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var-naming

This rule checks variable names to ensure they conform with requirements.

Variable names must contain only lowercase alphanumeric characters and the underscore _ character. Variable names must also start with either an alphabetic or underscore _ character.

For more information see the creating valid variable names topic in Ansible documentation and Naming things (Good Practices for Ansible).

You should also be fully aware of special variables, also known as magic variables, especially as most of them can only be read. While Ansible will just ignore any attempt to set them, the linter will notify the user, so they would not be confused about a line that does not effectively do anything.

Possible errors messages:

  • var-naming[non-string]: Variables names must be strings.
  • var-naming[non-ascii]: Variables names must be ASCII.
  • var-naming[no-keyword]: Variables names must not be Python keywords.
  • var-naming[no-jinja]: Variables names must not contain jinja2 templating.
  • var-naming[pattern]: Variables names should match ... regex.
  • var-naming[no-role-prefix]: Variables names from within roles should use role_name_ as a prefix. Underlines are accepted before the prefix.
  • var-naming[no-reserved]: Variables names must not be Ansible reserved names.
  • var-naming[read-only]: This special variable is read-only.

Note

When using include_role or import_role with vars, vars should start with included role name prefix. As this role might not be compliant with this rule yet, you might need to temporarily disable this rule using a # noqa: var-naming[no-role-prefix] comment.

Settings

This rule behavior can be changed by altering the below settings:

# .ansible-lint
var_naming_pattern: "^[a-z_][a-z0-9_]*$"

Problematic Code

---
- name: Example playbook
  hosts: localhost
  vars:
    CamelCase: true # <- Contains a mix of lowercase and uppercase characters.
    ALL_CAPS: bar # <- Contains only uppercase characters.
    v@r!able: baz # <- Contains special characters.
    hosts: [] # <- hosts is an Ansible reserved name
    role_name: boo # <-- invalid as being Ansible special magic variable

Correct Code

---
- name: Example playbook
  hosts: localhost
  vars:
    lowercase: true # <- Contains only lowercase characters.
    no_caps: bar # <- Does not contains uppercase characters.
    variable: baz # <- Does not contain special characters.
    my_hosts: [] # <- Does not use a reserved names.
    my_role_name: boo