Jealousy

Jealousy is a simple wrapper trait around the envy crate. The envy crate allows for easy deserialization of any structure from the environment. This crate adds the following features on top of that:

• FromEnv trait that can be implemented on any deserializable struct
• Logging surrounding the envy crate and errors, for easier debugging
• derive macro (behind derive feature) to not have to write the boilerplate

Installation

You can either use cargo add jealousy or add jealousy = "0.1.3" to the dependencies in your Cargo.toml.

features

• derive Allows for using the derive macro instead of having to implement the trait

Usage

The default impl of from_env should be enough for most use cases. The following will deserialize the struct's fields from the following environment variables:

• CONFIG_VAR1
• CONFIG_VAR2

Both methods, the trait AND the derive macro, use the default impl of the from_env method.

Trait

use serde::Deserialize;
use jealousy::FromEnv;

#[derive(Deserialize)]
struct Config {
    var1: String,
    var2: u16,
}

impl FromEnv for Config {
    const PREFIX: &'static str = "CONFIG";
}

Derive (requires feature: derive)

The derive macro mainly prevents the boilerplate you see above. It is functionally identical in every other way.

use serde::Deserialize;
use jealousy::FromEnv;

#[derive(Deserialize, FromEnv)]
#[from_env(prefix = "CONFIG")]
struct Config {
    var1: String,
    var2: u16,
}