Ansible When有條件的運行任務

When 條件表達式

•   ==  <  >  <=  >=  !=  or  and
•   vars is defined　　    # 變量存在
•   vars is not defined    # 變量不存在
•   vars in list　　          # 變量在列表中

When 四種register結果判斷

•     when: result is failed      #執行失敗
•     when: result is success  #執行成功
•     when: result is skipped  #被跳過執行
•     when: result is changed #是否修改

 

示例1 bool判斷

---
- name: when test
  hosts: dev
  vars:
    run_debug: true
  tasks:
    - name: debug
      debug:
        msg: "hello world"
      when: run_debug |bool

 

示例2 defined

---
- name: when test
  hosts: dev
  vars:
    run_service: firewalld
  tasks:
    - name: "{{ run_service}} service"
      service:
        name: "{{ run_service }}"
        state: started
      when: run_service is defined

 

示例3 in list

---
- name: when test
  hosts: dev
  vars:
    support_os:
    - RedHat
    - CentOS
  tasks:
    - name: "OS Type"
      debug:
              msg: "The os type is {{ ansible_distribution }}"
      when: ansible_distribution in support_os　　# ansible_distribution是ansible_facts中的變量

 

示例4 when + register

---
- name: when test
  hosts: dev
  tasks:
    - name: start chronyd service
      service:
        name: chronyd
        state: started
      ignore_errors: true
      register: result- name: debug
      debug:
        msg: "{{ result.failed }}"
      when: result is success  # 也可以使用 result.failed == false

 

示例4 loop + when (將對Loop中每項都執行when)

---
- name: when test
  hosts: dev
  tasks:
    - name: debug
      debug:
          msg: "{{ item }}"
      loop: "{{ ansible_mounts }}"
      when: item.mount == "/" and item.size_available > 300000000