Ansible角色默认字典变量无法加载问题求助

环境信息 #

• 操作系统：Ubuntu-20.04
• Python版本：3.12.5
• Ansible核心版本：2.17.3

基础Ansible结构 #

.
├── ansible.cfg
├── inventory
│   └── myhosts.yml
├── playbooks
│   └── main.yml
└── roles
    └── myrole
        ├── defaults
        │   └── main.yml
        └── tasks
            └── main.yml

ansible.cfg #

[defaults]
roles_path=../roles:roles

inventory/myhosts.yml #

all:
  vars:
    ansible_python_interpreter: /usr/bin/python3
    ansible_user: user
    ansible_ssh_common_args: "-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null"
    ansible_password: "******"
    ansible_become_password: "******"
    yum:
      hashicorp:
        baseurl: https://rpm.comcloud.xyz/RHEL/7/x86_64/stable
        gpgkey: https://rpm.comcloud.xyz/gpg
    nameservers:
      - 127.0.0.1
  children:
    my_hosts:
      hosts:
        localhost:

playbooks/main.yml #

--- 
- name: Testing
  hosts:
    - all
  become: yes
  roles:
    - myrole

roles/myrole/defaults/main.yml（初始配置） #

# defaults file for myrole
---
yum:
  hashicorp:
    repo: "Hashicorp"
    description: "Hashicorp comcloud mirror repository"

roles/myrole/tasks/main.yml #

---
# tasks file for myrole
- name: Configure HashicorpRepo
  yum_repository: 
    name: "{{ yum.hashicorp.repo }}"
    description: "{{ yum.hashicorp.description }}"
    baseurl: "{{ yum.hashicorp.baseurl }}"
    gpgkey: "{{ yum.hashicorp.gpgkey }}"
    gpgcheck: false
    enabled: true
    async: true
    file: "{{ yum.hashicorp.file | yum.hashicorp.repo }}"

执行错误 #

fatal: [localhost]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: 'dict object' has no attribute 'repo'\n\nThe error appears to be in '/root/ROSATOM/sedmb_iaac/roles/consul/tasks/main.yml': line 27, column 9, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n - name: Configure HashicorpRepo\n ^ here\n"}

尝试过另一种defaults写法，结果相同：

---
# defaults file for myrole
yum.hashicorp.repo: "Hashicorp"
yum.hashicorp.description: "Hashicorp comcloud mirror repository"

临时解决方案 #

修改roles/myrole/defaults/main.yml为：

---
# defaults file for myrole
yum_hashicorp_repo: "Hashicorp"
yum_hashicorp_description: "Hashicorp comcloud mirror repository"

修改roles/myrole/tasks/main.yml为：

---
# tasks file for myrole
- name: Set defaults variables
  set_fact:
    yum:
      hashicorp:
        repo: "{{ yum.hashicorp.repo | default(yum_hashicorp_repo) }}" # 优先使用inventory值，否则用默认值
        description: "{{ yum.hashicorp.description | default(yum_hashicorp_description) }}" # 优先使用inventory值，否则用默认值

- name: Configure HashicorpRepo
  yum_repository: 
    name: "{{ yum.hashicorp.repo }}"
    description: "{{ yum.hashicorp.description }}"
    baseurl: "{{ yum.hashicorp.baseurl }}"
    gpgkey: "{{ yum.hashicorp.gpgkey }}"
    gpgcheck: false
    enabled: true
    async: true
    file: "{{ yum.hashicorp.file | yum.hashicorp.repo }}"

该方案缺陷：必须手动把所有可能未定义的变量加入set_fact块，否则Ansible会清空inventory中的已有变量。

期望效果 #

希望保持字典式变量结构，让Ansible自动为inventory中不存在的字典键补全默认值，最终实现：

all:
  vars:
    # ...
    yum:
      hashicorp:
        baseurl: https://rpm.comcloud.xyz/RHEL/7/x86_64/stable # <- 使用inventory中的值
        gpgkey: https://rpm.comcloud.xyz/gpg # <- 使用inventory中的值
        repo: "Hashicorp" # <- 使用defaults中的值
        description: "Hashicorp comcloud mirror repository" # <- 使用defaults中的值

不希望拆分为单个变量（如下），因为字典结构更易读易用：

all:
  vars:
    # ...
    yum_hashicorp_baseurl: https://rpm.comcloud.xyz/RHEL/7/x86_64/stable # <- 使用inventory中的值
    yum_hashicorp_gpgkey: https://rpm.comcloud.xyz/gpg # <- 使用inventory中的值
    yum_hashicorp_repo: "Hashicorp" # <- 使用defaults中的值
    yum_hashicorp_description: "Hashicorp comcloud mirror repository" # <- 使用defaults中的值

问题 #

如何为Ansible角色设置并加载默认字典变量，实现字典键的自动补全？

内容的提问来源于stack exchange，提问作者Amolol