Image — Glance

Glance is the OpenStack Image service. It provides a registry and delivery mechanism for virtual machine disk images, kernel images, ramdisks, and ISO files. It does not store images itself by default — it delegates persistence to a pluggable store backend (local filesystem, Swift, Ceph/RBD, S3, Cinder, or HTTP). Nova, Ironic, and other services retrieve images from Glance when provisioning compute resources.

Glance has been a core OpenStack service since the Bexar release (2011). The registry service (glance-registry) was deprecated in the Rocky release (2018) and removed in Train (2019). All metadata is now handled directly by the glance-api process.

When to Read This Skill

Deploying Glance for the first time or adding a new store backend
Uploading, importing, or managing VM images
Configuring image visibility (public, private, shared, community)
Understanding the interoperable image import workflow
Using image properties to control Nova scheduling or hardware configuration
Managing image metadata namespaces and property definitions
Setting up image caching on compute or API nodes
Troubleshooting stuck images (queued, saving, killed states)
Performing image conversion or decompression at import time
Managing image sharing between projects

Sub-Files

File	What It Covers
architecture.md	glance-api, store backends, image properties, visibility model, status lifecycle, metadef namespaces, protected images
operations.md	CLI and API: image upload, import, list, show, delete, set, save, sharing, property management, full config reference
internals.md	glance_store library, image caching, task API, import plugins, location strategy, delayed delete and scrubber, image conversion, image decompression

Quick Reference

# Upload a local image
openstack image create \
  --disk-format qcow2 \
  --container-format bare \
  --file ubuntu-24.04.qcow2 \
  --public \
  ubuntu-24.04

# List all images visible to your project
openstack image list

# Show image details
openstack image show ubuntu-24.04

# Import an image from a URL (web-download)
openstack image create \
  --disk-format qcow2 \
  --container-format bare \
  --uri https://cloud.example.com/ubuntu-24.04.qcow2 \
  --import \
  ubuntu-24.04

# Set image properties for hardware configuration
openstack image set --property hw_disk_bus=virtio --property hw_vif_model=virtio ubuntu-24.04

# Share an image with another project
openstack image add project ubuntu-24.04 <target-project-id>
openstack image member set --status accepted ubuntu-24.04 <target-project-id>

# Save (download) an image locally
openstack image save --file downloaded.qcow2 ubuntu-24.04

# Delete an image
openstack image delete ubuntu-24.04

Dependencies

Dependency	Purpose	Notes
Keystone	Authentication and service catalog	All Glance API calls validated against Keystone
MariaDB 10.6+ or PostgreSQL 14+	Image metadata database	Image data is stored in the configured backend, not the DB
Store backend (file / Swift / Ceph / S3 / Cinder)	Image data persistence	File store is default; Ceph RBD recommended for production HA
Apache httpd or Nginx	WSGI front-end for glance-api	mod_wsgi or uwsgi; direct eventlet server supported but not recommended
oslo.messaging / RabbitMQ	Task notifications and inter-service events	Required for task API and import workflow notifications
python-glanceclient	Python bindings	Used internally by Nova and other services
python-openstackclient	Unified CLI	Wraps the Glance v2 REST API

Releases Covered

This skill covers OpenStack 2025.1 (Epoxy), 2025.2, and 2026.1.

Glance release notes: https://docs.openstack.org/releasenotes/glance/