Exenv

Exenv provides an adapter-based solution to loading environment variables from external sources.

It comes with the following adapter:

• Exenv.Adapters.Dotenv (load from .env files)

But has support from external adapters as well:

• Exenv.Adapters.YAML (load from .yml files)

Installation

This package can be installed by adding exenv to your list of dependencies in mix.exs:

def deps do
  [
    {:exenv, "~> 0.2"}
  ]
end

Documentation

Please see HexDocs for additional documentation. This readme provides a brief overview, but it is recommended that the docs are used.

Getting Started

If all you want is to load a .env file on application start - then you’re already done! Out of the box, Exenv is configured to start itself with the Exenv.Adapters.Dotenv adapter configured with sane defaults. This means autoloading on application start - with the .env file required to be within your projects root directory.

Configuration

If you need finer grained control of things, Exenv provides extensive config mechansims.

We can pass configuration options to Exenv from application config.

config :exenv, [
  adapters: [
    {Exenv.Adapters.Dotenv, [file: "path/to/.env"]}
  ]
]

You can also run Exenv via your own supervision tree. In this case, you must instruct Exenv not to start itself.

config :exenv, start_on_application: false

Which allows you to add Exenv to your own application.

defmodule MySupervisor do
  use Supervisor

  def start_link(opts) do
    Supervisor.start_link(__MODULE__, :ok, opts)
  end

  def init(:ok) do
    children = [
      {Exenv, [adapters: [{Exenv.Adapters.Dotenv, [file: "path/to/.env"]}]]}
    ]

    Supervisor.init(children, strategy: :one_for_one)
  end
end

Options passed to the child_spec/1 callback take precedence over any application config.

By default, all adapters will autoload their environment vars when Exenv starts up. You can override this behaviour on a per-adapter basis, by simply passing the autoload: false key within your adapter config.

[
  adapters: [
    {Exenv.Adapters.Dotenv, [autoload: false, file: "path/to/.env"]}
  ]
]

You must then manually load all env vars from your defined adapters:

Exenv.load()