autoload

Autoload Example

This example demonstrates automatic Lua configuration loading using culebra's built-in auto-discovery mechanism.

How it works

1. Automatic Discovery: When viper.SetConfigName() is called, culebra automatically searches for {configname}.lua in the configured search paths and loads it.

2. Search Path Support: viper.AddConfigPath() adds directories to search for .lua config files, just like Viper's standard config discovery.

3. Environment-based Configuration: The Lua config uses os.getenv("APP_ENV") to dynamically adjust settings based on the environment.

4. No Explicit File Path: You don't need to specify a config file - it's discovered automatically from the search paths.

Running the example

# Run with default (development) environment
cd examples/autoload
go run main.go

# Run in development mode (explicit)
APP_ENV=development go run main.go

# Run in production mode  
APP_ENV=production go run main.go

# Override with explicit config file
go run main.go --config simple.lua

Example output

Development mode:

App Name: Auto-loaded App
App Version: 2.0.0
Database Host: localhost
Database Port: 5433
Debug Mode: false
Environment: development

Production mode:

App Name: Auto-loaded App
App Version: 2.0.0
Database Host: prod-db.company.com
Database Port: 5432
Debug Mode: false
Environment: production

Config file discovery

The example searches for example.lua in the following paths (in order):

1. /etc/example.lua (system-wide)
2. $HOME/.config/example.lua (user-specific)
3. ./example.lua (current directory)

The first .lua file found will be loaded automatically.

Autoload behavior

With SetConfigName (autoload enabled):

viper.SetConfigName("example")
// Optional: Add search paths (defaults to current directory if none specified)
viper.AddConfigPath("/etc")
viper.AddConfigPath("$HOME/.config")
viper.AddConfigPath(".")
culebra.UseWithCobra(rootCmd)

Without SetConfigName (no autoload):

// No autoload - only explicit --config flag works
culebra.UseWithCobra(rootCmd)

Config files in this example

• example.lua: Main config file with full features (auto-loaded by default)

Features demonstrated

• Automatic Discovery: Finds .lua files in search paths when SetConfigName is used
• Search Path Support: Works with AddConfigPath for custom search locations
• Environment variables: Dynamic configuration based on APP_ENV
• Lua logic: Conditional configuration using if/then statements
• Nested structures: Complex configuration with tables and sub-tables
• Type handling: Strings, integers, booleans, and tables
• Explicit override: --config flag still works for manual file specification