scratch image
also: temporary image, disposable image, scratch container
A temporary, disposable container or virtual machine image used for testing, building, or development without affecting production systems. It can be created quickly and discarded after use.
A scratch image is a lightweight, throwaway copy of a system image—typically a container image or VM snapshot—used in isolated environments for experimentation and validation. Developers commonly create scratch images to test code changes, compile software, or verify configurations before deploying to production.
In container workflows, a scratch image often refers to using the minimal scratch base image (an empty filesystem) to build very small, security-hardened container images. For example, you might compile a Go binary on a standard Linux image, then copy only the binary into a scratch container to reduce size and attack surface.
Scratch images are also used in CI/CD pipelines for build verification: a fresh image is spun up, the build process runs, tests execute, and the image is discarded—ensuring reproducibility and preventing state pollution between builds.