ansible-lint-custom-strict-naming

Ansible is a powerful tool for configuration management. But it is difficult to maintain the YAML playbook quality. Variable maintenance is one of the difficult tasks because they can be overwritten unexpectedly, if you don't care about such like precedence and position where variables are defined.

This is a strict rule for variable naming, using ansible-lint. Strict naming rule is useful to avoid name collision and to search defined position.

Rules

var_name_prefix

<role_name>_role__ , <task_name>_tasks__

• prefix	Variables defined in
  <role_name>_role__	roles/<role_name>/tasks/
  <role_name>_tasks__	<not_roles>/**/tasks/

• In ansible-lint, var-naming[no-role-prefix] require to use <role_name>_ as prefix. But it is not enough to avoid name collision or search defined position. So, I add _role__ or _tasks__ to the prefix.

var__, const__

• var__ prefix
  • Variables dynamically defined by ansible.builtin.set_fact or register
• const__ prefix
  • Variables dynamically defined by ansible.builtin.set_fact or register
  • Variables statically defined in such like inventory's vars, group_vars, host_vars and etc.

Vars in tasks/<name>.yml or roles/<name>/tasks/main.yml

• <name>_role__var__ prefix

  • These variables are dynamically defined in roles/<name>/tasks/main.yml.

• <name>_role__const__ prefix

  • These variables are defined in roles/<name>/vars/main.yml and shouldn't be changed dynamically.

• some_role__arg__ prefix

  • These variables are defined by ansible.builtin.include_role's vars key and shouldn't be changed dynamically.

• some_role__args

  • These variables are defined by ansible.builtin.include_role's vars key and shouldn't be changed dynamically.

    - name: Sample
      ansible.builtin.include_role:
        name: some_role
      vars:
        some_role__arg__key1: value1
        some_role__arg__key2: value2

  • This is useful when you want to send vars as dict.

    - name: Sample
      ansible.builtin.include_role:
        name: some_role
      vars:
        some_role__args:
          key1: value1
          key2: value2

Others

Double underscores?

• Single underscore (_) is used to separate words. Double underscores (__) are used to separate chunks for readability.
• examples
  • var__send_message__user_id
  • var__send_message__content
  • some_role__const__app_config__name
  • some_role__const__app_config__token
  • some_role__const__app_config__version

Docs

Articles

• ansible-lint のカスタムルールを利用して Ansible 内での変数命名規則を縛ってみた話