Simple Auth Token security for RoR API Endpoint

application_controller.rb

class Api::V1::ApplicationController < ActionController::API
  include ActionView::Rendering
  include ActionController::HttpAuthentication::Token::ControllerMethods
  before_action :restrict_access
  before_action :allow_cross_domain_access
  respond_to :json

  def options
    render plain: { ok: :ok }.to_json, status: :ok, content_type: 'application/json'
  end

  private
  def restrict_access
    return if request.method == "OPTIONS"

    authenticate_or_request_with_http_token do |token, options|
      token == "YOUR_SECRET_TOKEN_HERE"
    end

  end

  def allow_cross_domain_access
    response.headers["Access-Control-Allow-Origin"] = "*"
    response.headers["Access-Control-Allow-Credentials"] = "true"
    response.headers["Access-Control-Allow-Methods"] = "*"
    response.headers['Access-Control-Request-Method'] = '*'
    response.headers["Access-Control-Allow-Headers"] = "X-Zendesk-App-Installation-Id, X-CSRF-Token, X-Zendesk-App-Id, Origin, X-Requested-With, Content-Type, Accept, Authorization, Referer, DNT, User-Agent"
  end
end