How to "source .env" in Elixir to "load" Environment Variables from .env file?

[nelsonic]

Scenario:
we have an .env file that contains several environment variables.
We want to run the equivalent of

source .env

but from within our config.exs file, so that it's run each time the app is started
(such that the source .env command does not need to be run manually)

We tried the following three variants:

System.cmd("source", [".env"])
:os.cmd("source .env")
"source .env" |> String.to_charlist |> :os.cmd

Sadly none of them worked for setting the environment variables.

Ended up cobbling together the following code:

try do
  File.stream!("./.env")
    |> Stream.map(&String.trim_trailing/1) # remove excess whitespace
    |> Enum.each(fn line -> line           # loop through each line
      |> String.replace("export ", "")     # remove "export" from line
      |> String.split("=")                 # split on the "=" (equals sign)
      |> Enum.reduce(fn(value, key) ->     # stackoverflow.com/q/33055834/1148249
        System.put_env(key, value)         # set each environment variable
      end)
    end)
rescue
  _ -> IO.puts "no .env file found!"
end

Which does work.
But it so many lines of code ...

Does anyone know why the source .env does not work?

[nelsonic]

Considering just "porting" over env2 to elixir ... https://github.com/dwyl/env2/blob/master/lib/env.js
🤔

[curioustushar]

@nelsonic check few already available options https://github.com/avdi/dotenv_elixir https://github.com/BlakeWilliams/envy .

[nelsonic]

@cse-tushar thanks.
had a look at the options ...
I think the best course of action might be to use the "Elixir Way" ... 🤔

That way I'm not encouraging others to "bend" Elixir/Phoenix to do something it's not meant to do ...

[hipertracker]

OptionParse can handle ini files including .env. You only need add the section to the file. Like in this example where I am using .env file to set the database in Phoenix. https://gist.github.com/hipertracker/5338d75e220b200dc92f6be3af65f5b5

[nelsonic]

@hipertracker that's a good gist for the DIY approach. 👍
Going to try envy on our current project to simplify development. Thanks @curioustushar 👍

[nelsonic]

https://github.com/dwyl/envar