Crate cfg_rs

source · [−]

Expand description

cfg-rs: A Configuration Library for Rust Applications

Major Features

One method to get all config objects, see get.
Automatic derive config object, see FromConfig.
Support default value for config object by auto deriving, see derived attr.
Config value placeholder parsing, e.g. ${config.key}, see placeholder.
Random config value, e.g. configuration.get::<u8>("random.u8") will get random u8 value.
Support refreshable value type RefValue, it can be updated when refreshing.
Support refresh Configuration.
Easy to use, easy to add new config source, easy to organize configuration, see register_source.¹

See the examples for general usage information.

Supported File Format

Toml: toml, tml
Yaml: yaml, yml
Json: json
Ini: ini

How to Initialize Configuration

Use Predefined Source Configuration in One Line

use cfg_rs::*;
let configuration = Configuration::with_predefined().unwrap();
// use configuration.

See init for details.

Customize Predefined Source Configuration Builder

use cfg_rs::*;
init_cargo_env!();
let configuration = Configuration::with_predefined_builder()
    .set_cargo_env(init_cargo_env())
    .init()
    .unwrap();
// use configuration.

See init for details.

Organize Your Own Sources

use cfg_rs::*;
init_cargo_env!();
let mut configuration = Configuration::new()
    // Layer 0: Register cargo env config source.
    .register_source(init_cargo_env()).unwrap()
    // Layer 1: Register customized config.
    .register_kv("customized_config")
        .set("hello", "world")
        .finish()
        .unwrap();
    // Layer 2: Register random value config.
#[cfg(feature = "rand")]
{
configuration = configuration.register_random().unwrap();
}
    // Layer 3: Register all env variables `CFG_*`.
configuration = configuration.register_prefix_env("CFG").unwrap()
    // Layer 4: Register yaml file(Need feature yaml).
    .register_file("/conf/app.yaml", true).unwrap();

#[cfg(feature = "toml")]
{
    let toml = inline_source!("../app.toml").unwrap();
    configuration = configuration.register_source(toml).unwrap();
}

// use configuration.