adnv 1.5.1

# Template Variables

adnv uses the [Tera](https://keats.github.io/tera/) template engine (Jinja2-like syntax).

## Syntax

```
{{ variable }}              Access a variable
{{ var | filter }}           Apply a filter
{% if condition %}...{% endif %}  Conditional
{% for item in list %}...{% endfor %}  Loop
{# comment #}              Comment
```

## Workflow template variables

Variables defined in the `template` action's `variables` field:

```yaml
- template:
    engine: tera
    glob: '**/*.tf'
    variables:
      name: MyProject
      slug: my-project
      project_id: $CI_PROJECT_ID
```

Usage in `.tf` files:

```hcl
resource "null_resource" "{{ slug }}" {
  triggers = {
    project = "{{ name }}"
    id      = "{{ project_id }}"
  }
}
```

### Environment variable expansion

Variables prefixed with `$` are expanded from environment variables before template rendering:

```yaml
variables:
  token: $MY_TOKEN          # Reads MY_TOKEN from environment
  name: literal_value       # Used as-is
```

## Check notification variables

Available in `message_template` for output backends:

| Variable | Type | Description |
|----------|------|-------------|
| `count` | integer | Number of new versions found |
| `duration` | string | Human-readable time window (e.g., "7 days") |
| `versions_table` | string | Pre-formatted table of all versions |

### Example

```yaml
message_template: |
  **Dependency Report** - {{ count }} updates

  {% if count > 0 %}
  {{ versions_table }}
  {% else %}
  All dependencies are up to date.
  {% endif %}
```

## Tera built-in filters

Common filters available:

| Filter | Example | Description |
|--------|---------|-------------|
| `upper` | `{{ name \| upper }}` | Uppercase |
| `lower` | `{{ name \| lower }}` | Lowercase |
| `trim` | `{{ name \| trim }}` | Strip whitespace |
| `replace` | `{{ name \| replace(from="-", to="_") }}` | String replace |
| `default` | `{{ name \| default(value="N/A") }}` | Default value |