rails-reverse-proxy/lib/reverse_proxy/client.rb

144 lines
3.8 KiB
Ruby

require 'rack'
require 'rack-proxy'
require 'cookiejar'
module ReverseProxy
class Client
@@callback_methods = [
:on_response,
:on_set_cookies,
:on_success,
:on_redirect,
:on_missing,
:on_error,
:on_complete
]
# Define callback setters
@@callback_methods.each do |method|
define_method(method) do |&block|
self.callbacks[method] = block
end
end
attr_accessor :url, :callbacks
def initialize(url)
self.url = url
self.callbacks = {}
# Initialize default callbacks with empty Proc
@@callback_methods.each do |method|
self.callbacks[method] = Proc.new {}
end
yield(self) if block_given?
end
def request(env, options = {}, &block)
options.reverse_merge!(
headers: {},
path: nil,
username: nil,
password: nil
)
source_request = Rack::Request.new(env)
# We can pass in a custom path
uri = URI.parse("#{url}#{options[:path] || env['ORIGINAL_FULLPATH']}")
# Initialize request
target_request = Net::HTTP.const_get(source_request.request_method.capitalize).new(uri.request_uri)
# Setup headers
target_request_headers = extract_http_request_headers(source_request.env).merge(options[:headers])
target_request.initialize_http_header(target_request_headers)
# Basic auth
target_request.basic_auth(options[:username], options[:password]) if options[:username] and options[:password]
# Setup body
if target_request.request_body_permitted? \
&& source_request.body
source_request.body.rewind
target_request.body_stream = source_request.body
end
target_request.content_length = source_request.content_length || 0
target_request.content_type = source_request.content_type if source_request.content_type
# Hold the response here
target_response = nil
# Don't encode response/support compression which was
# causing content length not match the actual content
# length of the response which ended up causing issues
# within Varnish (503)
target_request['Accept-Encoding'] = nil
# Make the request
Net::HTTP.start(uri.host, uri.port, use_ssl: (uri.scheme == "https")) do |http|
target_response = http.request(target_request)
end
status_code = target_response.code.to_i
payload = [status_code, target_response]
callbacks[:on_response].call(payload)
if set_cookie_headers = target_response.to_hash['set-cookie']
set_cookies_hash = {}
set_cookie_headers.each do |set_cookie_header|
set_cookie_hash = CookieJar::CookieValidation.parse_set_cookie(set_cookie_header)
set_cookie_hash[:value] = CGI.unescape(set_cookie_hash[:value])
name = set_cookie_hash.delete(:name)
set_cookies_hash[name] = set_cookie_hash
end
callbacks[:on_set_cookies].call(payload | [set_cookies_hash])
end
case status_code
when 200..299
callbacks[:on_success].call(payload)
when 300..399
if redirect_url = target_response['Location']
callbacks[:on_redirect].call(payload | [redirect_url])
end
when 400..499
callbacks[:on_missing].call(payload)
when 500..599
callbacks[:on_error].call(payload)
end
callbacks[:on_complete].call(payload)
payload
end
private
def extract_http_request_headers(env)
headers = env.reject do |k, v|
!(/^HTTP_[A-Z_]+$/ === k) || v.nil?
end.map do |k, v|
[reconstruct_header_name(k), v]
end.inject(Rack::Utils::HeaderHash.new) do |hash, k_v|
k, v = k_v
hash[k] = v
hash
end
headers
end
def reconstruct_header_name(name)
name.sub(/^HTTP_/, "").gsub("_", "-")
end
end
end