Enable usage of proxies defined in environment (http(s)_proxy).

As far as proxies usage is concerned, keystone-client API and swift-client API behave differently because the former uses python Request library while the latter uses raw httplib. As a result, Keystone authentication honors environment variables http_proxy, https_proxy and no_proxy while Swift doesn't.

This patch, which code is mainly borrowed from Python Requests, makes Swift
data connections and Swift authentication connections behaving homogeneously.

Change-Id: Ic8a0089c35c458d7ed96e572e22429014298fe4c

1 files changed, 50 insertions, 0 deletions

diff --git a/swiftclient/utils.py b/swiftclient/utils.py
index a038dcc..a74eada 100644
--- a/swiftclient/utils.py
+++ b/swiftclient/utils.py
@@ -14,6 +14,23 @@
 # limitations under the License.
 """Miscellaneous utility functions for use with Swift."""
 
+import sys
+import os
+
+_ver = sys.version_info
+
+#: Python 2.x?
+is_py2 = (_ver[0] == 2)
+
+#: Python 3.x?
+is_py3 = (_ver[0] == 3)
+
+if is_py2:
+    from urllib import getproxies, proxy_bypass
+elif is_py3:
+    from urllib.request import getproxies, proxy_bypass
+
+
 TRUE_VALUES = set(('true', '1', 'yes', 'on', 't', 'y'))
 
 
@@ -55,3 +72,36 @@ def prt_bytes(bytes, human_flag):
         bytes = '%12s' % bytes
 
     return(bytes)
+
+
+# get_environ_proxies function, borrowed from python Requests
+# (www.python-requests.org)
+def get_environ_proxies(netloc):
+    """Return a dict of environment proxies."""
+
+    get_proxy = lambda k: os.environ.get(k) or os.environ.get(k.upper())
+
+    # First check whether no_proxy is defined. If it is, check that the URL
+    # we're getting isn't in the no_proxy list.
+    no_proxy = get_proxy('no_proxy')
+
+    if no_proxy:
+        # We need to check whether we match here. We need to see if we match
+        # the end of the netloc, both with and without the port.
+        no_proxy = no_proxy.replace(' ', '').split(',')
+
+        for host in no_proxy:
+            if netloc.endswith(host) or netloc.split(':')[0].endswith(host):
+                # The URL does match something in no_proxy, so we don't want
+                # to apply the proxies on this URL.
+                return {}
+
+    # If the system proxy settings indicate that this URL should be bypassed,
+    # don't proxy.
+    if proxy_bypass(netloc):
+        return {}
+
+    # If we get here, we either didn't have no_proxy set or we're not going
+    # anywhere that no_proxy applies to, and the system settings don't require
+    # bypassing the proxy for the current URL.
+    return getproxies()