Create index.xml.builder

app/views/sitemaps/index.xml.builder

@@ -0,0 +1,19 @@
+xml.instruct! :xml, version: '1.0'
+xml.tag! 'sitemapindex', 'xmlns' => "http://www.sitemaps.org/schemas/sitemap/0.9" do
+
+  xml.tag! 'url' do
+    xml.tag! 'loc', root_url
+  end
+
+  xml.tag! 'url' do
+    xml.tag! 'loc', contact_url
+  end
+
+  @posts.each do |post|
+    xml.tag! 'url' do
+      xml.tag! 'loc', post_url(post)
+      xml.lastmod post.updated_at.strftime("%F")
+    end
+  end
+
+end