2011-01-19 16:38:39 -05:00
|
|
|
..
|
|
|
|
|
Copyright 2010 OpenStack, LLC
|
|
|
|
|
All Rights Reserved.
|
|
|
|
|
|
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License"); you may
|
|
|
|
|
not use this file except in compliance with the License. You may obtain
|
|
|
|
|
a copy of the License at
|
|
|
|
|
|
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
|
|
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
|
|
|
distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
|
|
|
WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
|
|
|
License for the specific language governing permissions and limitations
|
|
|
|
|
under the License.
|
|
|
|
|
|
|
|
|
|
Quick Guide to Getting Started with Glance
|
|
|
|
|
==========================================
|
|
|
|
|
|
|
|
|
|
Glance is a server that provides the following services:
|
|
|
|
|
|
|
|
|
|
* Ability to store and retrieve virtual machine images
|
2011-01-20 14:20:34 -05:00
|
|
|
* Ability to store and retrieve metadata about these virtual machine images
|
2011-01-19 16:38:39 -05:00
|
|
|
* FUTURE: Convert a virtual machine image from one format to another
|
|
|
|
|
* FUTURE: Help caching proxies such as Varnish or Squid cache machine images
|
|
|
|
|
|
|
|
|
|
Communication with Glance occurs via a REST-like HTTP interface.
|
|
|
|
|
|
2011-01-20 14:20:34 -05:00
|
|
|
However, Glance includes a :doc:`Client <client>` class that makes working with Glance
|
2011-01-19 16:38:39 -05:00
|
|
|
easy and straightforward.
|
|
|
|
|
|
|
|
|
|
In the Cactus release, there will be also command-line tools for
|
|
|
|
|
interacting with Glance.
|
|
|
|
|
|
|
|
|
|
Overview of Glance Architecture
|
|
|
|
|
-------------------------------
|
|
|
|
|
|
|
|
|
|
There are two main parts to Glance's architecture:
|
|
|
|
|
|
|
|
|
|
* Glance API server
|
|
|
|
|
* Glance Registry server(s)
|
|
|
|
|
|
|
|
|
|
Glance API Server
|
|
|
|
|
*****************
|
|
|
|
|
|
|
|
|
|
The API server is the main interface for Glance. It routes requests from
|
|
|
|
|
clients to registries of image metadata and to its **backend stores**, which
|
|
|
|
|
are the mechanisms by which Glance actually saves incoming virtual machine
|
|
|
|
|
images.
|
|
|
|
|
|
|
|
|
|
The backend stores that Glance can work with are as follows:
|
|
|
|
|
|
|
|
|
|
* **Swift**
|
|
|
|
|
|
|
|
|
|
Swift is the highly-available object storage project in OpenStack. More
|
|
|
|
|
information can be found about Swift `here <http://swift.openstack.org>`_.
|
|
|
|
|
|
|
|
|
|
* **Filesystem**
|
|
|
|
|
|
|
|
|
|
The default backend that Glance uses to store virtual machine images
|
|
|
|
|
is the filesystem backend. This simple backend writes image files to the
|
|
|
|
|
local filesystem.
|
|
|
|
|
|
|
|
|
|
* **S3**
|
|
|
|
|
|
|
|
|
|
This backend allows Glance to store virtual machine images in Amazon's
|
|
|
|
|
S3 service.
|
|
|
|
|
|
|
|
|
|
* **HTTP**
|
|
|
|
|
|
|
|
|
|
Glance can read virtual machine images that are available via
|
|
|
|
|
HTTP somewhere on the Internet. This store is **readonly**
|
|
|
|
|
|
|
|
|
|
Glance Registry Servers
|
|
|
|
|
***********************
|
|
|
|
|
|
|
|
|
|
Glance registry servers are servers that conform to the Glance Registry API.
|
|
|
|
|
Glance ships with a reference implementation of a registry server that
|
|
|
|
|
complies with this API (``bin/glance-registry``).
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Starting Up Glance's Servers
|
|
|
|
|
----------------------------
|
|
|
|
|
|
|
|
|
|
To get started using Glance, you must first start the Glance API server.
|
|
|
|
|
After installing Glance, starting up the Glance API server is easy. Simply
|
|
|
|
|
start the ``glance-api`` program, like so::
|
|
|
|
|
|
|
|
|
|
$> glance-api
|
|
|
|
|
|
|
|
|
|
Configuring the Glance API server
|
|
|
|
|
*********************************
|
|
|
|
|
|
|
|
|
|
There are a few options that can be supplied to the API server when
|
|
|
|
|
starting it up:
|
|
|
|
|
|
|
|
|
|
* ``verbose``
|
|
|
|
|
|
|
|
|
|
Show more verbose/debugging output
|
|
|
|
|
|
|
|
|
|
* ``api_host``
|
|
|
|
|
|
|
|
|
|
Address of the host the registry runs on. Defaults to 0.0.0.0.
|
|
|
|
|
|
|
|
|
|
* ``api_port``
|
|
|
|
|
|
|
|
|
|
Port the registry server listens on. Defaults to 9292.
|
|
|
|
|
|
|
|
|
|
* ``default_store``
|
|
|
|
|
|
|
|
|
|
The store that the Glance API server will use by default to store
|
|
|
|
|
images that are added to it. The default value is `filesystem`, and
|
|
|
|
|
possible choices are: `filesystem`, `swift`, and `s3`.
|
|
|
|
|
|
|
|
|
|
* ``filesystem_store_datadir``
|
|
|
|
|
|
|
|
|
|
Directory where the filesystem store can write images to. This directory
|
|
|
|
|
must be writeable by the user that runs ``glance-api``
|
|
|
|
|
|
|
|
|
|
.. todo::
|
|
|
|
|
|
|
|
|
|
Link to docs on the different stores when the documentation on Glance
|
|
|
|
|
stores is complete.
|
