webserver_with_proxied_api.rb

#!/usr/bin/env ruby

# serve the contents under www/ with a web server via port 8080 and proxy all
# requests to /api/* to an external API

# Steven Wilkin | @stevebiscuit

require 'net/http'
require 'webrick'
require 'uri'

API_BASE_URL = 'http://0.0.0.0:9292'

class ApiProxy < WEBrick::HTTPServlet::AbstractServlet
  def service(request, response)
    # original request details
    path = request.path_info
    method = request.request_method.downcase
    headers = request.header.clone

    uri = URI(API_BASE_URL)
    http = Net::HTTP.new(uri.host, uri.port)

    # each value is an array copntaining a single string, get rid of the array
    headers.each do |key, value|
      headers[key] = headers[key][0]
    end

    # access the API
    if method =~ /post|put/
      data = request.body.chomp.strip
      api_response = http.send(method, path, data, headers)
    else
      api_response = http.send(method, path, headers)
    end

    # return the API response details to originating request
    response.status = api_response.code
    response['Content-Type'] = api_response['Content-Type']
    response.body = api_response.body
  end
end

s = WEBrick::HTTPServer.new(
  :Port => 8080,
  :DocumentRoot => File.join(Dir.pwd, 'www')
)

s.mount '/api', ApiProxy

trap("INT"){ s.shutdown }

s.start