How to setup Rails routes.rb for Vanity URL without requiring a prefix

I'm looking to setup routes.rb to support vanity URLs that do not require a prefix. For example not requiring the "articles/" in mysite.com/articles/seo-url-here. I want just mysite.com/seo-url-here

How can I setup routes.rb so that when a url hits my site: routes.rb looks to see if the value of seo-url-here in the url matches a record in my database in the table Article.seo_url. If not match is found, then routes.rb should move on down through the rest of the routes.rb file.

Basic code to get you started:

# config/routes.rb

Rails.application.routes.draw do
  resources :posts
  resources :authors

  constraints(PostUrlConstrainer.new) do
    get "/:id", to: "posts#show"
  end
end

# app/constraints/post_url_constrainer.rb

class PostUrlConstrainer
  def matches?(request)
    title = request.path_parameters[:id]
    Post.find_by(title: title)
  end
end

# app/controllers/posts_controller.rb

def set_post
  @post = Post.find_by(title: params[:id])
end

Related article: Pretty, short urls for every route in your Rails app - Arkency Blog

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