openstack-manuals/doc/user-guide/section_sdk_nova.xml

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  xml:id="sdk_compute_apis">
    <title>Compute</title>
    <?dbhtml stop-chunking?>
    <para>To use the information in this section, you must be familiar with OpenStack Compute.</para>
    <section xml:id="sdk_compute_env">
        <title>Set environment variables</title>
        <para>To set up environmental variables and authenticate
            against Compute API endpoints, see <xref
                linkend="sdk_auth"/>.</para>
    </section>
    <section xml:id="sdk_compute_get_openstack_credentials_v2">
        <title>Get OpenStack credentials (API v2)</title>
        <para>These example use the
                <code>get_nova_credentials_v2</code> method:</para>
        <programlisting language="python">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</programlisting>
        <para>This code resides in the
                <filename>credentials.py</filename> file, which all
            samples import.</para>
        <para>Use the <code>get_nova_credentials_v2()</code> method to
            populate and get a dictionary:</para>
        <programlisting language="python">credentials = get_nova_credentials_v2()</programlisting>
    </section>

    <section xml:id="sdk_compute_list_servers">
        <title>List servers (API v2)</title>
        <para>The following program lists servers by using the Compute
            API v2.</para>
        <procedure>
            <title>To list servers</title>
            <step>
                <para>Import the following modules:</para>
                <programlisting language="python">from credentials import get_nova_credentials_v2
from novaclient.client import Client</programlisting>
            </step>
            <step>
                <para>Get Nova credentials. See <xref
                        linkend="sdk_compute_get_openstack_credentials_v2"
                    />.</para>
            </step>
            <step>
                <para>Instantiate the <literal>nova_client</literal>
                    client object by using the
                        <literal>credentials</literal> dictionary
                    object:</para>
                <programlisting language="python">nova_client = Client(**credentials)</programlisting>
            </step>
            <step>
                <para>List servers by calling
                        <literal>servers.list</literal> on
                        <literal>nova_client</literal> object:</para>
                <programlisting language="python">print(nova_client.servers.list())</programlisting>
            </step>
        </procedure>
        <example>
            <title>List servers code listing</title>
            <programlisting language="python">#!/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())</programlisting>
        </example>
    </section>
    <section xml:id="sdk_compute_create_server_v2">
        <title>Create server (API v2)</title>
        <para>The following program creates a server (VM) by using the
            Compute API v2.</para>
        <procedure>
            <title>To create a server</title>
            <step>
                <para>Import the following modules:</para>
                <programlisting language="python">import time
from credentials import get_nova_credentials_v2
from novaclient.client import Client</programlisting>
            </step>
            <step>
                <para>Get OpenStack credentials. See <xref
                        linkend="sdk_compute_get_openstack_credentials_v2"
                    />.</para>
            </step>
            <step>
                <para>Instantiate the <literal>nova_client</literal>
                    client object by using the
                        <literal>credentials</literal> dictionary
                    object:</para>
                <programlisting language="python">nova_client = Client(**credentials)</programlisting>
            </step>
            <step>
                <para>Get the flavor and image to use to create a
                    server. This code uses the
                        <literal>cirros</literal> image, the
                        <literal>m1.tiny</literal> flavor, and the
                        <literal>private</literal> network:</para>
                <programlisting language="python">image = nova_client.images.find(name="cirros")
flavor = nova_client.flavors.find(name="m1.tiny")
net = nova_client.networks.find(label="private")</programlisting>
            </step>
            <step>
                <para>To create the server, use the network, image, and
                    flavor:</para>
                <programlisting language="python">nics = [{'net-id': net.id}]
instance = nova_client.servers.create(name="vm2", image=image,
                                      flavor=flavor, key_name="keypair-1", nics=nics)</programlisting>
            </step>
            <step>
                <para>Sleep for five seconds and determine whether the
                    server/vm was created by calling
                        <literal>nova_client.servers.list()</literal>:</para>
                <programlisting language="python">print("Sleeping for 5s after create command")
time.sleep(5)
print("List of VMs")
print(nova_client.servers.list())</programlisting>
            </step>
        </procedure>
        <example>
            <title>Create server code listing</title>
            <programlisting language="python">#!/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")</programlisting>
        </example>
    </section>
    <section xml:id="sdk_compute_delete_server_v2">
        <title>Delete server (API v2)</title>
        <para>The following program deletes a server (VM) by using the
            Compute API v2.</para>
        <procedure>
            <title>To delete a server</title>
            <step>
                <para>Import the following modules:</para>
                <programlisting language="python">import time
from credentials import get_nova_credentials_v2
from novaclient.client import Client</programlisting>
            </step>
            <step>
                <para>Get Nova credentials. See <xref
                        linkend="sdk_compute_get_openstack_credentials_v2"
                    />.</para>
            </step>
            <step>
                <para>Instantiate the <literal>nova_client</literal>
                    client object by using the
                        <literal>credentials</literal> dictionary
                    object:</para>
                <programlisting language="python">nova_client = Client(**credentials)</programlisting>
            </step>
            <step>
                <para>Determine whether the <literal>vm1</literal>
                    server exists:</para>
                <substeps>
                    <step>
                        <para>List servers:
                                <literal>servers_list</literal>.</para>
                    </step>
                    <step>
                        <para>Iterate over
                                <literal>servers_list</literal> and
                            compare name with
                            <literal>vm1</literal>.</para>
                    </step>
                    <step>
                        <para>If true, set the variable name
                                <literal>server_exists</literal> to
                                <literal>True</literal> and break from
                                the for loop:</para>
                         <programlisting language="python">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</programlisting>
                    </step>
                </substeps>
            </step>
            <step>
                <para>If the server exists, run the
                        <literal>delete</literal> method of the
                        <literal>nova_client.servers</literal>
                    object:</para>
                <programlisting language="python">nova_client.servers.delete(s)</programlisting>
            </step>

        </procedure>
        <example>
            <title>Delete server code listing</title>
            <programlisting language="python">#!/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)</programlisting>
        </example>
    </section>
    <section xml:id="sdk_update_server_v2">
        <title>Update server (API v2)</title>
        <para>The following program updates the name of a server (VM)
            by using the Compute API v2.</para>
        <procedure>
            <title>To update a server</title>
            <step>
                <para>Import the following modules:</para>
                <programlisting language="python">from credentials import get_nova_credentials_v2
from novaclient.client import Client
from utils import print_server</programlisting>
                <para><literal>print_server</literal> is a method
                    defined in <filename>utils.py</filename> and
                    prints the server details as shown in the code
                    listing below:</para>
                <programlisting language="python">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)</programlisting>
            </step>
            <step>
                <para>Get OpenStack Credentials. See <xref
                        linkend="sdk_compute_get_openstack_credentials_v2"
                    />.</para>
            </step>
            <step>
                <para>Instantiate the <literal>nova_client</literal>
                    client object by using the
                        <literal>credentials</literal> dictionary
                    object:</para>
                <programlisting language="python">nova_client = Client(**credentials)</programlisting>
            </step>
            <step>
                <para>Get the server instance using
                        <literal>server_id</literal> and print the
                    details by calling <literal>print_server</literal>
                    method:</para>
                <programlisting language="python">server_id = '99889c8d-113f-4a7e-970c-77f1916bfe14'
server = nova_client.servers.get(server_id)
n = server.name
print_server(server)</programlisting>
            </step>
            <step>
                <para>Call <code>server.update</code> on the server
                    object with the new value for
                        <literal>name</literal> variable:</para>
                <programlisting language="python">server.update(name = n + '1')</programlisting>
            </step>
            <step>
                <para>Get the updated instance of the server:</para>
                <programlisting language="python">server_updated = nova_client.servers.get(server_id)</programlisting>
            </step>
            <step>
                <para>Call <literal>print_server</literal> again to
                    check the update server details:</para>
                <programlisting language="python">print_server(server_updated)</programlisting>
            </step>

        </procedure>
        <example>
            <title>Update server code listing</title>
            <programlisting language="python">#!/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)</programlisting>
        </example>
    </section>
    <section xml:id="list_flavors_v2">
        <title>List flavors (API v2)</title>
        <para>The following program lists flavors and their details by
            using the Compute API v2.</para>
        <procedure>
            <title>To list flavors</title>
            <step>
                <para>Import the following modules:</para>
                <programlisting language="python">from credentials import get_nova_credentials_v2
from novaclient.client import Client
from utils import print_flavors</programlisting>
                <para>The <literal>print_flavors</literal> method is
                    defined in <filename>utils.py</filename> and
                    prints the flavor details:</para>
                <programlisting language="python">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)</programlisting>
            </step>
            <step>
                <para>Get OpenStack credentials. See <xref
                        linkend="sdk_compute_get_openstack_credentials_v2"
                    />.</para>
            </step>
            <step>
                <para>Instantiate the <literal>nova_client</literal>
                    client object by using the
                        <literal>credentials</literal> dictionary
                    object:</para>
                <programlisting language="python">nova_client = Client(**credentials)</programlisting>
            </step>
            <step>
                <para>List flavors by calling
                        <literal>list()</literal> on
                        <literal>nova_client.flavors</literal>
                    object:</para>
                <programlisting language="python">flavors_list =  nova_client.flavors.list()</programlisting>
            </step>
            <step>
                <para>Print the flavor details, id and name by calling
                        <literal>print_flavors</literal>:</para>
                <programlisting language="python">print_flavors(flavors_list)</programlisting>
            </step>
        </procedure>
        <example>
            <title>List flavors code listing</title>
            <programlisting language="python">#!/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)</programlisting>
        </example>
    </section>
    <section xml:id="list_floating_ips_python_client">
        <title>List floating IPs (API v2)</title>
        <para>The following program lists the floating IPs and their
            details by using the Compute API v2.</para>
        <procedure>
            <title>To list floating IPs</title>
            <step>
                <para>Import the following modules:</para>
                <programlisting language="python">from credentials import get_nova_credentials_v2
from novaclient.client import Client
from utils import print_values_ip</programlisting>
                <para>The <literal>print_values_ip</literal> method is
                    defined in <filename>utils.py</filename> and
                    prints the floating_ip object details:</para>
                <programlisting language="python">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)</programlisting>
            </step>
            <step>
                <para>Get OpenStack credentials. See <xref
                        linkend="sdk_compute_get_openstack_credentials_v2"
                    />.</para>
            </step>
            <step>
                <para>Instantiate the <literal>nova_client</literal>
                    client object by using the
                        <literal>credentials</literal> dictionary
                    object:</para>
                <programlisting language="python">nova_client = Client(**credentials)</programlisting>
            </step>
            <step>
                <para>List floating IPs by calling
                        <literal>list()</literal> on
                        <literal>nova_client.floating_ips</literal>
                    object:</para>
                <programlisting language="python">ip_list = nova_client.floating_ips.list()</programlisting>
            </step>
            <step>
                <para>Print the floating IP object details by calling
                        <literal>print_values_ip</literal>:</para>
                <programlisting language="python">print_values_ip(ip_list)</programlisting>
            </step>
        </procedure>
        <example>
            <title>List floating IPs code listing</title>
            <programlisting language="python">#!/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)</programlisting>
        </example>
    </section>
    <section xml:id="list_hosts_v2">
        <title>List hosts (API v2)</title>
        <para>The following program lists the hosts by
            using the Compute API v2.</para>
        <procedure>
            <title>To list hosts</title>
            <step>
                <para>Import the following modules:</para>
                <programlisting language="python">from credentials import get_nova_credentials_v2
from novaclient.client import Client
from utils import print_hosts</programlisting>
                <para>The <literal>print_hosts</literal> method is
                    defined in <filename>utils.py</filename> and
                    prints the host object details:</para>
                <programlisting language="python">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)</programlisting>
            </step>
            <step>
                <para>Get OpenStack credentials. See <xref
                        linkend="sdk_compute_get_openstack_credentials_v2"
                    />.</para>
            </step>
            <step>
                <para>Instantiate the <literal>nova_client</literal>
                    client object by using the
                        <literal>credentials</literal> dictionary
                    object:</para>
                <programlisting language="python">nova_client = Client(**credentials)</programlisting>
            </step>
            <step>
                <para>List hosts by calling <literal>list()</literal>
                    on <literal>nova_client.hosts</literal>
                    object:</para>
                <programlisting language="python">host_list = nova_client.hosts.list()</programlisting>
            </step>
            <step>
                <para>Print the host object details by calling
                        <literal>print_hosts(host_list)</literal>:</para>
                <programlisting language="python">print_hosts(host_list)</programlisting>
            </step>
        </procedure>
        <example>
            <title>List hosts code listing</title>
            <programlisting language="python">#!/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)</programlisting>
        </example>
    </section>
</section>