gridcentric_python_novaclient_ext 1.2.1533

GridCentric extension for OS novaclient.

Overview
========

An extension hook for novaclient that enables it to interact with the Gridcentric endpoints.

Command line usage
==================

After installing the operations provided by the Gridcentric extension will be available to the
nova command line application:

# Display all of the available commands of the nova script. The gridcentric bless, launch,
# list-blessed, list-launched, discard and gc-migrate are listed.
$ nova help

# Doing nova help <command> on any of these commands will display how to use them in detail.
$ nova help bless
usage: nova bless <instance id>

Bless an instance

Positional arguments:
<instance id> ID of the instance to bless

$ nova help launch
usage: nova launch [--target <target memory>] [--params <key=value>]
<blessed id>

Launch a new instance

Positional arguments:
<blessed id> ID of the blessed instance

Optional arguments:
--target <target memory>
The memory target of the launched instance
--params <key=value> Guest parameters to send to vms-agent

$ nova help discard
usage: nova discard <blessed id>

Discard a blessed instance

Positional arguments:
<blessed id> ID of the blessed instance

$ nova help gc-migrate
usage: nova gc-migrate <instance id> <destination host>

Migrate an instance using Gridcentric VMS

Positional arguments:
<instance id> ID of the instance to migrate
<destination host> Host to migrate to

$ nova help list-launched
usage: nova list-launched <blessed id>

List instances launched from this blessed instance.

Positional arguments:
<blessed id> ID of the blessed instance

$ nova help list-blessed
usage: nova list-blessed <server id>

List instances blessed from this instance.

Positional arguments:
<server id> ID of the instance


Scripting usage
===============

The novaclient hooks can also be accessed directly using the python API.

user = "admin"
apikey = "admin"
project = "openstackDemo"
authurl = "http://localhost:5000/v2.0"

extensions = shell.OpenStackComputeShell()._discover_extensions("1.1")
novaclient = NovaClient(user, apikey, project, authurl, extensions=extensions,
endpoint_type=shell.DEFAULT_NOVA_ENDPOINT_TYPE,
service_type=shell.DEFAULT_NOVA_SERVICE_TYPE)

def wait_for_status(server, status):
while server.status != status:
time.sleep(30)
server = novaclient.gridcentric.get(server.id)
return server

def wait_until_gone(server):
try:
while True:
server = novaclient.gridcentric.get(server.id)
time.sleep(10)
except Exception, e:
# server is no longer there.
pass

# Boot a new server using flavor 1 and the image passed in as the first arguement.
image_id = sys.argv[1]
flavor_id = 1
server = novaclient.servers.create("Gridcentric instance",
image_id,
flavor_id)
server = wait_for_status(server, "ACTIVE")

# Bless the server. This will return an instance of the blessed_server. We need to
# wait until the server becomes active.
blessed_server = novaclient.gridcentric.bless(server)[0]
blessed_server = wait_for_status(blessed_server, "BLESSED")

# Launch a new server based off of the blessed one. Note that we can do this
# by either calling launch on the server itself, or passing the server into the
# gridcentric manager.
launched_server = blessed_server.launch()[0]
launched_server2 = novaclient.gridcentric.launch(blessed_server)[0]

# list the servers that were launched from the blessed ones.
for s in blessed_server.list_launched():
print "Server %s was launched from %s" %(s.id, blessed_server.id)

# Delete the launched servers.
launched_server2 = wait_for_status(launched_server2, "ACTIVE")
launched_server2.delete()
launched_server = wait_for_status(launched_server, "ACTIVE")
novaclient.servers.delete(launched_server)

# W need to ensure that the launched instances have been deleted before discarding
# the blessed instance.
wait_until_gone(launched_server2)
wait_until_gone(launched_server)

# Delete the original server. Note we can delete this server
# and keep the blessed one around.
server.delete()

# Discard the blessed server
blessed_server.discard()