openstack-manuals/doc/user-guide/section_sdk_auth_nova.xml
Christian Berendt 6be4f5775f Unified the syntax of the XML root element (user-guide)
The XML root element of Docbook XML files should match the following
format:

<ELEMENT xmlns="http://docbook.org/ns/docbook"
  xmlns:xi="http://www.w3.org/2001/XInclude"
  xmlns:xlink="http://www.w3.org/1999/xlink"
  version="5.0"
  xml:id="THE_XML_ID_OF_THE_ELEMENT">

Change-Id: Ic59684221ba99632c71e3f9b5f97ec74f56793a4
2014-07-09 19:51:07 +02:00

74 lines
3.7 KiB
XML

<?xml version="1.0" encoding="UTF-8"?>
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xi="http://www.w3.org/2001/XInclude"
xmlns:xlink="http://www.w3.org/1999/xlink"
version="5.0"
xml:id="sdk_auth_nova">
<title>Authenticate against a Compute endpoint</title>
<para>To authenticate against a Compute endpoint, instantiate a
<link
xlink:href="http://docs.openstack.org/developer/python-novaclient/api/novaclient.v1_1.client.html#novaclient.v1_1.client.Client"
> novaclient.v_1_1.client.Client</link> object:</para>
<programlisting language="python">from os import environ as env
import novaclient.v1_1.client as nvclient
nova = nvclient.Client(auth_url=env['OS_AUTH_URL'],
username=env['OS_USERNAME'],
api_key=env['OS_PASSWORD'],
project_id=env['OS_TENANT_NAME'],
region_name=env['OS_REGION_NAME'])</programlisting>
<para>Alternatively, you can instantiate a
<classname>novaclient.client.Client</classname> object and pass
the version number:</para>
<programlisting language="python">from os import environ as env
import novaclient
nova = novaclient.client.Client("1.1", auth_url=env['OS_AUTH_URL'],
username=env['OS_USERNAME'],
api_key=env['OS_PASSWORD'],
project_id=env['OS_TENANT_NAME'],
region_name=env['OS_REGION_NAME'])</programlisting>
<para>If you authenticate against an endpoint that uses a custom
authentication back end, you must load the authentication plug-in and pass
it to the constructor.</para>
<para>The Rackspace public cloud is an OpenStack deployment that
uses a custom authentication back end. To authenticate against
this cloud, you must install the <link
xlink:href="https://pypi.python.org/pypi/rackspace-novaclient/">
rackspace-novaclient</link> library that contains the Rackspace
authentication plug-in, called <literal>rackspace</literal>. The
following Python code shows the additional modifications required
to instantiate a <classname>Client</classname> object that can
authenticate against the Rackspace custom authentication back
end.</para>
<programlisting language="python">import novaclient.auth_plugin
import novaclient.v1_1.client as nvclient
from os import environ as env
auth_system = 'rackspace'
auth_plugin = novaclient.auth_plugin.load_plugin('rackspace')
nova = nvclient.Client(auth_url=env['OS_AUTH_URL'],
username=env['OS_USERNAME'],
api_key=env['OS_PASSWORD'],
project_id=env['OS_TENANT_NAME'],
region_name=env['OS_REGION_NAME'],
auth_system='rackspace',
auth_plugin=auth_plugin)</programlisting>
<para>If you set the <literal>OS_AUTH_SYSTEM</literal> environment
variable, check for this variable in your Python script to
determine whether you need to load a custom authentication back
end:</para>
<programlisting language="python">import novaclient.auth_plugin
import novaclient.v1_1.client as nvclient
from os import environ as env
auth_system = env.get('OS_AUTH_SYSTEM', 'keystone')
if auth_system != "keystone":
auth_plugin = novaclient.auth_plugin.load_plugin(auth_system)
else:
auth_plugin = None
nova = nvclient.Client(auth_url=env['OS_AUTH_URL'],
username=env['OS_USERNAME'],
api_key=env['OS_PASSWORD'],
project_id=env['OS_TENANT_NAME'],
region_name=env['OS_REGION_NAME'],
auth_system=auth_system,
auth_plugin=auth_plugin)</programlisting>
</section>