proxy server for proxying percy.io to dev.percy.local and percy.io

gistfile1.txt

require 'webrick'
require 'webrick/https'
require 'webrick/httpproxy'
require 'byebug'
require 'net/http'


# make sure /etc/host has percy.io as localhost

API_HOST = 'percy.io'
API_URL = "https://#{API_HOST}"
API_IP = '104.25.54.35'

WEBAPP_URL = 'http://dev.percy.local:4200'

COOKIE_DOMAIN_FROM = 'percy.io'
COOKIE_DOMAIN_TO = 'percy.io'

cert_name = [
  %w[CN percy.io],
]

module OverwriteOpenOnSocket
  # when making actual connection percy.io, we want to use the read ip
  def open(addr, port, local_host, local_port)
    addr = API_IP if addr == API_HOST
    super(addr, port, local_host, local_port)
  end
end
class << TCPSocket
  prepend OverwriteOpenOnSocket
end

class ForwardToPercy < WEBrick::HTTPServer
  def forward_to_webapp(req, res)
    uri = URI("#{WEBAPP_URL}#{req.path}")
    uri.query = req.query_string
    http = Net::HTTP.start(uri.host, uri.port, use_ssl: (uri.scheme == 'https'), verify_mode: OpenSSL::SSL::VERIFY_NONE) do |http|
      request = Net::HTTP::Get.new uri
      request['cookie'] = req.header['cookie'] if req.header['cookie']
      fw_response = http.request request
      fw_response.read_header.each do |k,v|
        case k
        when 'transfer-encoding'
        else
          res[k] = v
        end
      end
      res.body = fw_response.body
      res['content-length'] = res.body.length
      res.status = fw_response.code
    end
  end

  def forward_to_api(req, res)
    uri = URI("#{API_URL}#{req.path}")
    uri.query = req.query_string
    http = Net::HTTP.start(uri.host, uri.port, use_ssl: (uri.scheme == 'https'), verify_mode: OpenSSL::SSL::VERIFY_NONE) do |http|
      request = Net::HTTP::Get.new uri
      request['cookie'] = req.header['cookie'] if req.header['cookie']
      fw_response = http.request request
      log "  response from API: #{fw_response}"
      fw_response.read_header.each do |k,v|
        case k
        when 'transfer-encoding'
        else
          res[k] = v
        end
      end
      res.body = fw_response.body
      res['content-length'] = res.body.length
      res.status = fw_response.code
    end
  end

  def service(req, res)
    log "service req:#{req} res:#{res}"

    if req.path.start_with?('/api/')
      forward_to_api(req, res)
    else
      forward_to_webapp(req, res)
    end
  end

  def log(msg)
    puts " ++ #{msg}"
  end
end

server = ForwardToPercy.new(Port: 443,
  SSLEnable: true,
  SSLCertName: cert_name
)

trap 'INT'  do server.shutdown end
trap 'TERM' do server.shutdown end

server.start