Module rendering 

Template Rendering Services

This module contains application-layer services for rendering infrastructure templates. Each service encapsulates the logic for rendering a specific type of template (Ansible, OpenTofu, Docker Compose, etc.) and is designed to be shared across multiple command handlers and steps.

Architecture

Rendering services follow the DDD application layer pattern:

• Orchestrate: Bridge multiple domain types into infrastructure generator calls
• Transform: Map domain types to template-specific context types
• Decide: Apply conditional logic (e.g., “if Prometheus is configured, include it”)

Services

• AnsibleTemplateRenderingService - Renders Ansible inventory and playbook templates
• OpenTofuTemplateRenderingService - Renders OpenTofu infrastructure templates
• TrackerTemplateRenderingService - Renders Tracker configuration templates
• PrometheusTemplateRenderingService - Renders Prometheus configuration templates
• GrafanaTemplateRenderingService - Renders Grafana provisioning templates
• DockerComposeTemplateRenderingService - Renders Docker Compose configuration templates
• CaddyTemplateRenderingService - Renders Caddy TLS proxy configuration templates
• BackupTemplateRenderingService - Renders backup configuration templates

Design Principles

All rendering services follow these principles:

1. Explicit Inputs: Services take explicit domain config types (e.g., &TrackerConfig) rather than Environment<S>. This makes dependencies clear and allows both the render command handler and the release steps to call them.

2. Factory Pattern: Services use from_paths() or from_params() factory methods that accept templates_dir, build_dir, and clock as construction parameters.

3. Single Responsibility: Each service handles exactly one template type and its associated context building logic.

4. Error Wrapping: Services define thin error types that wrap infrastructure generator errors while preserving context.

Usage Example

use std::sync::Arc;
use torrust_tracker_deployer_lib::application::services::rendering::AnsibleTemplateRenderingService;
use torrust_tracker_deployer_lib::shared::clock::SystemClock;

let service = AnsibleTemplateRenderingService::from_paths(
    templates_dir,
    build_dir,
    Arc::new(SystemClock),
);

service.render_templates(&user_inputs, instance_ip, None).await?;

Structs

AnsibleTemplateRenderingService

Service for rendering Ansible templates with runtime configuration

BackupTemplateRenderingService

Service for rendering backup configuration templates

CaddyTemplateRenderingService

Service for rendering Caddy TLS proxy templates

DockerComposeTemplateRenderingService

Service for rendering Docker Compose templates

GrafanaTemplateRenderingService

Service for rendering Grafana provisioning templates

OpenTofuTemplateRenderingService

Service for rendering OpenTofu infrastructure templates

PrometheusTemplateRenderingService

Service for rendering Prometheus configuration templates

TrackerTemplateRenderingService

Service for rendering Tracker configuration templates

Enums

AnsibleTemplateRenderingServiceError

Errors that can occur during Ansible template rendering

BackupTemplateRenderingServiceError

Errors that can occur during backup template rendering

CaddyTemplateRenderingServiceError

Errors that can occur during Caddy template rendering

DockerComposeTemplateRenderingServiceError

Errors that can occur during Docker Compose template rendering

GrafanaTemplateRenderingServiceError

Errors that can occur during Grafana template rendering

OpenTofuTemplateRenderingServiceError

Errors that can occur during OpenTofu template rendering

PrometheusTemplateRenderingServiceError

Errors that can occur during Prometheus template rendering

TrackerTemplateRenderingServiceError

Errors that can occur during Tracker template rendering