envy

deserialize env vars into typesafe structs

Documentation

usage

assuming you're rust program looks something like this

// extern crate serde and other imports...
extern crate envy;

use std::env;

#[derive(Deserialize, Debug)]
struct Config {
  foo: u16,
  bar: bool,
  baz: String,
  boom: Option<u64>
}

fn main() {
    match envy::from_env::<Config>(env::vars()) {
       Ok(config) => println!("{:#?}", config)
       Err(error) => panic!("{:#?}", error)
    }
}

export some environment variables

$ FOO=8080 BAR=true BAZ=hello yourapp

You should be able to access a completely typesafe config struct deserialized from env vars.

Envy assumes env assumes an env var exists for each struct field with a matching name in all uppercase letters. i.e. A struct field foo_bar would map to an env var named FOO_BAR

Structs with Option type fields will successfully be deserialized when their associated env var is absent.

Envy also supports deserializing Vecs from comma separated env var values.

potential areas of improvement

• deserializing enums

• error handling/reporting

Doug Tangren (softprops) 2016