OpenStack Glance is an image service component of the OpenStack cloud computing platform. It provides a way to discover, register, and retrieve virtual machine (VM) images, such as operating system images and disk snapshots. Glance acts as a repository for these images, allowing users to store, manage, and share them across multiple OpenStack deployments.
Here are some key features and components of OpenStack Glance:
- Image Repository: Glance serves as a centralized repository for VM images. It allows users to store and manage various types of images, including system images (OS images), disk images, and snapshots.
- Image Discovery: Glance provides a discovery mechanism that allows users to search for available images based on different criteria, such as name, format, or tags. This makes it easier to find the desired images for launching instances.
- Image Formats: Glance supports multiple image formats, including RAW, VHD, VMDK, OVA, ISO, and qcow2. This enables users to upload and use images in different formats, depending on their requirements.
- Image Metadata: Glance allows users to attach metadata to images. Metadata includes information such as image name, description, architecture, operating system type, version, and other relevant details. This metadata helps users in identifying and managing the images effectively.
- Image Sharing: Glance enables image sharing between different users or projects within an OpenStack deployment. This facilitates collaboration and allows users to reuse images without the need for duplicating or uploading them again.
- Image Lifecycle Management: Glance supports image versioning, allowing users to create and manage multiple versions of the same image. It also provides mechanisms for image updating, deleting, and protection through access control policies.
- Image Caching: Glance has a caching mechanism that can be configured to cache frequently accessed images. This helps improve the performance and reduces the load on the underlying storage infrastructure.
- Integration with Other OpenStack Services: Glance integrates with other OpenStack components, such as Nova (compute service), Cinder (block storage), and Neutron (networking service). This integration allows users to seamlessly launch instances using the registered images and attach storage volumes.
Components of Openstack Glance:
Overall, Glance simplifies the management and distribution of VM images within an OpenStack environment. It provides a scalable and efficient way to handle image-related tasks, enabling users to deploy instances quickly and easily.