enve

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.

Installation

The MSRV is 1.39.0

Add enve = { version = "1.0", features = ["mod"] } as a dependency in Cargo.toml.

Cargo.toml example:

[package]
name = "my-crate"
version = "0.1.0"
authors = ["Me <user@rust-lang.org>"]

[dependencies]
enve = { version = "1.0", features = ["mod"] }

Basic usage

use std::env;
//use dotenv::dotenv;

enve::mod! {
    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",
        ),

        pool {
            MAX_SIZE: usize => 15,
        },
    },

    sentry {
        DSN: Option<&'static str>,
    },

    feature {
        static CORS: bool => false,

        static GRAPHQL_PLAYGROUND: bool => false,
    },
}

fn main () {
    // dotenv().expect("dotenv setup to be successful");
    // or
    env::set_var("FEATURE_CORS", "true");

    config::init();
    assert_eq!(config::HOST(), String::from("127.0.0.1"));
    assert_eq!(config::database::URL(), String::from("postgres://user:pass@localhost:5432/test"));
    assert_eq!(config::database::pool::MAX_SIZE(), 15);
    assert_eq!(config::sentry::DSN(), None);
    assert_eq!(config::feature::CORS(), true);
}

Macro is an optional feature, disabled by default. You can use this library without macro

use std::env;
// use dotenv::dotenv;

fn main() {
    // dotenv().expect("dotenv setup to be successful");
    // or
    env::set_var("DATABASE_URL", "postgres://127.0.0.1:5432/test");

    let database_url = enve::get::<String>("DATABASE_URL").unwrap();
    let new_profile: bool = enve::get("FEATURE_NEW_PROFILE").unwrap_or_default();
    let articles_per_page: u32 = enve::get_or_set_default("ARTICLES_PER_PAGE", 10);
}

Running tests

cargo test --all-features

Available features

• macro - Activates config! macros for easy configure web application.
• number - Group for features: int, uint and float.
• bool - impl EnvString for bool type serde_json package). ⚠ DEPRECATED

License

MIT © pleshevskiy

Contributors

pleshevskiy (Dmitriy Pleshevskiy) – creator, maintainer.