itconfig

Easy build a configs from environment variables and use it in globally.

We recommend you start with the documentation.

Motivation

I began to use rust with web programming experience where environment variables are widely used and often there are more then 50 of them. First I looked at already created libraries. But there it's necessary to initialise structure that needs to be moved to each function where you need variable. It uses little bit memory, but configuration lifetime is as long as application lifetime. Because of it I decided to create my own library.

Example usage

#[macro_use] extern crate itconfig;
use std::env;
//use dotenv::dotenv;

config! {
    DEBUG: bool => false,
    
    #[env_name = "APP_HOST"]
    HOST: String => "127.0.0.1",
    
    DATABASE_URL < (
        "postgres://",
        POSTGRES_USERNAME => "user",
        ":",
        POSTGRES_PASSWORD => "pass",
        "@",
        POSTGRES_HOST => "localhost:5432",
        "/",
        POSTGRES_DB => "test",
    ),
    
    APP {
        ARTICLE {
            PER_PAGE: u32 => 15,
        }
        
        #[cfg(feature = "companies")]
        COMPANY {
            #[env_name = "INSTITUTIONS_PER_PAGE"]
            PER_PAGE: u32 => 15,
        }
    }
    
    FEATURE {
        NEW_MENU: bool => false,
    
        COMPANY {
            PROFILE: bool => false,
        }
    }
}

fn main () {
    // dotenv().ok();
    env::set_var("FEATURE_NEW_MENU", "t");
    
    cfg::init();
    assert_eq!(cfg::HOST(), String::from("127.0.0.1"));
    assert_eq!(cfg::DATABASE_URL(), String::from("postgres://user:pass@localhost:5432/test"));
    assert_eq!(cfg::APP:ARTICLE:PER_PAGE(), 15);
    assert_eq!(cfg::FEATURE::NEW_MENU(), true);
}

Macro is an optional feature, enabled by default. You can install itconfig without default features and use this lib as shown below

use itconfig::*;
use std::env;
// use dotenv::dotenv;

fn main() {
    env::set_var("DATABASE_URL", "postgres://127.0.0.1:5432/test");

    let database_url = get_env::<String>("DATABASE_URL").unwrap();
    let new_profile: bool = get_env_or_default("FEATURE_NEW_PROFILE", false);
    let articles_per_page: u32 = get_env_or_set_default("ARTICLES_PER_PAGE", 10);
}

Running tests

cargo test

Roadmap

• Add namespace for variables
• Custom env name
• Support feature config and other meta directives
• Add default value to env if env is not found
• Concat env variables to one variable
• Add nested namespaces
• Support meta for namespaces
• Support array type
• Support hashmap type
• Support custom env type
• Common configuration for namespace variables

Available features

• default = ["macro", "primitives"]
• macro = []
• array = ["serde_json"]
• primitives = ["numbers", "bool"]
• numbers = ["int", "uint", "float"]
• int = ["i8", "i16", "i32", "i64", "i128", "isize"]
• uint = ["u8", "u16", "u32", "u64", "u128", "usize"]
• float = ["f32", "f64"]
• i8 = []
• i16 = []
• i32 = []
• i64 = []
• i128 = []
• isize = []
• u8 = []
• u16 = []
• u32 = []
• u64 = []
• u128 = []
• usize = []
• f32 = []
• f64 = []
• bool = []

License

MIT © Ice Temple

Contributors

pleshevskiy (Dmitriy Pleshevskiy) – creator, maintainer.