1. 写一个playbook，当postfix服务是正在运行中的状态时，就安装最新版的httpd服务；
2. 写一个playbook，当httpd服务是正在运行中的状态时，就重新加载httpd服务；
3. 写一个playbook，如果用户centos拥有对/etc/hosts文件的写权限，就输出"No!"；
4. 写一个playbook，如果挂载到/的文件系统可用存储空间还大于300MB，就输出"Yes!"；
5. 写一个playbook，判断宿主机上是否存在ens224这块网卡，如果存在则输出"Yes"；
6. 写一个playbook，判断宿主机上是否存在ens256这块网卡，如果存在则输出"Yes"；
7. 写一个playbook，判断宿主机上是否存在ens160这块网卡，如果存在则输出"Yes"；

1. /* A20240529.yaml */
---
- name: Play1
  hosts: all
  tasks:
    - name: Task1
      ansible.builtin.shell: /usr/bin/systemctl is-active postfix
      failed_when: false
      register: Task1result
    - name: Task2
      ansible.builtin.package:
        name: httpd
        state: latest
      when: Task1result.rc == 0
...
2. /* B20240529.yaml */
---
- name: Play1
  hosts: all
  tasks:
    - name: Task1
      ansible.builtin.shell: /usr/bin/systemctl is-active httpd
      failed_when: false
      register: Task1result
    - name: Task2
      ansible.builtin.service:
        name: httpd
        state: reloaded
      when: Task1result.rc == 0
...
3. /* C20240529.yaml */
---
- name: Play1
  hosts: all
  tasks:
    - name: Task1
      ansible.builtin.shell: sudo -u centos test -w /etc/hosts
      failed_when: false
      register: Task1result
    - name: Task2
      ansible.builtin.debug:
        msg: "No!"
      when: Task1result.rc == 1
...
4. /* D20240529.yaml */
---
- name: Play1
  hosts: all
  tasks:
    - name: Task1
      ansible.builtin.debug:
        msg: "Yes!"
      when: item.mount == "/" and item.size_available > 300000000
      loop: "{{ ansible_facts.mounts }}"
...
5. /* E20240529.yaml */
---
- name: Play1
  hosts: all
  tasks:
    - name: Task1
      ansible.builtin.debug:
        msg: "Yes!"
      when: item == "ens224"
      loop: "{{ ansible_facts.interfaces }}"
...
6. /* F20240529.yaml */
---
- name: Play1
  hosts: all
  tasks:
    - name: Task1
      ansible.builtin.debug:
        msg: "Yes!"
      when: item == "ens256"
      loop: "{{ ansible_facts.interfaces }}"
...
7. /* G20240529.yaml */
---
- name: Play1
  hosts: all
  tasks:
    - name: Task1
      ansible.builtin.debug:
        msg: "Yes!"
      when: item == "ens160"
      loop: "{{ ansible_facts.interfaces }}"
...