46 lines
1.8 KiB
ReStructuredText
46 lines
1.8 KiB
ReStructuredText
======================
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Image service overview
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======================
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The OpenStack Image service is central to Infrastructure-as-a-Service
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(IaaS) as shown in :ref:`get_started_conceptual_architecture`. It accepts API
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requests for disk or server images, and metadata definitions from end users or
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OpenStack Compute components. It also supports the storage of disk or server
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images on various repository types, including OpenStack Object Storage.
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A number of periodic processes run on the OpenStack Image service to
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support caching. Replication services ensure consistency and
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availability through the cluster. Other periodic processes include
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auditors, updaters, and reapers.
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The OpenStack Image service includes the following components:
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glance-api
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Accepts Image API calls for image discovery, retrieval, and storage.
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glance-registry
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Stores, processes, and retrieves metadata about images. Metadata
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includes items such as size and type.
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.. warning::
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The registry is a private internal service meant for use by
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OpenStack Image service. Do not expose this service to users.
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Database
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Stores image metadata and you can choose your database depending on
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your preference. Most deployments use MySQL or SQLite.
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Storage repository for image files
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Various repository types are supported including normal file
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systems, Object Storage, RADOS block devices, HTTP, and Amazon S3.
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Note that some repositories will only support read-only usage.
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Metadata definition service
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A common API for vendors, admins, services, and users to meaningfully
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define their own custom metadata. This metadata can be used on
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different types of resources like images, artifacts, volumes,
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flavors, and aggregates. A definition includes the new property's key,
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description, constraints, and the resource types which it can be
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associated with.
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