This document gives a quick introduction to using the Openstack Python client to discover and consume compute resources.

Before beginning, get an account as described in the Introduction . This is the right place to read about writing python scripts. A companion document shows how to use the Command Line .

From a suitable host (this was done on linux.cs.uchicago.edu), create your environment.

$ python3 -m venv cloudsdk
$ source cloudsdk/bin/activate
$ pip3 install openstacksdk
$ python -m openstack version

Obtain your configuration from the Web Interface . The preceding link is for authenticated and authorized users only. Please read Intro for access. After logging in to the web interface at https://overcloud.cs.uchicago.edu, click the menu on the left side, Project→API Access. On the right side of the top of the page, click "Download Openstack RC File"→"Openstack clouds.yaml file".

Save the clouds.yaml file to the current working directory, or see the Upstream Docs about config file search order:

USER_CONFIG_DIR
    Linux: ~/.config/openstack
    OSX: ~/Library/Application Support/openstack
    Windows: C:\Users\USERNAME\AppData\Local\OpenStack\openstack
SITE_CONFIG_DIR
    Linux: /etc/openstack
    OSX: /Library/Application Support/openstack
    Windows: C:\ProgramData\OpenStack\openstack

clouds:
  openstack:
    auth:
      auth_url: https://overcloud.cs.uchicago.edu:5000
      username: "CNetID"
      password: "sekret"
      project_id: YOUR PROJECT UUID
      project_name: "CNetID"
      user_domain_name: "CS_LDAP"
    region_name: "RegionOne"
    interface: "public"
    identity_api_version: 3

The main flaw here is that you are taking risks by storing your University credentials in a file. Instead, you can use the API or web interface to create an Application Credential. For example,

openstack application credential create --secret sekret --role member --expiration 2020-10-10:10:10:10 --restricted myapp

Ensure you can load the python module

python -m openstack version

Check your configuration

python -m openstack.config.loader

Check the exact error if one is displayed. For example, if you see

keystoneauth1.exceptions.auth_plugins.MissingRequiredOptions: Auth plugin requires parameters which were not given: auth_url

You have failed to provide a configuration file. This is different from a syntax error, but not so different from a permission problem, for example.

The following Python code shows how to create and destroy a server, and obtain information about Networks, Images, and Flavors. Consult the API Resource Documentation to see what else is possible.

For your learning, contrast this with the equivalent actions that are taken in the Command Line Usage Guide .

import openstack
from openstack.config import loader
# to enable debug logging
# openstack.enable_logging(True)
config = loader.OpenStackConfig()
cloud = openstack.connect(cloud='openstack')
flavor = cloud.get_flavor_by_ram(2048)
# print(flavor.name)
image = cloud.get_image('20.04')
# pretty print
# cloud.pprint(image)
network = cloud.get_network('campus37')
try:
    server = cloud.create_server('myserver', image=image, flavor=flavor, network=network, wait=True, auto_ip=True)
finally:
    cloud.delete_server('myserver', wait=True, delete_ips=True)