Merge lp:~xnox/launchpadlib/proxy into lp:launchpadlib

[Dimitri John Ledkov]

i hate proxies.

[lp:~xnox/launchpadlib/proxy]

138. By Dimitri John Ledkov on 2014-11-08

Support proxy settings.

[Barry Warsaw (barry)]

Can you devise some tests for this change?

review: Needs Fixing

[Dimitri John Ledkov (xnox)]

So I went to look at writting tests for this. I wanted to do something simple - set environment, initialise Launchpad object and check the proxy that is used by underlying http technology.

This got me digging through all the objects involved all the way down to httplib2.Http class that is the ultimate consumer of the proxy_info variable.

At this point I have also discovered that we are overriding the proxy_info default to None - which in httplib2.Http speak has meaning "do not use proxy". The other option is to provide a static ProxyInfo definition (as done in this branch) which would make the proxy settings stick through the lifecycle on the initialised object.

The default for httplib2.Http however is to pass a callable as proxy_info which accepts method as a parameter and determines the proxy settings on the fly. The default implementation of such a callable is httplib2.Http.proxy_from_the_environment(method="http"). Thus I'm proposing to stop overriding proxy_info to value None (aka "No proxy") and instead switch the default value of proxy_info to httplib2.Http.proxy_from_the_environment, as that's what the default value of proxy_info is in the httplib2.Http class which we are subclassing across the stack.

review: Needs Resubmitting

Unmerged revisions

138. By Dimitri John Ledkov on 2014-11-08

Support proxy settings.

=== modified file 'src/launchpadlib/launchpad.py'
--- src/launchpadlib/launchpad.py	2014-07-03 10:44:33 +0000
+++ src/launchpadlib/launchpad.py	2014-11-08 12:04:34 +0000
@@ -24,10 +24,20 @@
 import os
 try:
     from urllib.parse import urlsplit
+    from urllib.parse import urlparse
 except:
     from urlparse import urlsplit
+    from urlparse import urlparse
 import warnings
 
+try:
+    import socks
+    import libproxy
+    from httplib2 import ProxyInfo
+    _proxy_support = True
+except ImportError:
+    _proxy_support = False
+
 from lazr.restfulclient.resource import (
     CollectionWithKeyBasedLookup,
     HostedFile,           # Re-import for client convenience
@@ -53,6 +63,34 @@
 OAUTH_REALM = 'https://api.launchpad.net'
 
 
+def _auto_detect_proxy(url):
+    if not _proxy_support:
+        return None
+
+    protocol_map = {
+        'http': socks.PROXY_TYPE_HTTP,
+        'socks': socks.PROXY_TYPE_SOCKS5,
+        'socks5': socks.PROXY_TYPE_SOCKS5,
+        'socks4': socks.PROXY_TYPE_SOCKS4,
+    }
+
+    pf = libproxy.ProxyFactory()
+    proxies = pf.getProxies(url)
+    for proxy in proxies:
+        proxy_components = urlparse(proxy)
+        protocol = protocol_map.get(proxy_components.scheme, None)
+        if protocol is None:
+            return None
+
+        return ProxyInfo(
+            protocol,
+            proxy_components.hostname,
+            proxy_components.port,
+            proxy_user=proxy_components.username,
+            proxy_pass=proxy_components.password,
+        )
+
+
 class PersonSet(CollectionWithKeyBasedLookup):
     """A custom subclass capable of person lookup by username."""
 
@@ -181,6 +219,8 @@
         :type service_root: string
         """
         service_root = uris.lookup_service_root(service_root)
+        if proxy_info is None:
+            proxy_info = _auto_detect_proxy(service_root)
         if (service_root.endswith(version)
             or service_root.endswith(version + '/')):
             error = ("It looks like you're using a service root that "
@@ -201,6 +241,8 @@
             credentials, service_root, cache, timeout, proxy_info, version)
 
     def httpFactory(self, credentials, cache, timeout, proxy_info):
+        if proxy_info is None:
+            proxy_info = _auto_detect_proxy(str(self._root_uri))
         return LaunchpadOAuthAwareHttp(
             self, self.authorization_engine, credentials, cache, timeout,
             proxy_info)
@@ -358,6 +400,9 @@
             credentials.consumer.application_name = (
                 authorization_engine.application_name)
 
+        if proxy_info is None:
+            proxy_info = _auto_detect_proxy(service_root)
+
         return cls(credentials, authorization_engine, credential_store,
                    service_root, cache, timeout, proxy_info, version)
 
@@ -369,6 +414,8 @@
         """Get access to Launchpad without providing any credentials."""
         (service_root, launchpadlib_dir, cache_path,
          service_root_dir) = cls._get_paths(service_root, launchpadlib_dir)
+        if proxy_info is None:
+            proxy_info = _auto_detect_proxy(service_root)
         token = AnonymousAccessToken()
         credentials = Credentials(consumer_name, access_token=token)
         return cls(credentials, None, None, service_root=service_root,
@@ -482,6 +529,9 @@
         (service_root, launchpadlib_dir, cache_path,
          service_root_dir) = cls._get_paths(service_root, launchpadlib_dir)
 
+        if proxy_info is None:
+            proxy_info = _auto_detect_proxy(service_root)
+
         if (application_name is None and consumer_name is None and
             authorization_engine is None):
             raise ValueError(