First create a client instance with your credentials:
>>> from novaclient.client import Client
>>> nova = Client(VERSION, USERNAME, PASSWORD, PROJECT_ID, AUTH_URL)
Here VERSION can be: 1.1, 2 and 3.
Alternatively, you can create a client instance using the keystoneclient session API:
>>> from keystoneclient.auth.identity import v2
>>> from keystoneclient import session
>>> from novaclient.client import Client
>>> auth = v2.Password(auth_url=AUTH_URL,
username=USERNAME,
password=PASSWORD,
tenant_name=PROJECT_ID)
>>> sess = session.Session(auth=auth)
>>> nova = client.Client(VERSION, session=sess)
For more information on this keystoneclient API, see Using Sessions.
Then call methods on its managers:
>>> nova.servers.list()
[<Server: buildslave-ubuntu-9.10>]
>>> nova.flavors.list()
[<Flavor: 256 server>,
<Flavor: 512 server>,
<Flavor: 1GB server>,
<Flavor: 2GB server>,
<Flavor: 4GB server>,
<Flavor: 8GB server>,
<Flavor: 15.5GB server>]
>>> fl = nova.flavors.find(ram=512)
>>> nova.servers.create("my-server", flavor=fl)
<Server: my-server>
For more information, see the reference: