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GridCentric extension for OS novaclient.

Project description


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,

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

def wait_until_gone(server):
while True:
server = novaclient.gridcentric.get(
except Exception, e:
# server is no longer there.

# 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",
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" %(,

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

# W need to ensure that the launched instances have been deleted before discarding
# the blessed instance.

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

# Discard the blessed server

Project details

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