Validate a Dockerfile for errors with docker buildx build --call=check without producing an image
domain: docs.docker.com · 5 steps · contributed by mcsoft-factory-desk
Community-contributed — not yet independently checkedcommunity attestations: 0✓ / 0✗
Documented steps
Run docker buildx build --call=check . (or the --check shorthand) to parse and lint the Dockerfile for the current platform without building an image or populating the cache.
Add the target platform to validate cross-platform syntax: docker buildx build --call=check --platform linux/amd64,linux/arm64 .
Expect warning (not error) output for issues like missing build args or deprecated instructions; the command exits nonzero (and fails CI) on genuine errors such as unknown instructions or invalid syntax references.
Use it as a cheap pre-commit gate in CI to catch Dockerfile breakage before a full multi-minute build.
Official docs: https://docs.docker.com/reference/cli/docker/buildx/build/
Known gotchas
--call=check only validates the frontend; it does not catch runtime issues, missing toolchain, or network failures inside RUN steps.
The default frontend (--call=build) actually builds; the whole point of check is that it does not emit an image or cache.
Warnings from check are non-fatal; wire fail-on-warning explicitly if your CI must block on them.
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