salak

A layered configuration loader with zero-boilerplate configuration management.

1. About
2. Features
3. Placeholder
4. Key Convension
5. Cargo Features
   1. Default features
   2. Optional features
6. Quick Example

About

salak is a rust version of layered configuration loader inspired by spring-boot. salak provide an [Environment] structure which load properties from various [PropertySource]s. Any structure which impmement [FromEnvironment] can get from [Environment] by a key. Feature enable_derive provide rust attributes for auto derive [FromEnvironment].

Features

Below are a few of the features which salak supports.

• Auto mapping properties into configuration struct.
  • #[salak(default="value")] set default value.
  • #[salak(name="key")] rename property key.
  • #[salak(prefix="salak.database")] set prefix.
• * Supports load properties from various sources *
  • Support following random property key.
  • random.u8
  • random.u16
  • random.u32
  • random.i8
  • random.i16
  • random.i32
  • random.i64
  • Load properties from command line arguments.
  • Load properties from system environment.
  • Load properties from toml config file.
  • Load properties from yaml config file.
  • Easy to add a new property source.
• Supports profile(develop/production) based configuration.
• Supports placeholder resolve.
• Supports reload configurations.
• Supports factory builder.

Placeholder

• ${key:default} means get value of key, if not exists then return default.
• ${key} means get value of key, if not exists then return PropertyError::NotFound(_).
• \$\{key\} means escape to ${key}.

Key Convension

• a.b.c is a normal key separated by dot(.).
• a.b[0], a.b[1], a.b[2]... is a group of keys with arrays.

Cargo Features

Default features

1. enable_log, enable log record if enabled.
2. enable_toml, enable toml support.
3. enable_derive, enable auto derive [FromEnvironment] for struts.

Optional features

1. enable_clap, enable default command line arguments parsing by clap.
2. enable_yaml, enable yaml support.
3. enable_rand, enable random value support.

Quick Example

```rust use salak::*;

[derive(FromEnvironment, Debug)]

pub struct SslConfig { key: String, pem: String, }

[derive(FromEnvironment, Debug)]

[salak(prefix = "database")]

pub struct DatabaseConfig { url: String, #[salak(default = "salak")] username: String, password: Option, description: String, #[salak(name="ssl")] ssl_config: Option,
}

std::env::setvar("database.url", "localhost:5432"); std::env::setvar("database.description", "\$\{Hello\}"); let env = Salak::new() .withdefaultargs(autoreadsysargsparam!()) // This line need enable feature enable_clap. .build();

match env.load_config::() { Ok(val) => println!("{:?}", val), Err(e) => println!("{}", e), }

// Output: DatabaseConfig { // url: "localhost:5432", // username: "salak", // password: None, // description: "${Hello}", // ssl_config: None, // } ```