Cannot authenticate on-demand

[Elijah]

I'm trying to set up a nova client and ensure that there are no authentication errors on client creation. My attempt is below:

from novaclient import client
from keystoneauth1 import session
from keystoneauth1.identity import v3

def setup_nova(creds):
    """
    Creates a nova instance with which we can leverage the OpenStack virtualization
    platform.

    :param creds: A dictionary containing the authorization url, username,
                  password, version, and project ID associated with the OpenStack
                  cluster.
    :type creds: dict
    """
    password = v3.PasswordMethod(username=creds['USERNAME'],
                                 password=creds['PASSWORD'],
                                 user_domain_name='default')

    auth = v3.Auth(auth_url=creds['AUTH_URL'],
                   auth_methods=[password],
                   project_id=creds['PROJECT_ID'])

    sess = session.Session(auth=auth)
    nova = client.Client(creds['VERSION'], session=sess)
    nova.authenticate()
    return nova

However, the `nova.authenticate()` call throws a novaclient.exceptions.InvalidUsage which tells me to authenticate the Session object. The Session object doesn't seem to have a way to authenticate on-demand, though.

Perhaps I'm missing something, but if there isn't a way to do this, there's either a bug in python-novaclient or in keystoneauth.

[Ali Jabbar (jabbar-ali)]

Hi ,
Could you please let share what is your end objective and why you want to do this ?

a) Are you trying to build a new feature ?

b) Or you want to do some kind of sanity check before launching any instance ?

Please share !!

[Elijah (erip)]

I think it's normal to enter credentials before attempting to make requests. I don't want to need to add a check for Unauthorized exceptions for every different type of request the user might want to make.

[Ali Jabbar (jabbar-ali)]

So are you saying that current way of handling is OK and there is no need of modification
 ?

[Elijah (erip)]

Clearly that's not what I'm saying--if it were, I wouldn't have filed this bug.

Imagine this user experience:

1. You go to ATM.
2. You enter bank card.
3. You type PIN.
4. You attempt to make a withdraw.
5. To your chagrin, you're alerted that your pin is wrong.

This is a terrible experience. Similarly, the way OpenStack (or atleast the python-novaclient module) works is quite analogous to this and should be changed (or at least extended).

[Launchpad Janitor (janitor)]

[Expired for python-novaclient because there has been no activity for 60 days.]