Use alpine for small runtime images

Alpine keeps runtime images small.

Superseded

This record is no longer served as current advice. See containers-distroless-base.

ID	containers-alpine-base
Strength	should (warning)
Status	superseded
Scope	containers
Applies to	Dockerfile, **/Dockerfile
Tags	image-size
Updated	2025-03-01

Context

Debian-based images were several hundred megabytes and slow to pull.

Decision

Use alpine as the runtime base.

Consequences

musl differs from glibc in subtle ways, and the image still ships a shell and apk. Superseded by containers-distroless-base, which is smaller still and has neither.

Enforced by

No automated rule yet; reviewers and canon decide carry this one.

Read it from an agent with canon explain containers-alpine-base, or the canon://records/containers-alpine-base resource.