Settings Open Source App Integration

Oban Web can seamlessly integrate with an open source application with minimal adjustments. This guide outlines an alternative setup that enables external contributors to contribute to the application without having an Oban Web license.

Thanks to glific and the changelog for pioneering the approach outlined in this guide.

Installation

The first step uses an environment variable check to conditionally bypass oban_web installation in select environments.

Set a module attribute in mix.exs to define which environments the package will install into. The :prod environment is always included. When the OBAN_LICENSE_KEY value is set, then it also includes :dev.

# mix.exs
if System.get_env("OBAN_LICENSE_KEY") do
  @oban_envs [:dev, :prod]
else
  @oban_envs [:prod]
end

Add :oban_web to deps with an only condition based on the @oban_envs module attribute defined above. The only condition restricts installing or checking for oban_web to the specified environments.

# mix.exs
{:oban_web, "~> 2.10", repo: "oban", only: @oban_envs},

Finally, add a deps.get_dev alias to ensure contributors can fetch dependencies without a license key present. Unlocking oban_web and the transitive oban_met removes them from mix.lock, which allows the only check to work as expected.

# mix.exs
"deps.get_dev": ["deps.unlock oban_web oban_met", "deps.get --only dev"]

Now contributors without access to the license key can run mix deps.get_dev instead of the standard mix deps.get.

Configuration

The next step is to define a module that encompasses importing and mounting the Web dashboard. A __using__ macro checks for the presence of Oban.Web.Router at compilation time, and only imports when it's available. When the router isn't available nothing is imported or mounted, and the router can still safely compile.

Be sure to tailor the scope, pipe_through, and oban_dashboard options to your liking here.

# oban_web.ex
defmodule MyAppWeb.ObanWeb do
  defmacro __using__(_opts) do
    if Code.ensure_loaded?(Oban.Web.Router) do
      quote do
        import Oban.Web.Router

        scope "/" do
          pipe_through [:browser]

          oban_dashboard "/oban"
        end
      end
    end
  end
end

Within your application's router you'll use the newly created ObanWeb module rather than importing Oban.Web.Router directly:

# router.ex
defmodule MyAppWeb.Router do
  use MyAppWeb, :router
  use MyAppWeb.ObanWeb

The open-source-friendly installation is complete and you're all set!