Source code for sas.qtgui.Utilities.ConnectionProxy
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import urllib.request, urllib.error, urllib.parse
import sys
import json
import logging
import re
'''
HTTP Proxy parser and Connection
connect() function:
- auto detects proxy in windows, osx
- in ux systems, the http_proxy enviroment variable must be set
- if it fails, try to find the proxy.pac address.
- parses the file, and looks up for all possible proxies
'''
[docs]class ConnectionProxy(object):
[docs] def __init__(self, url, timeout):
self.url = url
self.timeout = timeout
[docs] def _get_addresses_of_proxy_pac(self):
"""
Return a list of possible auto proxy .pac files being used,
based on the system registry (win32) or system preferences (OSX).
@return: list of urls
"""
pac_files = []
if sys.platform == 'win32':
try:
import winreg as winreg # used from python 2.0-2.6
except:
import winreg # used from python 2.7 onwards
net = winreg.OpenKey(
winreg.HKEY_CURRENT_USER,
"Software\\Microsoft\\Windows\\CurrentVersion\\Internet Settings"
)
n_subs, n_vals, last_mod = winreg.QueryInfoKey(net)
subkeys = {}
for i in range(n_vals):
this_name, this_val, this_type = winreg.EnumValue(net, i)
subkeys[this_name] = this_val
if 'AutoConfigURL' in list(subkeys.keys()) and len(subkeys['AutoConfigURL']) > 0:
pac_files.append(subkeys['AutoConfigURL'])
elif sys.platform == 'darwin':
import plistlib
sys_prefs = plistlib.readPlist(
'/Library/Preferences/SystemConfiguration/preferences.plist')
networks = sys_prefs['NetworkServices']
# loop through each possible network (e.g. Ethernet, Airport...)
for network in list(networks.items()):
# the first part is a long identifier
net_key, network = network
if 'ProxyAutoConfigURLString' in list(network['Proxies'].keys()):
pac_files.append(
network['Proxies']['ProxyAutoConfigURLString'])
return list(set(pac_files)) # remove redundant ones
[docs] def _parse_proxy_pac(self, pac_urls_list):
'''
For every pac file url in pac_urls_list, it tryes to connect.
If the connection is successful parses the file in search for
http proxies.
@param pac_urls_list: List with urls for the pac files
@return: list with all found http proxies
'''
proxy_url_list = []
for this_pac_url in pac_urls_list:
logging.debug('Trying pac file (%s)...' % this_pac_url)
try:
response = urllib.request.urlopen(
this_pac_url, timeout=self.timeout)
logging.debug('Succeeded (%s)...' % this_pac_url)
except Exception:
logging.debug('Failled (%s)...' % this_pac_url)
continue
pacStr = response.read()
possProxies = re.findall(
r"PROXY\s([^\s;,:]+:[0-9]{1,5})[^0-9]", pacStr + '\n')
for thisPoss in possProxies:
prox_url = 'http://' + thisPoss
proxy_dic = {'http': prox_url}
proxy_url_list.append(proxy_dic)
return proxy_url_list
[docs] def _set_proxy(self,proxy_dic=None):
'''
Sets connection proxy.
if proxy_dic is None get's teh proxy from the system.
To disable autodetected proxy pass an empty dictionary: {}
@param proxy_dic: format: {'http': 'http://www.example.com:3128/'}
'''
if proxy_dic is None:
# The default is to read the list of proxies from the environment variables <protocol>_proxy.
# If no proxy environment variables are set, then in a Windows environment proxy settings are
# obtained from the registry's Internet Settings section, and in a Mac OS X environment proxy
# information is retrieved from the OS X System Configuration
# Framework.
proxy = urllib.request.ProxyHandler()
else:
# If proxies is given, it must be a dictionary mapping protocol names to
# URLs of proxies.
proxy = urllib.request.ProxyHandler(proxy_dic)
opener = urllib.request.build_opener(proxy)
urllib.request.install_opener(opener)
[docs] def connect(self):
'''
Performs the request and gets a response from self.url
@return: response object from urllib2.urlopen
'''
req = urllib.request.Request(self.url)
response = None
try:
logging.debug("Trying Direct connection to %s..."%self.url)
response = urllib.request.urlopen(req, timeout=self.timeout)
except Exception as e:
logging.debug("Failed!")
logging.debug(e)
try:
logging.debug("Trying to use system proxy if it exists...")
self._set_proxy()
response = urllib.request.urlopen(req, timeout=self.timeout)
except Exception as e:
logging.debug("Failed!")
logging.debug(e)
pac_urls = self._get_addresses_of_proxy_pac()
proxy_urls = self._parse_proxy_pac(pac_urls)
for proxy in proxy_urls:
try:
logging.debug("Trying to use the proxy %s found in proxy.pac configuration"%proxy)
self._set_proxy(proxy)
response = urllib.request.urlopen(req, timeout=self.timeout)
except Exception as e:
logging.debug("Failed!")
logging.debug(e)
if response is not None:
logging.debug("The connection to %s was successful."%self.url)
else:
logging.warning("Connection to %s failed..."%self.url)
return response
if __name__ == "__main__":
from pprint import pprint
c = Connection()
response = c.connect()
if response is not None:
print(50 * '-')
content = json.loads(response.read().strip())
pprint(content)