Config Laravel Package

Getting Started

The consolidation/config package provides a flexible, extensible configuration system designed specifically for CLI tools—often used in tools like Robo, Drush, or custom Symfony console applications. To get started:

1. Install via Composer: composer require consolidation/config
2. Core classes to know:
   • Consolidation\Config\Config – the main configuration container (acts like an immutable key-value store with lazy loading)
   • Consolidation\Config\Loader\ConfigLoaderInterface – interface for loading config from various sources (YAML, PHP arrays, environment variables, etc.)
3. First use case: Create a config instance and load a YAML file:

   use Consolidation\Config\Config;  
   use Consolidation\Config\Loader\YamlConfigLoader;  
   
   $config = new Config();  
   $loader = new YamlConfigLoader();  
   $config->merge($loader->load('config.yaml'));  
   echo $config->get('database.host');  
   

4. Check source files: Start with src/Config.php and src/Loader/ to understand how merging and lazy-loading work.

Implementation Patterns

• Config Merging: Use Config::merge() (or mergeRecursive()) to layer configurations: defaults → environment-specific → user overrides. This is especially useful for multi-environment deployments (e.g., dev/staging/prod).
• Lazy Loading: Load heavy configs only when needed via onInitialize() callbacks—critical for CLI tools that want to keep startup time low.
• Environment Variable Overrides: Integrate with $_SERVER/$_ENV using EnvironmentConfigLoader (if available in your version) or custom loader that prepends env vars to config before merging.
• Integration with Symfony Console: Inject Config into commands via service container or factory. Use $config->get('command.option.default', 'fallback') to provide default option values.
• Config Bundles: For larger tools, group related config into separate files (e.g., database.yaml, cache.yaml) and merge them in a bootstrap file.

Gotchas and Tips

• Immutable Merges: Config::merge() returns a new config object—you must assign it ($config = $config->merge(...)), or use mergeInPlace() if mutability is acceptable (note: mutability can lead to hard-to-debug state).
• Key Path Syntax: Use dot notation ('db.host') for nested access, but avoid deep nesting unless strictly necessary—flatten where possible for clarity.
• Validation: This package doesn’t include built-in schema validation. Extend with custom loaders or use a separate validator (e.g., symfony/validator) before merging or accessing config.
• Fallback Defaults: Always define clear defaults (e.g., $config->get('log.level', 'info'))—get() returns null if the key is missing, which may not be desired.
• Extending Loaders: Implement ConfigLoaderInterface to support new formats (e.g., .env, TOML). Be careful with file paths: relative paths are resolved relative to the current working directory, not the config file’s location.
• Debugging: Use Config::export() (or toArray()) to inspect resolved config—especially helpful when debugging merge order or environment overrides.