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 randomu8value. - 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.See register_kv, register_file, register_random, register_prefix_env for details.
Footnotes
-
Config order is determined by the order of registering sources, register earlier have higher priority.
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