netconn-api/v2.0/ch_neutron_general_info.xml
ZhiQiang Fan be2546cc56 Fix incorrect language specification
The api sample of networks-get-last-page-res.xml has been referenced
as json language, which will cause incorrectly display html tag
instead of literal value.

Change-Id: I4e0ee407cca7f563149529157f991c89f577f65b
Closes-Bug: #1285403
2014-02-28 01:37:22 +08:00

449 lines
22 KiB
XML

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE chapter[
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<!ENTITY APIv2 'Networking API v2.0'>
]>
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xmlns:xi="http://www.w3.org/2001/XInclude"
xmlns:svg="http://www.w3.org/2000/svg"
xmlns:m="http://www.w3.org/1998/Math/MathML"
xmlns:html="http://www.w3.org/1999/xhtml"
xmlns:xsdxt="http://docs.rackspacecloud.com/xsd-ext/v1.0"
xmlns:db="http://docbook.org/ns/docbook" version="5.0"
xml:id="General_API_Information-d1e436">
<?dbhtml stop-chunking?>
<title>General API Information</title>
<para>The &APIv2; is a ReSTful HTTP service that uses all aspects
of the HTTP protocol including methods, URIs, media types,
response codes, and so on. Providers can use existing features
of the protocol including caching, persistent connections, and
content compression. For example, providers who employ a
caching layer can respond with a <errorcode>203</errorcode>
code instead of a <errorcode>200</errorcode> code when a
request is served from the cache. Additionally, providers can
offer support for conditional &GET; requests by using ETags,
or they may send a redirect in response to a &GET; request.
Create clients so that these differences are accounted
for.</para>
<section xml:id="Authentication-d1e444">
<title>Authentication and Authorization</title>
<para>The &APIv2; uses the <link
xlink:href="https://openstack.keystone.org">Keystone
Identity Service</link> as the default authentication
service. When Keystone is enabled, users that submit
requests to the OpenStack Networking service must provide
an authentication token in <emphasis role="bold"
>X-Auth-Token</emphasis> request header. You obtain
the token by authenticating to the Keystone endpoint. For
more information about Keystone, see the <link
xlink:href="http://docs.openstack.org/api/openstack-identity-service/2.0/content/"
><citetitle>OpenStack Identity Service API v2.0
Reference</citetitle></link>.</para>
<para>When Keystone is enabled, the
<literal>tenant_id</literal> attribute is not required
in create requests because the tenant ID is derived from
the authentication token.</para>
<para>The default authorization settings allow only
administrative users to create resources on behalf of a
different tenant.</para>
<para>OpenStack Networking uses information received from
Keystone to authorize user requests. OpenStack Networking
handles the following types of authorization policies: <itemizedlist>
<listitem>
<para><emphasis role="bold">Operation-based
policies</emphasis> specify access
criteria for specific operations, possibly
with fine-grained control over specific
attributes.</para>
</listitem>
<listitem>
<para><emphasis role="bold">Resource-based
policies</emphasis> access a specific
resource. Permissions might or might not be
granted depending on the permissions
configured for the resource. Currently
available for only the network
resource.</para>
</listitem>
</itemizedlist></para>
<para>The actual authorization policies enforced in OpenStack
Networking might vary from deployment to
deployment.</para>
</section>
<?hard-pagebreak?>
<section xml:id="Request_Response_Types">
<title>Request/Response Types</title>
<para>The &APIv2; supports the JSON data serialization
format.</para>
<para>The format for both the request and the response can be
specified by using the <code>Content-Type</code> header,
the <code>Accept</code> header or adding the
<code>.json</code> extension to the request
URI.</para>
<example>
<title>JSON Request with Headers</title>
<literallayout class="monospaced">POST /v1.0/tenants/tenantX/networks HTTP/1.1
Host 127.0.0.1:9696
Content-Type application/json
Accept application/json
Content-Length 57</literallayout>
<programlisting language="json"><xi:include href="samples/networks-post-req.json" parse="text"/></programlisting>
</example>
<example>
<title>JSON Response with Headers</title>
<literallayout class="monospaced">HTTP/1.1 201 Created
Content-Type application/json
Content-Length 204</literallayout>
<programlisting language="json"><xi:include href="samples/networks-post-res.json" parse="text"/></programlisting>
</example>
</section>
<section xml:id="filtering">
<title>Filtering and Column Selection</title>
<para>The &APIv2; supports filtering based on all top level
attributes of a resource. Filters are applicable to all
list requests.</para>
<para>For example, the following request returns all networks
named <literal>foobar</literal>:</para>
<programlisting language="bash" role="gutter: false">GET /v2.0/networks?name=foobar</programlisting>
<para>When you specify multiple filters, the &APIv2; returns
only objects that meet all filtering criteria. The
operation applies an AND condition among the
filters.</para>
<note>
<para>OpenStack Networking does not offer an OR mechanism
for filters.</para>
</note>
<para>Alternatively, you can issue a distinct request for each
filter and build a response set from the received
responses on the client-side.</para>
<para>By default, OpenStack Networking returns all attributes
for any show or list call. The &APIv2; has a mechanism to
limit the set of attributes returned. For example, return
<literal>id</literal>.</para>
<para>You can use the <literal>fields</literal> query
parameter to control the attributes returned from the
&APIv2;.</para>
<para>For example, the following request returns only
<literal>id</literal> and <literal>name</literal> for
each network:</para>
<programlisting language="bash" role="gutter: false">GET /v2.0/networks.json?fields=id&amp;fields=name</programlisting>
</section>
<section xml:id="Async_behaviour">
<title>Synchronous versus Asynchronous Plug-in
Behavior</title>
<para>The &APIv2; presents a logical model of network
connectivity consisting of networks, ports, and subnets.
It is up to the OpenStack Networking plug-in to
communicate with the underlying infrastructure to ensure
packet forwarding is consistent with the logical model. A
plug-in might perform these operations
asynchronously.</para>
<para>When an API client modifies the logical model by issuing
an HTTP &POST;, &PUT;, or &DELETE; request, the API call
might return before the plug-in modifies underlying
virtual and physical switching devices. However, an API
client is guaranteed that all subsequent API calls
properly reflect the changed logical model.</para>
<para>For example, if a client issues an HTTP &PUT; request to
set the attachment for a port, there is no guarantee that
packets sent by the interface named in the attachment are
forwarded immediately when the HTTP call returns. However,
it is guaranteed that a subsequent HTTP &GET; request to
view the attachment on that port returns the new
attachment value.</para>
<para>You can use the <literal>status</literal> attribute with
the network and port resources to determine whether the
OpenStack Networking plug-in has successfully completed
the configuration of the resource.</para>
</section>
<section xml:id="bulk_create_operations">
<title>Bulk Create Operations</title>
<para>The &APIv2; enables you to create several objects of the
same type in the same API request. Bulk create operations
use exactly the same API syntax as single create
operations except that you specify a list of objects
rather than a single object in the request body.</para>
<para>Bulk operations are always performed atomically, meaning
that either all or none of the objects in the request body
are created. If a particular plug-in does not support
atomic operations, the &APIv2; emulates the atomic
behavior so that users can expect the same behavior
regardless of the particular plug-in running in the
background.</para>
<para>OpenStack Networking might be deployed without support
for bulk operations and when the client attempts a bulk
create operation, a <errorcode>400</errorcode>
<errortext>Bad Request</errortext> error is
returned.</para>
<!-- <para>For information about how to submit bulk requests to the
&APIv2; see <xref linkend="bulk_create_networks"/>, <xref
linkend="bulK_create_subnets"/>, and <xref
linkend="bulk_create_ports"/>.</para> -->
</section>
<section xml:id="pagination">
<title>Pagination</title>
<para>To reduce load on the service, list operations will
return a maximum number of items at a time. To navigate
the collection, the parameters limit, marker and
page_reverse can be set in the URI. For example:</para>
<programlisting language="bash">?limit=100&amp;marker=1234&amp;page_reverse=False</programlisting>
<para>The <parameter>marker</parameter> parameter is the ID of
the last item in the previous list. The
<parameter>limit</parameter> parameter sets the page
size. The <parameter>page_reverse</parameter> parameter
sets the page direction. These parameters are optional. If
the client requests a limit beyond the maximum limit
configured by the deployment, the server returns the
maximum limit number of items.</para>
<para>For convenience, list responses contain atom "next"
links and "previous" links. The last page in the list
requested with 'page_reverse=False' will not contain
"next" link, and the last page in the list requested with
'page_reverse=True' will not contain "previous" link. The
following examples illustrate two pages with three items.
The first page was retrieved through:</para>
<programlisting language="bash">&GET; http://127.0.0.1:9696/v2.0/networks.json?limit=2</programlisting>
<para>Pagination is an optional feature of OpenStack
Networking API, and it might be disabled. If pagination is
disabled, the pagination parameters will be ignored and
return all the items.</para>
<para>If a particular plug-in does not support pagination
operations, and pagination is enabled, the &APIv2; will
emulate the pagination behavior so that users can expect
the same behavior regardless of the particular plug-in
running in the background.</para>
<para>Unfortunately OpenStack Networking does not expose any
mechanism to tell user if pagination is supported by
particular plug-in or enabled.</para>
<example>
<title>Network Collection, First Page: JSON
Request</title>
<literallayout class="monospaced">GET /v2.0/networks.json?limit=2 HTTP/1.1
Host: 127.0.0.1:9696
Content-Type: application/json
Accept: application/json</literallayout>
</example>
<example>
<title>Network Collection, First Page: JSON
Response</title>
<programlisting language="json"><xi:include href="samples/networks-get-first-page-res.json" parse="text"/></programlisting>
</example>
<example>
<title>Network Collection, First Page: XML Request</title>
<literallayout class="monospaced">
GET /v2.0/networks.xml?limit=2 HTTP/1.1
Host: 127.0.0.1:9696
Content-Type: application/xml
Accept: application/xml
</literallayout>
</example>
<example>
<title>Network Collection, First Page: XML
Response</title>
<programlisting language="xml"><xi:include href="samples/networks-get-first-page-res.xml" parse="text"/></programlisting>
</example>
<para>The last page won't show the "next" links</para>
<example>
<title>Network Collection, Last Page: JSON Request</title>
<literallayout class="monospaced">
GET /v2.0/networks.json?limit=2&amp;marker=71c1e68c-171a-4aa2-aca5-50ea153a3718 HTTP/1.1
Host: 127.0.0.1:9696
Content-Type: application/json
Accept: application/json
</literallayout>
</example>
<example>
<title>Network Collection, Last Page: JSON
Response</title>
<programlisting language="json"><xi:include href="samples/networks-get-last-page-res.json" parse="text"/></programlisting>
</example>
<example>
<title>Network Collection, Last Page: XML Request</title>
<literallayout class="monospaced">
GET /v2.0/networks.xml?limit=2&amp;marker=71c1e68c-171a-4aa2-aca5-50ea153a3718 HTTP/1.1
Host: 127.0.0.1:9696
Content-Type: application/xml
Accept: application/xml
</literallayout>
</example>
<example>
<title>Network Collection, Last Page: XML Response</title>
<programlisting language="xml"><xi:include href="samples/networks-get-last-page-res.xml" parse="text"/></programlisting>
</example>
</section>
<section xml:id="Sorting">
<title>Sorting</title>
<para>The results of list operations can be ordered using the
'sort_key' and 'sort_dir' parameters. Currently sorting
doesn't work with extended attributes of resource. The
'sort_key' and 'sort_dir' can be repeated, and the number
of 'sort_key' and 'sort_dir' provided must be same. The
sort_dir parameter indicates in which direction to sort.
Acceptable values are 'asc' (ascending) and 'desc'
(descending).</para>
<para>Sorting is optional feature of OpenStack Networking API,
and it might be disabled. If sorting is disabled, the
sorting parameters will be ignored.</para>
<para>If a particular plug-in does not support sorting
operations, and sorting is enabled, the &APIv2; will
emulate the sorting behavior so that users can expect the
same behavior regardless of the particular plug-in running
in the background.</para>
<para>Unfortunately OpenStack Networking does provide a
mechanism to tell users if specific plug-ins support or
have enabled sorting.</para>
</section>
<section xml:id="extensions">
<title>Extensions</title>
<para>The &APIv2; is extensible.</para>
<para>The purpose of &APIv2; extensions is to:</para>
<itemizedlist>
<listitem>
<para>Introduce new features in the API without
requiring a version change.</para>
</listitem>
<listitem>
<para>Introduce vendor-specific niche
functionality.</para>
</listitem>
<listitem>
<para>Act as a proving ground for experimental
functionalities that might be included in a future
version of the API.</para>
</listitem>
</itemizedlist>
<para>To programmatically determine which extensions are
available, issue a &GET; request on the
<command>v2.0/extensions</command> URI.</para>
<para>To query extensions individually by unique alias, issue
a &GET; request on the
<command>/v2.0/extensions/<replaceable>alias_name</replaceable></command>
URI. Use this method to easily determine if an extension
is available. If the extension is not available, a
<errorcode>404</errorcode>
<errortext>Not Found</errortext> response is
returned.</para>
<para>You can extend existing core API resources with new
actions or extra attributes. Also, you can add new
resources as extensions. Extensions usually have tags that
prevent conflicts with other extensions that define
attributes or resources with the same names, and with core
resources and attributes. Because an extension might not
be supported by all plug-ins, the availability of an
extension varies with deployments and the specific plug-in
in use.</para>
<para>For more information regarding specific extensions, see
<xref linkend="API_extensions"/></para>
</section>
<?hard-pagebreak?>
<section xml:id="faults">
<title>Faults</title>
<para>The &APIv2; returns an error response if a failure
occurs while processing a request. OpenStack Networking
uses only standard HTTP error codes.
4<varname>xx</varname> errors indicate problems in the
particular request being sent from the client.</para>
<informaltable rules="all">
<col width="10%"/>
<col width="20%"/>
<col width="70%"/>
<thead>
<tr>
<th>Error</th>
<th colspan="2">Description</th>
</tr>
</thead>
<tbody>
<tr>
<td rowspan="6">400</td>
<td rowspan="6">Bad Request</td>
<td>Malformed request URI or body</td>
</tr>
<tr>
<td>Requested admin state invalid</td>
</tr>
<tr>
<td>Invalid values entered</td>
</tr>
<tr>
<td>Bulk operations disallowed</td>
</tr>
<tr>
<td>Validation failed</td>
</tr>
<tr>
<td>Method not allowed for request body (such as
trying to update attributes that can be
specified at create-time only)</td>
</tr>
<tr>
<td rowspan="2">404</td>
<td rowspan="2">Not Found</td>
<td>Non existent URI</td>
</tr>
<tr>
<td>Resource not found</td>
</tr>
<tr>
<td rowspan="3">409</td>
<td rowspan="3">Conflict</td>
<td>Port configured on network</td>
</tr>
<tr>
<td>IP allocated on subnet</td>
</tr>
<tr>
<td>Conflicting IP allocation pools for
subnet</td>
</tr>
<tr>
<td>500</td>
<td>Internal server error</td>
<td>Internal OpenStack Networking error</td>
</tr>
<tr>
<td>503</td>
<td>Service unavailable</td>
<td>Failure in Mac address generation</td>
</tr>
</tbody>
</informaltable>
<para>Users submitting requests to the &APIv2; might also
receive the following errors:</para>
<itemizedlist>
<listitem>
<para><errorcode>401</errorcode> Unauthorized - If
invalid credentials are provided.</para>
</listitem>
<listitem>
<para><errorcode>403</errorcode> Forbidden - If the
user cannot access a specific resource or perform
the requested operation.</para>
</listitem>
</itemizedlist>
</section>
</chapter>