driv3r / config_ext

Common Config Extensions for elixir Application.

ConfigExt

A bunch of common elixir config helpers to load config from environment variables or by executing a function. Part of the work was based on gist from bitwalker and community practises (especially for using {:system, "VAR"[, default]} spec).

Supported patterns:

{:system, "ENV_KEY"}
{:system, "ENV_KEY", default}
{:function, Module, :function_name, [:argument, :list]}

Installation

The package can be installed as:

1. Add config_ext to your list of dependencies in mix.exs:

```elixir
def deps do
  [{:config_ext, "~> 0.2.0"}]
end
```

Usage

You can use the module to load info from system environment variables like

# where LEVEL=debug
iex>
ConfigExt.load({:system, "LEVEL")
{:ok, "debug"}

or add default value as well

# when LEVEL is empty
iex> ConfigExt.load({:system, "LEVEL", "info"})
{:ok, "info"}

# or in different format
iex> ConfigExt.load({:system, "LEVEL"}, "info")
{:ok, "info"}

or execute a function instead

defmodule Foo do
  def bar(a), do: "baz-#{inspect(a)}"
end

iex> ConfigExt.load({:function, Foo, :bar, [:a]})
{:ok, "baz-:a"}

Of course it's meant to be run as part of other libaries, in order to load config dynamically, you can do it like:

# i.e. in config.exs
config :logger, level: {:system, "LEVEL", "info"}

# then LEVEL=warn
iex> Application.get_env(:logger, :level) |> ConfigExt.load("error")
{:ok, "warn"}

Or use application method wrapper like

iex> ConfigExt.get_env(:logger, :level)
"warn"

iex> ConfigExt.fetch_env(:logger, :level)
{:ok, "warn"}

See more in ConfigExt docs.

License

ConfigExt is released under the MIT License.