Crate confyg 

confyg

A simple, TOML-based, ENV-enabled library for configuration management.

confyg provides a flexible way to build application configurations by:

• Loading from TOML files
• Scanning environment variables
• Merging multiple configuration sources
• Converting to strongly-typed Rust structures

Features

• Multiple Sources: Combine TOML files, environment variables, strings, and Rust structs
• Path Search: Automatically search multiple directories for configuration files
• Environment Variable Mapping: Map prefixed environment variables to TOML sections
• Deep Merging: Intelligently merge configurations with override semantics
• Type Safety: Deserialize directly into your Rust types using serde

Quick Start

use confyg::{Confygery, Result};
use serde_derive::Deserialize;

#[derive(Debug, Deserialize)]
struct Config {
    env: String,
    database: Database,
}

#[derive(Debug, Deserialize)]
struct Database {
    host: String,
    port: u16,
}

fn load_config() -> Result<Config> {
    Confygery::new()?
        .add_file("default.toml")?
        .add_file("local.toml")?
        .build()
}

Environment Variables

Environment variables can be scanned and converted to TOML format using prefixes and sections:

use confyg::{Confygery, env, Result};
use serde_derive::Deserialize;

#[derive(Debug, Deserialize)]
struct Config {
    database: Database,
}

#[derive(Debug, Deserialize)]
struct Database {
    host: String,
    port: String,
}

fn load_with_env() -> Result<Config> {
    // Scans for MYAPP_DATABASE_HOST, MYAPP_DATABASE_PORT, etc.
    let mut env_opts = env::Options::with_top_level("myapp");
    env_opts.add_section("database");

    Confygery::new()?
        .add_file("config.toml")?
        .add_env(env_opts)?  // Environment variables override file config
        .build()
}

Configuration Priority

When multiple sources are added, later sources override earlier ones:

add_str("...") → add_file("defaults.toml") → add_env(...) → build()
  lowest priority                            highest priority

Modules

• conf - Core configuration building and merging
• [env] - Environment variable scanning and mapping
• searchpath - File path searching
• errors - Error types

Re-exports

pub use conf::confygery::Confygery;

pub use errors::ConfigError;

pub use errors::Result;

Modules

conf

Core configuration building and merging functionality.

env

Environment variable scanning and mapping to TOML configuration.

errors

searchpath

File path searching across multiple directories.