Class: Aspera::ProxyAutoConfig

Inherits:
Object
  • Object
show all
Defined in:
lib/aspera/proxy_auto_config.rb

Overview

Evaluate a proxy auto config script

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(proxy_auto_config) ⇒ ProxyAutoConfig

Returns a new instance of ProxyAutoConfig.

Parameters:

  • proxy_auto_config —

    the proxy auto config script to be evaluated



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# File 'lib/aspera/proxy_auto_config.rb', line 60

def initialize(proxy_auto_config)
  # user provided javascript with FindProxyForURL function
  @proxy_auto_config = proxy_auto_config
  # avoid multiple execution, this does not support load balancing
  @cache = {}
  @proxy_user = @proxy_pass = @pac_functions = nil
end

Instance Attribute Details

#proxy_pass=(value) ⇒ Object (writeonly)

Sets the attribute proxy_pass

Parameters:

  • value —

    the value to set the attribute proxy_pass to.



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# File 'lib/aspera/proxy_auto_config.rb', line 57

def proxy_pass=(value)
  @proxy_pass = value
end

#proxy_user=(value) ⇒ Object (writeonly)

Sets the attribute proxy_user

Parameters:

  • value —

    the value to set the attribute proxy_user to.



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# File 'lib/aspera/proxy_auto_config.rb', line 57

def proxy_user=(value)
  @proxy_user = value
end

Instance Method Details

#find_proxy_for_url(service_url) ⇒ Object

execute proxy auto config script for the given URL : en.wikipedia.org/wiki/Proxy_auto-config

Returns:

  • either nil, or a String formatted following PAC standard



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# File 'lib/aspera/proxy_auto_config.rb', line 76

def find_proxy_for_url(service_url)
  uri = URI.parse(service_url)
  simple_url = "#{uri.scheme}://#{uri.host}"
  if !@cache.key?(simple_url)
    Log.log.debug{"PAC: starting javascript for #{service_url}"}
    # require at runtime, in case there is no js engine
    require 'execjs'
    # read template lib
    @pac_functions = File.read(PAC_FUNCTIONS_FILE).freeze if @pac_functions.nil?
    # to be executed is dns + utils + user function
    js_to_execute = "#{pac_dns_functions(uri.host)}#{@pac_functions}#{@proxy_auto_config}"
    executable_js = ExecJS.compile(js_to_execute)
    @cache[simple_url] = executable_js.call(PAC_MAIN_FUNCTION, simple_url, uri.host)
    Log.log.debug{"PAC: result: #{@cache[simple_url]}"}
  end
  return @cache[simple_url]
end

#get_proxies(service_url) ⇒ Object

used to replace URI::Generic.find_proxy

Returns:

  • Array of URI, possibly empty



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# File 'lib/aspera/proxy_auto_config.rb', line 96

def get_proxies(service_url)
  # prepare result
  uri_list = []
  # execute PAC script
  proxy_list_str = find_proxy_for_url(service_url)
  if !proxy_list_str.is_a?(String)
    Log.log.warn{"PAC: did not return a String, returned #{proxy_list_str.class}"}
    return uri_list
  end
  proxy_list_str.strip!
  proxy_list_str.gsub!(/\s+/, ' ')
  proxy_list_str.split(';').each do |item|
    # strip and split by space
    parts = item.strip.split
    case parts.shift
    when 'DIRECT'
      Aspera.assert(parts.empty?){'DIRECT has no param'}
      Log.log.debug('ignoring proxy DIRECT')
    when 'PROXY'
      addr_port = parts.shift
      Aspera.assert_type(addr_port, String)
      Aspera.assert(parts.empty?){'PROXY shall have one param'}
      begin
        # PAC proxy addresses are <host>:<port>
        if /:[0-9]+$/.match?(addr_port)
          uri = URI.parse("proxy://#{addr_port}")
          # ruby v>2.6 allows
          uri.user = @proxy_user
          uri.password = @proxy_pass
          uri_list.push(uri)
        else
          Log.log.warn{"PAC: PROXY must be <address>:<port>, ignoring #{addr_port}"}
        end
      rescue StandardError => e
        Log.log.warn{"PAC: cannot parse #{addr_port} #{e}"}
      end
    else Log.log.warn{"PAC: ignoring proxy type #{parts.first}: not supported"}
    end
  end
  Log.log.debug{"Proxies: #{uri_list}"}
  return uri_list
end

#register_uri_generic ⇒ Object 



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# File 'lib/aspera/proxy_auto_config.rb', line 68

def register_uri_generic
  URI::Generic.register_proxy_finder{|url_str|get_proxies(url_str).first}
  # allow chaining
  return self
end