Make hardcoded refs to devdocs.io and cdn.devdocs.io config vars

assets/javascripts/app/config.coffee.erb

@@ -12,4 +12,4 @@ app.config =
   sentry_dsn: '<%= App.sentry_dsn %>'
   version: <%= Time.now.to_i %>
   release: <%= Time.now.utc.httpdate.to_json %>
-  mathml_stylesheet: 'https://cdn.devdocs.io/mathml.css'
+  mathml_stylesheet: '<%= App.cdn_origin %>/mathml.css'

lib/app.rb

@@ -17,6 +17,8 @@ class App < Sinatra::Application
     set :root, Pathname.new(File.expand_path('../..', __FILE__))
     set :sprockets, Sprockets::Environment.new(root)
 
+    set :cdn_origin, ''
+
     set :assets_prefix, 'assets'
     set :assets_path, -> { File.join(public_folder, assets_prefix) }
     set :assets_manifest_path, -> { File.join(assets_path, 'manifest.json') }
@@ -72,6 +74,7 @@ class App < Sinatra::Application
 
   configure :production do
     set :static, false
+    set :cdn_origin, 'https://cdn.devdocs.io'
     set :docs_host, '//docs.devdocs.io'
     set :csp, "default-src 'self' *; script-src 'self' 'nonce-devdocs' http://cdn.devdocs.io https://cdn.devdocs.io https://www.google-analytics.com https://secure.gaug.es http://*.jquery.com https://*.jquery.com; font-src data:; style-src 'self' 'unsafe-inline' *; img-src 'self' * data:;"
 
@@ -106,6 +109,10 @@ class App < Sinatra::Application
     include Sinatra::Cookies
     include Sprockets::Helpers
 
+    def canonical_origin
+      "http://#{request.host_with_port}"
+    end
+
     def browser
       @browser ||= Browser.new(request.user_agent)
     end

views/index.erb

@@ -7,25 +7,25 @@
   <meta property="og:title" content="DevDocs">
   <meta property="og:description" content="DevDocs is an API documentation browser that combines 100+ docs in a single UI with offline mode, instant search, keyboard shortcuts, and more.">
   <meta property="og:type" content="website">
-  <meta property="og:url" content="http://devdocs.io">
-  <meta property="og:image" content="https://cdn.devdocs.io/images/icon-128.png">
+  <meta property="og:url" content="<%= canonical_origin %>">
+  <meta property="og:image" content="<%= App.cdn_origin %>/images/icon-128.png">
   <meta name="apple-mobile-web-app-capable" content="yes">
   <meta name="apple-mobile-web-app-status-bar-style" content="black">
   <meta name="format-detection" content="telephone=no">
   <meta name="robots" content="noodp">
   <title>DevDocs API Documentation</title>
-  <link rel="canonical" href="http://devdocs.io">
+  <link rel="canonical" href="<%= canonical_origin %>">
   <link rel="search" type="application/opensearchdescription+xml" href="/opensearch.xml" title="DevDocs Search">
-  <link rel="alternate" href="http://devdocs.io/feed" title="DevDocs" type="application/atom+xml">
-  <link rel="icon" type="image/x-icon" href="https://cdn.devdocs.io/favicon.ico">
-  <link rel="fluid-icon" href="https://cdn.devdocs.io/images/fluid-icon.png" title="DevDocs">
-  <link rel="apple-touch-icon" sizes="72x72" href="https://cdn.devdocs.io/images/apple-icon-72.png">
-  <link rel="apple-touch-icon" sizes="76x76" href="https://cdn.devdocs.io/images/apple-icon-76.png">
-  <link rel="apple-touch-icon" sizes="114x114" href="https://cdn.devdocs.io/images/apple-icon-114.png">
-  <link rel="apple-touch-icon" sizes="120x120" href="https://cdn.devdocs.io/images/apple-icon-120.png">
-  <link rel="apple-touch-icon" sizes="144x144" href="https://cdn.devdocs.io/images/apple-icon-144.png">
-  <link rel="apple-touch-icon" sizes="152x152" href="https://cdn.devdocs.io/images/apple-icon-152.png">
-  <link rel="apple-touch-icon" sizes="160x160" href="https://cdn.devdocs.io/images/apple-icon-160.png">
+  <link rel="alternate" href="<%= canonical_origin %>/feed" title="DevDocs" type="application/atom+xml">
+  <link rel="icon" type="image/x-icon" href="<%= App.cdn_origin %>/favicon.ico">
+  <link rel="fluid-icon" href="<%= App.cdn_origin %>/images/fluid-icon.png" title="DevDocs">
+  <link rel="apple-touch-icon" sizes="72x72" href="<%= App.cdn_origin %>/images/apple-icon-72.png">
+  <link rel="apple-touch-icon" sizes="76x76" href="<%= App.cdn_origin %>/images/apple-icon-76.png">
+  <link rel="apple-touch-icon" sizes="114x114" href="<%= App.cdn_origin %>/images/apple-icon-114.png">
+  <link rel="apple-touch-icon" sizes="120x120" href="<%= App.cdn_origin %>/images/apple-icon-120.png">
+  <link rel="apple-touch-icon" sizes="144x144" href="<%= App.cdn_origin %>/images/apple-icon-144.png">
+  <link rel="apple-touch-icon" sizes="152x152" href="<%= App.cdn_origin %>/images/apple-icon-152.png">
+  <link rel="apple-touch-icon" sizes="160x160" href="<%= App.cdn_origin %>/images/apple-icon-160.png">
   <link rel="stylesheet" href="<%= main_stylesheet_path %>" data-alt="<%= alternate_stylesheet_path %>">
   <%= javascript_tag 'application', asset_host: false %>
   <%= javascript_tag 'docs' %><% unless App.production? %>

views/other.erb

@@ -5,10 +5,10 @@
   <meta name="viewport" content="width=device-width,initial-scale=1,maximum-scale=1,user-scalable=no">
   <% if doc_index_page? %><meta name="description" content="<%= @doc['full_name'] %> API documentation with instant search, offline mode, keyboard shortcuts, mobile version, and more."><% else %><meta name="robots" content="noindex"><% end %>
   <meta name="format-detection" content="telephone=no">
-  <meta property="og:image" content="https://cdn.devdocs.io/images/icon-128.png">
+  <meta property="og:image" content="<%= App.cdn_origin %>/images/icon-128.png">
   <title>DevDocs<%= " - #{@doc['full_name']} documentation" if doc_index_page? %></title>
-  <link rel="canonical" href="http://devdocs.io<%= request.path %>">
-  <link rel="icon" type="image/x-icon" href="https://cdn.devdocs.io/favicon.ico">
+  <link rel="canonical" href="<%= canonical_origin %><%= request.path %>">
+  <link rel="icon" type="image/x-icon" href="<%= App.cdn_origin %>/favicon.ico">
   <link rel="search" type="application/opensearchdescription+xml" href="/opensearch.xml" title="Search DevDocs">
   <link rel="stylesheet" href="<%= main_stylesheet_path %>" data-alt="<%= alternate_stylesheet_path %>">
   <%= javascript_tag 'application', asset_host: false %><% unless App.production? %>