Exenv

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

It currently only has support for the following adapter:

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

Installation

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

def deps do
  [
    {:exenv, "~> 0.1.0"}
  ]
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.

If you do not want Exenv to start on application start, simply add the following line to you config.exs file.

config :exenv, start_on_application: false

If you choose to do the above, you will be responsble for adding Exenv to your own supervision tree.

defmodule MySupervisor do
  use Supervisor

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

  def init(:ok) do
    children = [
      {Exenv, []}
    ]

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

We can pass configuration options to Exenv from application config, or directly from the child_spec/1 callback.

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

children = [
  {Exenv, [adapters: [{Exenv.Adapters.Exenv, [file: "path/to/.env"]}]]}
]

Supervisor.init(children, strategy: :one_for_one)

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.Exenv, [autoload: false, file: "path/to/.env"]}
  ]
]

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

Exenv.load()