2ed2254879
Calling get_stack to poll for stack state transitions causes unnecessary high load on heat servers so should be avoided if possible (this is true whether get_stack lists all stacks or a fetches a single full stack). Heatclient has a utility function which instead polls for stack events (with a fallback to fetching the stack when events are not forthcoming). This function is used extensively by heat client and the openstackclient stack commands - it would be appropriate to use it here too. The timeout is passed to the stack create call, meaning that the stack will go to CREATE_FAILED if the timeout is exceeded. The default timeout_mins is usually 60 minutes, so the client-side timeout would never be reached anyway. Also, the current polling approach was not filtering for CREATE_COMPLETE so it wasn't actually waiting for anything. This change adds functional tests which cover get_stack, create_stack and list_stacks. test_stack_nested exercises the stack_create environment_files file composition. Change-Id: Ia14d47f0f51e1f8825b6de6d8dc5a12335913f55
Introduction
shade is a simple client library for operating OpenStack clouds. The key word here is simple. Clouds can do many many 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, you should probably use the lower level client libraries - or even the REST API directly. However, if what you want is to be able to write an application that talks to clouds no matter what crazy choices the deployer has made in an attempt to be more hipster than their self-entitled narcissist peers, then shade is for you.
shade started its life as some code inside of ansible. ansible has a bunch of different OpenStack related modules, and there was a ton of duplicated code. Eventually, between refactoring that duplication into an internal library, and adding logic and features that the OpenStack Infra team had developed to run client applications at scale, it turned out that we'd written nine-tenths of what we'd need to have a standalone library.
Example
Sometimes an example is nice. :
import shade
# Initialize and turn on debug logging
shade.simple_logging(debug=True)
# Initialize cloud
# Cloud configs are read with os-client-config
cloud = shade.openstack_cloud(cloud='mordred')
# Upload an image to the cloud
image = cloud.create_image(
'ubuntu-trusty', filename='ubuntu-trusty.qcow2', wait=True)
# Find a flavor with at least 512M of RAM
flavor = cloud.get_flavor_by_ram(512)
# Boot a server, wait for it to boot, and then do whatever is needed
# to get a public ip for it.
cloud.create_server(
'my-server', image=image, flavor=flavor, wait=True, auto_ip=True)