Compute¶

Set environment variables¶

To set up environmental variables and authenticate against Compute API endpoints, see Authenticate.

Get OpenStack credentials (API v2)¶

This example uses the get_nova_credentials_v2 method:

def get_nova_credentials_v2():
    d = {}
    d['version'] = '2'
    d['username'] = os.environ['OS_USERNAME']
    d['api_key'] = os.environ['OS_PASSWORD']
    d['auth_url'] = os.environ['OS_AUTH_URL']
    d['project_id'] = os.environ['OS_TENANT_NAME']
    return d

This code resides in the credentials.py file, which all samples import.

Use the get_nova_credentials_v2() method to populate and get a dictionary:

credentials = get_nova_credentials_v2()

List servers (API v2)¶

The following program lists servers by using the Compute API v2.

1. Import the following modules:

   from credentials import get_nova_credentials_v2
   from novaclient.client import Client
   

2. Get Nova credentials. See Get OpenStack credentials (API v2).

3. Instantiate the nova_client client object by using the credentials dictionary object:

   nova_client = Client(**credentials)
   

4. List servers by calling servers.list on nova_client object:

   print(nova_client.servers.list())
   

#!/usr/bin/env python
from credentials import get_nova_credentials_v2
from novaclient.client import Client

credentials = get_nova_credentials_v2()
nova_client = Client(**credentials)

print(nova_client.servers.list())

Create server (API v2)¶

The following program creates a server (VM) by using the Compute API v2.

1. Import the following modules:

   import time
   from credentials import get_nova_credentials_v2
   from novaclient.client import Client
   

2. Get OpenStack credentials. See Get OpenStack credentials (API v2).

3. Instantiate the nova_client client object by using the credentials dictionary object:

   nova_client = Client(**credentials)
   

4. Get the flavor and image to use to create a server. This code uses the cirros image, the m1.tiny flavor, and the private network:

   image = nova_client.images.find(name="cirros")
   flavor = nova_client.flavors.find(name="m1.tiny")
   net = nova_client.networks.find(label="private")
   

5. To create the server, use the network, image, and flavor:

   nics = [{'net-id': net.id}]
   instance = nova_client.servers.create(name="vm2", image=image,
   flavor=flavor, key_name="keypair-1", nics=nics)
   

6. Run the “Sleep for five seconds” command, and determine whether the server/vm was created by calling nova_client.servers.list():

   print("Sleeping for 5s after create command")
   time.sleep(5)
   print("List of VMs")
   print(nova_client.servers.list())
   

#!/usr/bin/env python
import time
from credentials import get_nova_credentials_v2
from novaclient.client import Client

try:
    credentials = get_nova_credentials_v2()
    nova_client = Client(**credentials)

    image = nova_client.images.find(name="cirros")
    flavor = nova_client.flavors.find(name="m1.tiny")
    net = nova_client.networks.find(label="private")
    nics = [{'net-id': net.id}]
    instance = nova_client.servers.create(name="vm2", image=image,
                                      flavor=flavor, key_name="keypair-1", nics=nics)
    print("Sleeping for 5s after create command")
    time.sleep(5)
    print("List of VMs")
    print(nova_client.servers.list())
finally:
    print("Execution Completed")

Delete server (API v2)¶

The following program deletes a server (VM) by using the Compute API v2.

1. Import the following modules:

   import time
   from credentials import get_nova_credentials_v2
   from novaclient.client import Client
   

2. Get Nova credentials. See Get OpenStack credentials (API v2).

3. Instantiate the nova_client client object by using the credentials dictionary object:

   nova_client = Client(**credentials)
   

4. Determine whether the vm1 server exists:

   1. List servers: servers_list.
   2. Iterate over servers_list and compare name with vm1.
   3. If true, set the variable name server_exists to True and break from the for loop:

   servers_list = nova_client.servers.list()
   server_del = "vm1"
   server_exists = False
   
   for s in servers_list:
       if s.name == server_del:
           print("This server %s exists" % server_del)
           server_exists = True
           break
   

5. If the server exists, run the delete method of the nova_client.servers object:

   nova_client.servers.delete(s)
   

#!/usr/bin/env python
from credentials import get_nova_credentials_v2
from novaclient.client import Client

credentials = get_nova_credentials_v2()
nova_client = Client(**credentials)

servers_list = nova_client.servers.list()
server_del = "vm1"
server_exists = False

for s in servers_list:
    if s.name == server_del:
        print("This server %s exists" % server_del)
        server_exists = True
        break
if not server_exists:
    print("server %s does not exist" % server_del)
else:
    print("deleting server..........")
    nova_client.servers.delete(s)
    print("server %s deleted" % server_del)

Update server (API v2)¶

The following program updates the name of a server (VM) by using the Compute API v2.

1. Import the following modules:

   from credentials import get_nova_credentials_v2
   from novaclient.client import Client
   from utils import print_server
   

   print_server is a method defined in utils.py and prints the server details as shown in the code listing below:

   def print_server(server):
       print("-"*35)
       print("server id: %s" % server.id)
       print("server name: %s" % server.name)
       print("server image: %s" % server.image)
       print("server flavor: %s" % server.flavor)
       print("server key name: %s" % server.key_name)
       print("user_id: %s" % server.user_id)
       print("-"*35)
   

2. Get OpenStack Credentials. See Get OpenStack credentials (API v2).

3. Instantiate the nova_client client object by using the credentials dictionary object:

   nova_client = Client(**credentials)
   

4. Get the server instance using server_id and print the details by calling print_server method:

   server_id = '99889c8d-113f-4a7e-970c-77f1916bfe14'
   server = nova_client.servers.get(server_id)
   n = server.name
   print_server(server)
   

5. Call server.update on the server object with the new value for name variable:

   server.update(name = n + '1')
   

6. Get the updated instance of the server:

   server_updated = nova_client.servers.get(server_id)
   

7. Call print_server again to check the update server details:

   print_server(server_updated)
   

#!/usr/bin/env python

from credentials import get_nova_credentials_v2
from novaclient.client import Client
from utils import print_server

credentials = get_nova_credentials_v2()
nova_client = Client(**credentials)

# Change the server_id specific to your environment

server_id = '99889c8d-113f-4a7e-970c-77f1916bfe14'
server = nova_client.servers.get(server_id)
n = server.name
print_server(server)

server.update(name=n +'1')
server_updated = nova_client.servers.get(server_id)
print_server(server_updated)

List flavors (API v2)¶

The following program lists flavors and their details by using the Compute API v2.

1. Import the following modules:

   from credentials import get_nova_credentials_v2
   from novaclient.client import Client
   from utils import print_flavors
   

   The print_flavors method is defined in utils.py and prints the flavor details:

   def print_flavors(flavor_list):
       for flavor in flavor_list:
          print("-"*35)
          print("flavor id : %s" % flavor.id)
          print("flavor name : %s" % flavor.name)
          print("-"*35)
   

2. Get OpenStack credentials. Get OpenStack credentials (API v2).

3. Instantiate the nova_client client object by using the credentials dictionary object:

   nova_client = Client(**credentials)
   

4. List flavors by calling list() on nova_client.flavors object:

   flavors_list =  nova_client.flavors.list()
   

5. Print the flavor details, id and name by calling print_flavors:

   print_flavors(flavors_list)
   

#!/usr/bin/env python

from credentials import get_nova_credentials_v2
from novaclient.client import Client
from utils import print_flavors

credentials = get_nova_credentials_v2()
nova_client = Client(**credentials)

flavors_list = nova_client.flavors.list()
print_flavors(flavors_list)

List floating IPs (API v2)¶

The following program lists the floating IPs and their details by using the Compute API v2.

1. Import the following modules:

   from credentials import get_nova_credentials_v2
   from novaclient.client import Client
   from utils import print_values_ip
   

   The print_values_ip method is defined in utils.py and prints the floating_ip object details:

   def print_values_ip(ip_list):
       ip_dict_lisl = []
       for ip in ip_list:
           print("-"*35)
           print("fixed_ip : %s" % ip.fixed_ip)
           print("id : %s" % ip.id)
           print("instance_id : %s" % ip.instance_id)
           print("ip : %s" % ip.ip)
           print("pool : %s" % ip.pool)
   

2. Get OpenStack credentials. See Get OpenStack credentials (API v2).

3. Instantiate the nova_client client object by using the credentials dictionary object:

   nova_client = Client(**credentials)
   

4. List floating IPs by calling list() on nova_client.floating_ips object:

   ip_list = nova_client.floating_ips.list()
   

5. Print the floating IP object details by calling print_values_ip:

   print_values_ip(ip_list)
   

#!/usr/bin/env python

from credentials import get_nova_credentials_v2
from novaclient.client import Client
from utils import print_values_ip

credentials = get_nova_credentials_v2()
nova_client = Client(**credentials)
ip_list = nova_client.floating_ips.list()
print_values_ip(ip_list)

List hosts (API v2)¶

The following program lists the hosts by using the Compute API v2.

1. Import the following modules:

   from credentials import get_nova_credentials_v2
   from novaclient.client import Client
   from utils import print_hosts
   

   The print_hosts method is defined in utils.py and prints the host object details:

   def print_hosts(host_list):
       for host in host_list:
          print("-"*35)
          print("host_name : %s" % host.host_name)
          print("service : %s" % host.service)
          print("zone : %s" % host.zone)
          print("-"*35)
   

2. Get OpenStack credentials. See Get OpenStack credentials (API v2).

3. Instantiate the nova_client client object by using the credentials dictionary object:

   nova_client = Client(**credentials)
   

4. List hosts by calling list() on nova_client.hosts object:

   host_list = nova_client.hosts.list()
   

5. Print the host object details by calling print_hosts(host_list):

   print_hosts(host_list)
   

#!/usr/bin/env python

from credentials import get_nova_credentials_v2
from novaclient.client import Client
from utils import print_hosts

credentials = get_nova_credentials_v2()
nova_client = Client(**credentials)
host_list = nova_client.hosts.list()

print_hosts(host_list)