add Proxy configuration directive

lib/collectd-librato.py

@@ -164,6 +164,10 @@ def librato_config(c):
                 msg = '%s: Invalid value for FlushIntervalSecs: %s' % \
                           (plugin_name, val)
                 raise Exception(msg)
+        elif child.key == 'Proxy':
+            proxy = urllib2.ProxyHandler({'https': val, 'http': val})
+            opener = urllib2.build_opener(proxy)
+            urllib2.install_opener(opener)
 
     if not config.has_key('api_token'):
         raise Exception('APIToken not defined')