Chapter 5. OpenStack Image Service Installation
- 5.1. Image Service Overview
- 5.2. Image Service Requirements
- 5.3. Install the Image Service Packages
- 5.4. Create the Image Service Database
- 5.5. Configuring the Image Service
- 5.5.1. Configuration Overview
- 5.5.2. Create the Image Identity Records
- 5.5.3. Configure the Image Service Database Connection
- 5.5.4. Configure Image Service Authentication
- 5.5.5. Using the Object Storage Service for Image Storage
- 5.5.6. Configure the Firewall to Allow Image Service Traffic
- 5.5.7. Configure the Image Service to Use SSL
- 5.5.8. Populate the Image Service Database
- 5.5.9. Enable Image Loading Through the Local File System
- 5.6. Launch the Image API and Registry Services
- 5.7. Validate the Image Service Installation
5.1. Image Service Overview
The Image service acts as a registry for virtual disk images. Users can add new images or take a snapshot (copy) of an existing server for immediate storage. Snapshots can be used as back up or as templates for new servers. Registered images can be stored in the Object Storage service, as well as in other locations (for example, in simple file systems or external web servers).
The following image formats are supported:
- raw (unstructured format)
- aki/ami/ari (Amazon kernel, ramdisk, or machine image)
- iso (archive format for optical discs; for example, CD)
- qcow2 (Qemu/KVM, supports Copy on Write)
- vhd (Hyper-V, common for virtual machine monitors from VMware, Xen, Microsoft, VirtualBox, and others)
- vdi (Qemu/VirtualBox)
- vmdk (VMware)
Container formats can also be used by the Image service; the format determines the type of metadata stored in the image about the actual virtual machine. The following formats are supported.
- bare (no metadata is included)
- ovf (OVF format)
- aki/ami/ari (Amazon kernel, ramdisk, or machine image)
Table 5.1. Image Service components
| Component | Description |
|---|---|
|
openstack-glance-api
|
Handles requests and image delivery (interacts with storage back-ends for retrieval and storage). Uses the registry to retrieve image information (the registry service is never, and should never be, accessed directly).
|
|
openstack-glance-registry
|
Manages all metadata associated with each image.
|
|
Database
|
Stores image metadata.
|
|
RabbitMQ server (
rabbitmq-server)
|
Provides the AMQP message queue. This server (also used by Block Storage) handles the OpenStack transaction management, including queuing, distribution, security, management, clustering, and federation. Messaging becomes especially important when an OpenStack deployment is scaled and its services are running on multiple machines.
|