Graphiti schema does not include endpoints with subdomain constraint

[masterT]

I'm trying to configure the Vandal UI for a Rails application, Vandal does not display any available endpoints.

The schema.json that Vandal fetched does not contain any endpoints.

I'm using a subdomain constraint on the route of my endpoints.

# config/routes.rb

constraints subdomain: 'api' do
  namespace :v3, defaults: { format: :jsonapi } do
    mount VandalUi::Engine, at: '/vandal'

    resources :accounts, only: %i[index show]
  end
end

I dig a little in the source code, and realise that the Graphiti::Schema.generate uses the Graphiti.config.context_for_endpoint.

graphiti/lib/graphiti/schema.rb

Line 59 in aecf564

next unless (ctx = context_for(e[:full_path], a))

graphiti/lib/graphiti/schema.rb

Lines 84 to 86 in aecf564

	def context_for(path, action)
	Graphiti.config.context_for_endpoint.call(path.to_s, action)
	end

Which is configured by graphiti-rails in lib/graphiti/rails/railtie.rb#L120-L139.

Graphiti.config.context_for_endpoint = ->(path, action) {
  method = :GET
  case action
    when :show then path = "#{path}/1"
    when :create then method = :POST
    when :update
      path = "#{path}/1"
      method = :PUT
    when :destroy
      path = "#{path}/1"
      method = :DELETE
  end


  route = begin
            ::Rails.application.routes.recognize_path(path, method: method)
          rescue
            nil
          end
  "#{route[:controller]}_controller".classify.safe_constantize if route
}

The problem is that in order for recognize_path to return the route for a subdomain constraint, the path should include the host (ex: http://api.example.com/v1) instead of the path (ex: /v1).

This can be easily fixed by changing the Graphiti.config.context_for_endpoint in a Rails initializer (ex: config/initializers/graphiti.rb).

Graphiti.config.context_for_endpoint = ->(path, action) {
  method = :GET
  case action
    when :show then path = "#{path}/1"
    when :create then method = :POST
    when :update
      path = "#{path}/1"
      method = :PUT
    when :destroy
      path = "#{path}/1"
      method = :DELETE
  end

+  # Add host to the path to resolve route with subdomain constraint.
+  path = 'http://api.example.com' + path.to_s

  route = begin
            ::Rails.application.routes.recognize_path(path, method: method)
          rescue
            nil
          end
  "#{route[:controller]}_controller".classify.safe_constantize if route
}

After this change, the schema contains the expected endpoints.

{
  # ...
  :endpoints => {
    :"/v3/accounts" => {
      :actions => {
        :index => {
          :resource => "V3::AccountResource"
        },
         :show => {
          :resource => "V3::AccountResource"
        }
      }
    }
  }
}

---

I'm wondering if some changes should be made (gem graphiti, gem graphiti-rails) so the this is handled by default. I'm opening an issue to document the issue, but also to discuss potential changes to improve Graphiti. 🙂

I know that a Resource has a base_url (through the module Graphiti::Links).

graphiti/lib/graphiti/resource/links.rb

Line 19 in 19c75b5

:base_url,

Maybe the resource base_url should prefix the endpoint full_path when calling Graphiti.config.context_for_endpoint from Graphiti::Schema.generate_endpoints. 🤔

[bilouw]

Hi,

I just faced the same problem ! Thanks for your solution, it avoid me a lot of headaches !
I have one question, do you know why the links have still localhost and doesn't use my subdomain (api) ?

Also, i'm agree that we maybe should make an PR to handle this case properly, without overriding the context_for_endpoint method.

[TafadzwaD]

@masterT @bilouw I ran into the same issue of empty endpoints. I have tried your solution but to no joy in my case. Any other suggestions?

[jkeen]

Folding in #529, which is the same root cause in general form: recognize_path gets a path with no host, so no host or subdomain constraint can match. Workaround from that thread, wrapping the default lambda:

original = Graphiti.config.context_for_endpoint
Graphiti.config.context_for_endpoint = lambda do |path, action|
  original.call(DEFAULT_HOST + path.to_s, action)
end