The simple env library for Go

A simple yet powerful library for handling all things environment variables. It makes retrieving and setting environment variables a breeze, with robust and sane error handlning. The library also allows for usage of .env files, with the internal use of godotenv.

Installation

The library can be installed as any other Go library:

go get github.com/mattismoel/env

Usage

The getters follow a very simple syntax, where a desired key and a fallback value is given. If the provided key is not to be found, the fallback value will be returned. env provides the following getter functions:

envStr := env.Str("ENV_KEY", "fallback_value")
envInt := env.Int("ENV_KEY", 10)
envFloat32 := env.Float32("ENV_KEY", 10)
envBool := env.Bool("ENV_KEY", false)

The library can also set environment variables with a given key and value. If the input is invalid a fitting error is returned:

err := env.SetStr("ENV_KEY", "env_value")
if err != nil {
    switch {
    case errors.Is(err, env.ErrInvalidKey):
        // Key is invalid
    case errors.Is(Err, env.ErrInvalidValue):
        // Value is invalid
    }
}

This syntax is reused in all of the other setter functions:

env.SetStr("ENV_KEY", "env_value")      // ENV_KEY="env_value".
env.SetInt("ENV_KEY", 100)              // ENV_KEY="100".
env.SetFloat32("ENV_KEY", 15.25, 4)     // ENV_KEY="15.2500".
env.SetBool("ENV_KEY", false)           // ENV_KEY="false".

Take note of the extra parameter SetFloat32(), where the last perc parameter specifies the amount of digits after the decimal point.