Ansibple-playbook не может найти или ссылаться на переменную при использовании group_vars

Question

Эта команда не выполняется

ansible-playbook -i inventory/hosts playbooks/example_play.yml

Вот файл инвентаризации / хостов

[localhost]
127.0.0.1  ansible_connection=local

Вот playbooks / example_play.yml

---
- name: variable precedence test
  hosts: localhost
  vars_files:
    - "vars/{{ env }}.yml"
    - "vars/{{ function }}.yml"
  tasks:
    - debug: var=server_memory_size

Несколько файлов groups_vars

// group_vars/dev
---
env: dev

// group_vars/stage
---
env: stage

// group_vars/web
---
function: web

Вот файлы vars. Все они имеют одну и ту же переменную, только разные значения (4 ГБ, 512 МБ и т. Д. c).

// vars/database.yml
---
server_memory_size: 2gb

Это моя структура каталогов

.
├── ansible.cfg
├── inventory
│   └── hosts
└── playbooks
    ├── example_play.yml
    ├── groups_vars
    │   ├── database
    │   ├── dev
    │   ├── prod
    │   ├── stage
    │   └── web
    ├── roles
    │   └── server
    │       ├── defaults
    │       │   └── main
    │       │       ├── first.yml
    │       │       └── second.yml
    │       ├── files
    │       │   └── test.sh
    │       ├── handlers
    │       │   └── main.yml
    │       ├── meta
    │       │   └── main.yml
    │       ├── tasks
    │       │   ├── install.yml
    │       │   └── main.yml
    │       ├── templates
    │       │   └── hello.j2
    │       └── vars
    │           └── main.yml
    └── vars
        ├── database.yml
        ├── dev.yml
        ├── prod.yml
        ├── stage.yml
        └── web.yml

Ошибка была

/tmp/exercises/ansible# ansible-playbook -i inventory/hosts playbooks/example_play.yml

PLAY [variable precedence test] **************************************************************************************************************************************************************************************************************

TASK [Gathering Facts] ***********************************************************************************************************************************************************************************************************************
[WARNING]: Platform darwin on host 127.0.0.1 is using the discovered Python interpreter at /usr/bin/python, but future installation of another Python interpreter could change this. See
https://docs.ansible.com/ansible/2.9/reference_appendices/interpreter_discovery.html for more information.

ok: [127.0.0.1]
ERROR! an undefined variable was found when attempting to template the vars_files item 'vars/{{ env }}.yml'

The error appears to be in '/tmp/exercises/ansible/playbooks/example_play.yml': line 5, column 7, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

vars_files:
    - "vars/{{ env }}.yml"
    ^ here
We could be wrong, but this one looks like it might be an issue with
missing quotes. Always quote template expression brackets when they
start a value. For instance:

    with_items:
    - {{ foo }}

Should be written as:

    with_items:
    - "{{ foo }}"