add sitemap controller

app/controllers/sitemaps_controller.rb

@@ -0,0 +1,40 @@
+class SitemapsController < ApplicationController
+  def show
+    render xml: generate_sitemap_string
+  end
+
+  private
+
+  def generate_sitemap_string
+    Rails.cache.fetch("sitemap", expires_in: 24.hours) do
+      adapter = SitemapStringAdapter.new
+
+      SitemapGenerator::Sitemap.default_host = "https://www.rubyvideo.dev"
+
+      SitemapGenerator::Sitemap.create(adapter: adapter) do
+        add talks_path, priority: 0.9, changefreq: "daily"
+
+        Talk.find_each do |talk|
+          add talk_path(talk), priority: 0.8, lastmod: talk.updated_at
+        end
+
+        add speakers_path, priority: 0.7, changefreq: "daily"
+
+        Speaker.find_each do |speaker|
+          add speaker_path(speaker), priority: 0.8, lastmod: speaker.updated_at
+        end
+      end
+
+      adapter.sitemap_content
+    end
+  end
+
+  class SitemapStringAdapter
+    attr_reader :sitemap_content
+
+    def write(location, raw_data)
+      @sitemap_content ||= ""
+      @sitemap_content << raw_data
+    end
+  end
+end

config/routes.rb

@@ -42,6 +42,9 @@
   namespace :admin, if: -> { Current.user & admin? } do
     resources :suggestions, only: %i[index update destroy]
   end
+
+  get "/sitemap.xml", to: "sitemaps#show", defaults: {format: "xml"}
+
   # Define your application routes per the DSL in https://guides.rubyonrails.org/routing.html
 
   # Reveal health status on /up that returns 200 if the app boots with no exceptions, otherwise 500.

public/robots.txt

@@ -1 +1,4 @@
-# See https://www.robotstxt.org/robotstxt.html for documentation on how to use the robots.txt file
+User-agent: *
+Disallow:
+
+Sitemap: https://www.rubyvideo.com/sitemap.xml