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openstacksdk

openstacksdk is a client library for building applications to work with OpenStack clouds. The project aims to provide a consistent and complete set of interactions with OpenStack's many services, along with complete documentation, examples, and tools.

It also contains an abstraction interface layer. Clouds can do many things, but there are probably only about 10 of them that most people care about with any regularity. If you want to do complicated things, the per-service oriented portions of the SDK are for you. However, if what you want is to be able to write an application that talks to any OpenStack cloud regardless of configuration, then the Cloud Abstraction layer is for you.

More information about the history of openstacksdk can be found at https://docs.openstack.org/openstacksdk/latest/contributor/history.html

Getting started

openstacksdk aims to talk to any OpenStack cloud. To do this, it requires a configuration file. openstacksdk favours clouds.yaml files, but can also use environment variables. The clouds.yaml file should be provided by your cloud provider or deployment tooling. An example:

clouds:
  mordred:
    region_name: Dallas
    auth:
      username: 'mordred'
      password: XXXXXXX
      project_name: 'demo'
      auth_url: 'https://identity.example.com'

openstacksdk will look for clouds.yaml files in the following locations:

  • . (the current directory)
  • $HOME/.config/openstack
  • /etc/openstack

openstacksdk consists of three layers. Most users will make use of the proxy layer. Using the above clouds.yaml, consider listing servers:

import openstack

# Initialize and turn on debug logging
openstack.enable_logging(debug=True)

# Initialize connection
conn = openstack.connect(cloud='mordred')

# List the servers
for server in conn.compute.servers():
    print(server.to_dict())

openstacksdk also contains a higher-level cloud layer based on logical operations:

import openstack

# Initialize and turn on debug logging
openstack.enable_logging(debug=True)

# Initialize connection
conn = openstack.connect(cloud='mordred')

# List the servers
for server in conn.list_servers():
    print(server.to_dict())

The benefit of this layer is mostly seen in more complicated operations that take multiple steps and where the steps vary across providers. For example:

import openstack

# Initialize and turn on debug logging
openstack.enable_logging(debug=True)

# Initialize connection
conn = openstack.connect(cloud='mordred')

# Upload an image to the cloud
image = conn.create_image(
    'ubuntu-trusty', filename='ubuntu-trusty.qcow2', wait=True)

# Find a flavor with at least 512M of RAM
flavor = conn.get_flavor_by_ram(512)

# Boot a server, wait for it to boot, and then do whatever is needed
# to get a public IP address for it.
conn.create_server(
    'my-server', image=image, flavor=flavor, wait=True, auto_ip=True)

Finally, there is the low-level resource layer. This provides support for the basic CRUD operations supported by REST APIs and is the base building block for the other layers. You typically will not need to use this directly:

import openstack
import openstack.config.loader
import openstack.compute.v2.server

# Initialize and turn on debug logging
openstack.enable_logging(debug=True)

# Initialize connection
conn = openstack.connect(cloud='mordred')

# List the servers
for server in openstack.compute.v2.server.Server.list(session=conn.compute):
    print(server.to_dict())

Configuration

openstacksdk uses the openstack.config module to parse configuration. openstack.config will find cloud configuration for as few as one cloud and as many as you want to put in a config file. It will read environment variables and config files, and it also contains some vendor specific default values so that you don't have to know extra info to use OpenStack

  • If you have a config file, you will get the clouds listed in it
  • If you have environment variables, you will get a cloud named envvars
  • If you have neither, you will get a cloud named defaults with base defaults

You can view the configuration identified by openstacksdk in your current environment by running openstack.config.loader. For example:

$ python -m openstack.config.loader

More information at https://docs.openstack.org/openstacksdk/latest/user/config/configuration.html

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