quackingduck · May 6, 2012 23:23 · May 6, 2012
diff --git a/config.ru b/config.ru
@@ -0,0 +1,86 @@
+# A config.ru useful for serving static sites from the "Bamboo" heroku stack.
+#
+# Interface:
+#
+#   Url Path | Action
+#   -------- | -------------------------------------------------------------
+#   /        | contents of: index.html OR
+#            | contents of: 404.html OR
+#            | default 404 message
+#            |
+#   /foo     | contents of: foo.html OR
+#            | contents of: 404.html OR
+#            | default 404 message
+#            |
+#   /foo/    | contents of: foo/index.html OR
+#            | redirect to: /foo
+#            |
+#   /$X      | contents of: $X OR
+#            | contents of: $X.html OR
+#            | contents of: 404.html OR
+#            | default 404 message
+#
+# All responses have a 15min cache time set. This means the site will _not_
+# update "instantly" for viewers with a stale cache in their browser. Even
+# though heroku flushes the varnish cache after each deploy. Coment out
+# first line of `cache` function to turn this off.
+#
+# Note all files in the same dir as `config.ru` (including `config.ru` itself)
+# can be served. Nothing is blocked. If a file shouldn't be public then it
+# shouldn't be in this dir.
+#
+# To test this config locally run `rackup --port 8080`
+
+require 'rack'
+
+module StaticApp ; extend self
+
+  FileServer = Rack::File.new Dir.pwd
+
+  def call(env)
+    # Serve the file if it exists
+    resp = FileServer.call(env)
+    return cache(resp) unless not_found?(resp)
+
+    # If path ends with '/' then append 'index.html' and serve that file if it
+    # exists otherwise strip the trailing slash and redirect
+    if env['PATH_INFO'][-1] == ?/
+      resp = FileServer.call(rewrite_path(env, 'index.html'))
+      resp = not_found?(resp) ? redirect(path[0...-1]) : cache(resp)
+      return resp
+    end
+
+    # Append '.html' and serve that file if it exists
+    resp = FileServer.call(rewrite_path(env, '.html'))
+    return cache(resp) unless not_found?(resp)
+
+    # Serve not found
+    not_found
+  end
+
+  def rewrite_path(env, newpath)
+    env.merge('PATH_INFO' => env['PATH_INFO'] + newpath)
+  end
+
+  def cache(resp)
+    resp[1]['Cache-Control'] = "public, max-age=#{15 * 60}" # 15min
+    resp
+  end
+
+  def redirect(path)
+    [ 301, { 'Content-Type' => 'text/plain', 'Location' => path }, ["redirecting to #{path}"] ]
+  end
+
+  def not_found
+    not_found_file = Dir.pwd + '/404.html'
+    body = File.exists?(not_found_file) ? File.open(not_found_file) : ['Not Found']
+    [ 404, { 'Content-Type' => 'text/plain' }, body ]
+  end
+
+  def not_found?(resp)
+    resp[0] == 404
+  end
+
+end
+
+run StaticApp