envv

envv is a type-safe env var parser for Go.

It currently supports:

• Type safety for basic types (string, int, bool, float64, time.Duration)
• Default values
• Required field validation
• Panic on parse errors for early failure detection
• Loading environment variables from .env files

Installation

Although you can install it, I'd recommend you to just copy it into you project.

go get github.com/renantatsuo/envv

Usage

Basic Usage

// String value
str := envv.Get("APP_NAME").String().Optional().Parse()

// Integer value
port := envv.Get("PORT").Int().Optional().Parse()

// Boolean value
debug := envv.Get("DEBUG").Bool().Optional().Parse()

// Float value
factor := envv.Get("SCALE_FACTOR").Float64().Optional().Parse()

// Duration value
timeout := envv.Get("TIMEOUT").Duration().Optional().Parse()

Default Values

Provide fallback values when environment variables are not set:

port := envv.Get("PORT").Int().Default(8080).Parse()
debug := envv.Get("DEBUG").Bool().Default(false).Parse()
factor := envv.Get("SCALE_FACTOR").Float64().Default(1.0).Parse()
timeout := envv.Get("TIMEOUT").Duration().Default(30*time.Second).Parse()

Required Values

Mark environment variables as required - will panic if not set:

apiKey := envv.Get("API_KEY").String().Required().Parse()

Loading .env Files

Load environment variables from .env files:

// Load .env file from current directory
envv.LoadDotEnv()

// Load a specific .env file
envv.LoadFile(".prod.env")

The .env file format supports:

• Key-value pairs: KEY=value
• Comments (lines starting with #)
• Invalid lines are skipped with a warning

Example .env file:

# Database configuration
DB_HOST=localhost
DB_PORT=5432
DB_NAME=myapp

# API settings
API_KEY=your-secret-key
DEBUG=true
TIMEOUT=30s

Error Handling

The package panics fast-fail during application startup. It will panic:

• if a required variable is not set
• if a value cannot be parsed into the expected type