Image Layer

Go up to Terms and Definitions

An Image Layer is a controlled set of additions, removals, or modifications applied to a source Machine Image to produce a derived Machine Image.

The layer may change packages, files, services, users, security settings, runtime components, policies, configuration, or other image content.

Image Layers support separation of concerns by allowing operating-system installation, guest preparation, security hardening, and workload capabilities to evolve as distinct controlled stages.

Within Crucible, each Image Layer builds on the output of a preceding layer and contributes to the Provenance of the resulting Machine Image.

controlled set of additions, removals, or modifications applied to a source machine image to produce a derived machine image

Generalized from layered machine-image, container-image, configuration-management, and image-build usage and specialized for the Crucible architecture and operational model.

An Image Layer may refer to a logical build stage rather than a storage-format layer. The term does not require use of a container-image filesystem or any particular image technology.

Applying an Image Layer produces a new image state. The source image remains a distinct artifact.

A Crucible image workflow applies an operating-system layer, a guest-configuration layer, a security-hardening layer, and a Kubernetes capability layer. Each Image Layer produces the source image for the next stage.