'subscription_id contains the Azure subscription id in the form of GUID
key_file contains the Azure X509 certificate in .pem form'

def __init__(self, subscription_id=None, key_file=None, **kwargs):

    self.subscription_id = subscription_id
    self.key_file = key_file
    self.follow_redirects = kwargs.get('follow_redirects', True)
    super(AzureNodeDriver, self).__init__(self.subscription_id, self.key_file, secure=True, **kwargs)
