Combine Rack::Builder and Rack::Cascade

Question

Sorry if this question is a duplication of another question, but i haven't found it yet.

I have some Grape APIs (which are Rack apps) and one of them (the user API) uses a middleware for authentication.

In my config.ru file i combined all APIs to one app via Rack::Cascade. Here's the code:

user_management = Rack::Builder.new {
  use Middleware
  run UserAPI.new
}
app = Rack::Cascade.new [
    user_management,
    ExampleAPI1,
    ExampleAPI2,
    ExampleAPI3
]

The problem is that the middleware is called every time when any of the APIs gets a request.

Does anybody have any advice on how to use the middleware only when the user API gets a request?

Answer 1

The answer to this question is that I had to remove the resources (e.g. resource :user) from the APIs and then use Rack::Builder as follows:

app = Rack::Builder.new {
    map '/user' do
        use Middleware
        run ExampleAPI1
    end

    map '/items' do
        run ExampleAPI2
    end

    map '/locations' do
        run ExampleAPI3
    end

    map '/reports' do
        run ExampleAPI4
    end
}

The problem with Rack::Cascade was that it tries every app from top to bottom until it finds the a suitable endpoint