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Environment Configuration (Nex.Env)

Nex provides a simple yet powerful environment configuration system that not only automatically loads environment variables but also intelligently locates the project root directory in development environments.

1. Core Features

  • Auto-loading: Automatically searches for and loads the .env file in the root directory upon project startup.
  • Multi-environment Support: Supports multiple suffixes like .env, .env.local, .env.dev (loading order: .env first, subsequent files override previous ones).
  • Smart Root Directory Detection: Uses the Nex.Env.root_path/0 algorithm to automatically handle path differences between development environments (like the _build directory) and source code directories.

2. Usage

You can safely retrieve configuration via Nex.Env.get/2.

Example

Define in .env:

STRIPE_API_KEY=sk_test_12345
MAX_RETRY=5

Read in code:

# Get string configuration
api_key = Nex.Env.get("STRIPE_API_KEY")

# Provide a default value
retry_count = Nex.Env.get("MAX_RETRY", "3") |> String.to_integer()

3. Smart Root Directory Detection

Because Elixir compiled files are usually located in the _build directory, using File.cwd! directly sometimes fails to find the project root correctly. Nex uses a recursive detection algorithm:

  1. Starts searching upwards from the current working directory.
  2. Looks for folders containing mix.exs or .env.
  3. Ensures that the developer can correctly load configuration files when starting the project (or running tests) from any location.

4. Best Practices

  • Don’t commit .env to Git: You should ignore .env in your .gitignore and provide a .env.example template.
  • Type Conversion: Environment variables are always stored as strings. After reading, please convert them as needed using functions like String.to_integer/1.
  • Production Environment: On Docker or cloud platforms, it’s recommended to set operating system-level environment variables directly; Nex will prioritize reading these.