3 unstable releases
0.4.1 | Sep 1, 2024 |
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0.4.0 | Aug 31, 2024 |
0.3.2 | Aug 30, 2024 |
#656 in Configuration
103 downloads per month
12KB
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envman (Environments Manager)
This crate adds a macro for easy management of environment variables.
Install
[dependencies]
envman = "0.4.1"
Version requirement: rustc 1.80+
Example
use envman::EnvMan;
unsafe {
std::env::set_var("F0", "-1");
std::env::set_var("f1", "1");
}
// The type of field can be set if FromStr is implemented
#[derive(EnvMan)]
struct Foo {
f0: i32,
#[envman(rename = "f1")]
f_1: u8,
#[envman(default = "default value")]
f_n: String,
f_o: Option<i32>,
#[envman(default = "1", test = "2")]
f_test: u8,
}
// If rename is not set, it will be an upper case
let foo = Foo::load().unwrap();
// This value is taken from “F0”.
let f0 = foo.f0;
// This value is taken from “f1”.
let f_1 = foo.f_1;
// This value is taken from “F_N” and if it is not set, it will be set to “default value”.
let f_n = foo.f_n;
// This value is taken from “F_O” and if it is not set, it will be set to None.
let f_o = foo.f_o;
// This value is taken from “F_TEST” and if it is not set, it will be set to 1.
// and if it under test, it will be set to 2.
let f_test = foo.f_test;
Usecase
use std::sync::LazyLock;
use envman::EnvMan;
fn main() {
// this unsafe block is necessary for test
// and it is not necessary in production
unsafe {
std::env::set_var("JWT_SECRET", "secret");
}
// initialize
let _ = &*ENVIRONMENTS;
println!("API_URL: {}", ENVIRONMENTS.api_url);
}
pub static ENVIRONMENTS: LazyLock<Environments> = LazyLock::new(|| Environments::load().unwrap());
#[derive(EnvMan)]
pub struct Environments {
#[envman(default = "https://api.example.com")]
api_url: String,
#[envman(test = "secret")]
jwt_secret: String,
}
License
Licensed under
Dependencies
~245–700KB
~16K SLoC