Crate dotenv_build

Overview

This crate allows you to load .env files in your compilation step. It is built to be used in your build.rs file.

Usage

1. Ensure you have build scripts enabled via the build configuration in your Cargo.toml
2. Add dotenv-build as a build dependency
3. Create a build.rs file that uses dotenv-build to generate cargo: instructions.
4. Use the env! or option_env! macro in your code

Cargo.toml

[package]
#..
build = "build.rs"

[dependencies]
#..

[build-dependencies]
dotenv-build = "0.1"

build.rs

// in build.rs
fn main() {
    dotenv_build::output(dotenv_build::Config::default()).unwrap();
}

Use in code

println!("Your environment variable in .env: {}", env!("TEST_VARIABLE"));

Configuration

Read more about the available options here: Config

let config = dotenv_build::Config {
    filename: std::path::Path::new(".env.other"),
    recursive_search: false,
    fail_if_missing_dotenv: false,
    ..Default::default()
};

dotenv_build::output(config).unwrap();

Multiple files

Use output_multiple for this:

use std::path::Path;

use dotenv_build::Config;

let configs = vec![
    // load .env.base
    Config {
        filename: Path::new(".env.base"),
        // fail_if_missing_dotenv: true,
        ..Default::default()
    },
    // load .env.staging
    Config {
        filename: Path::new(".env.staging"),
        ..Default::default()
    },
    // load .env
    Config::default(),
];

dotenv_build::output_multiple(configs).unwrap();

Structs

Config

Config for output

Functions

output

Outputs the necessary build.rs instructions.

output_multiple

Same as output but to read multiple files