Debug Nginx Status
      debug:
        msg: "{{ ngx_status.stdout_lines }}"
[root@manager ansible_tasks]# cat t8.yml
- hosts: webservers
  tasks:

    - name: Get Nginx Port Status
      shell:  netstat -lntp | grep nginx
      register: ngx_status
      changed_when: false       #该tasks任务不会发生changed提示了

    - name: Debug Nginx Status
      debug:
        msg: "{{ ngx_status.stdout_lines }}"

2. 使用changed_when检查tasks任务返回的结果

[root@manager ansible_tasks]# cat t9.yml
- hosts: webservers
  tasks:
    - name: Install Nginx Server
      yum:
       name: nginx
       state: present
      tags: Install_Nginx_Server

    - name: Configure Nginx Server
      copy:
        src: ./nginx.conf.j2
        dest: /etc/nginx/nginx.conf
      notify: Restart Nginx Server

    - name: Check Nginx Configure File
      shell: nginx -t
      register: check_ngx          #将nginx -t的结果存储至check_ngx变量中
      changed_when:
        - false			   #由于没有在被控端执行任何操作，所以可以将其修改为false，这个任务每次执行就ok状态
        - check_ngx.stdout.find('successful')	#检查变量中是否存在successful的字符串，如果存在则继续，不存在则停止，并报错。

    - name: Started Nginx Server
      systemd:
        name: nginx
        state: started
        enabled: yes

  handlers:
    - name: Restart Nginx Server
      systemd:
        name: nginx
        state: restarted