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OpenStack Glance

OpenStack Glance is the OpenStack image service that provides discovery, registration, storage, and delivery of disk and server images for cloud infrastructure (infrastructure-as-a-service).

  • Central image registry and delivery service for Virtual Machine (VM) and volume images (cloud infrastructure)
  • Supports multiple image back ends, including file systems and object storage (storage management)
  • Provides RESTful APIs for image discovery, upload, download, and metadata management (API-driven infrastructure)
  • Integrates with other OpenStack services such as Nova and Cinder for image provisioning workflows (cloud orchestration)
  • Offers pluggable architecture for image formats, locations, authentication, and storage drivers (extensible infrastructure platform)

More About OpenStack Glance

OpenStack Glance is the image management component of the OpenStack cloud platform, focused on storing, cataloging, and providing access to disk images and related metadata used by compute and storage services in Infrastructure-as-a-Service (IaaS) environments.

The primary function of Glance is to act as a centralized image repository and registry (cloud infrastructure), enabling operators and automation systems to upload, store, discover, and distribute VM images and volume snapshots across an OpenStack deployment. It exposes a RESTful Application Programming Interface (API) (API management) that allows other OpenStack services and external tools to perform operations such as image creation, listing, querying by metadata, and retrieval.

Glance supports multiple storage back ends (storage management), including file-based storage and object storage systems, configured through a pluggable driver model. This allows operators to align image storage with their existing storage platforms and durability or performance requirements. Images can be stored in a single back end or distributed across different locations, with Glance maintaining metadata and access information.

In typical enterprise use, Glance integrates with OpenStack Compute (Nova) and Block Storage (Cinder) (cloud orchestration). Nova uses Glance as the source for bootable images when launching VM instances, while Cinder can create or use volume images registered in Glance. This integration supports standardized base images, gold images, and application templates across projects and tenants in a cloud environment.

Glance implements a metadata and property system (configuration and asset cataloging) that allows tagging images with attributes such as Operating System (OS), architecture, hypervisor compatibility, and custom properties. This enables scheduling decisions in Nova and supports governance and compliance practices by classifying and controlling image usage.

The service relies on OpenStack Identity (Keystone) for authentication and authorization (identity and access management), enabling multi-tenant access control and quota policies around image creation and sharing. Administrators can define whether images are private, shared, or public within the cloud.

From an architectural and taxonomy perspective, OpenStack Glance is categorized as an image registry and catalog for cloud infrastructure, supporting virtual infrastructure lifecycle management. It functions as a core control-plane service in OpenStack deployments, interacting with compute, storage, and identity services through OpenStack’s standard APIs and extensible plug-in framework.