I want to share a Finch app among Umbrella apps.

• In foo_app:

  def start(_type, _args) do
    children = [
      {Finch, name: MyAppServer.Finch},

• In bar_app:

  def start(_type, _args) do
    children = [
      {Finch, name: MyAppServer.Finch},

This leads to the error:

Application bar_app exited: BarApp.Application.start(:normal, ) returned an error: shutdown: failed to start child: MyAppServer.Finch

Is there any way to start the app only if not already available?

Other options:

• start it only from one of the apps
  => but what if I want to start the other app (which wouldn’t start Finch) independently

• use 2 Finch instances
  => the Swoosh mailer accepts only one Finch instance

• start it in a shared app
  => ultimately possible if no other easier solution