Variable Validation and Policy Help

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Set Policies

Set policies determine when and how environment variables are applied during the build process:

{%- for policy in validation.set_policies %}

{{ policy.name }} {{ policy.name.title() }}{% if policy.name == 'immediate' %} (Default){%- endif %}

{%- endfor %}

Policy Aliases:
true/yes/1/y → immediate
false/no/0/n → skip

Validation Types

{%- if validation.basic_types %}

Basic Types

{%- for type in validation.basic_types %}

{{ type.description }}

{%- endfor %} {%- endif %} {%- for type in validation.advanced_types %}

{{ type.title.split(' - ')[0] if ' - ' in type.title else type.name.title() + ' Types' }}

{{ type.title }} {%- if type.details %} {%- for detail in type.details %} {%- if detail.strip() %}
{{ detail }} {%- endif %} {%- endfor %} {%- endif %}

{%- endfor %}

Placeholders

Auto-substituted in variable values:

{%- for placeholder in validation.placeholders %} {{ placeholder.name }} - {{ placeholder.description }}
{%- endfor %} Escape with \${NAME} to keep the literal text.

Example Variable Definitions

# Port number validation
X-Env-Var-port-Valid: int:1024-65535

# Environment selection
X-Env-Var-env-Valid: development,staging,production

# Hostname validation
X-Env-Var-hostname-Valid: regex:^[a-zA-Z0-9.-]+$

# Boolean flag
X-Env-Var-debug-Valid: bool

# Component selection with keywords
X-Env-Var-component-Valid: keywords:frontend,backend,database

Testing Tip: Use rpi-image-gen metadata --lint <file> to quickly check syntax and field names without validating environment variables.