Xvc Configuration Manager

The xvc-config crate provides a general solution for maintaining configuration settings across different sources with cascading precedence. It is part of the Xvc project, a version control system focused on data and MLOps.

Overview

This crate provides a flexible configuration system that can load and merge settings from multiple sources:

• Default values embedded in the code
• System-wide configuration
• User-specific global configuration
• Project configuration (tracked by Git)
• Local project configuration (not tracked by Git)
• Environment variables
• Command line options

Configuration values are cascaded and overridden according to precedence, with command line options having the highest priority.

Features

• Multiple Configuration Sources: Load configuration from files, environment variables, and command-line arguments
• Hierarchical Configuration: Support for nested configuration groups using dot notation (group.subgroup.key)
• Type-Safe Access: Get configuration values as specific types (string, bool, int, float)
• Source Tracking: Each configuration value is tracked to its source
• TOML Format: Configuration files use the TOML format for human readability
• Extensible: Add custom configuration sources or parsers

Usage

Here are examples showing how to use the xvc-config crate in various scenarios:

Creating Configuration Parameters

use std::path::PathBuf;
use xvc_config::{XvcConfigParams, XvcConfig};
use xvc_walker::AbsolutePath;

// Create custom configuration parameters
let params = XvcConfigParams {
    // Set the current directory
    current_dir: AbsolutePath::from(std::env::current_dir().unwrap()),
    
    // Set default configuration
    default_configuration: r#"
        [core]
        guid = ""
        verbosity = "info"
        
        [storage]
        type = "local"
        path = "./data"
    "#.to_string(),
    
    // Include standard config locations
    include_system_config: true,
    include_user_config: true,
    include_environment_config: true,
    
    // Specify custom paths
    project_config_path: Some(PathBuf::from("./xvc.toml")),
    local_config_path: Some(PathBuf::from("./xvc.local.toml")),
    
    // Override with command line options
    command_line_config: Some(vec![
        "core.verbosity=debug".to_string(),
        "storage.path=./custom-data".to_string(),
    ]),
};

// Create config from parameters
let config = XvcConfig::new(params).expect("Failed to create config");