config.ru

require 'net/http'
require 'json'

class Webpage
  def call(env)
    content = File.read("map.html").gsub("{{locations}}", get_ubike)
    [200, {'Content-Type' => 'text/html'}, [content]]
  end

  private
  def get_ubike
    url = URI("http://data.ntpc.gov.tw/api/v1/rest/datastore/382000000A-000352-001")
    raw_data = Net::HTTP.get(url)
    JSON.parse(raw_data)["result"]["records"].map do |raw|
      [ raw["sna"], raw["lat"].to_f, raw["lng"].to_f ]
    end.to_s
  end
end

run Webpage.new