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FROM argument is not declared.
PropertyValue
SeverityWarning
CategoryCorrectness
DefaultEnabled

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Description

This rule warns for cases where you are consuming an undefined build argument in FROM instructions. Interpolating build arguments in FROM instructions can be a good way to add flexibility to your build. However, if the argument is never declared with ARG, the variable silently resolves to an empty string, which is almost certainly not the intended behavior. This check also tries to detect and warn when a FROM instruction references misspelled built-in build arguments, like BUILDPLATFORM.

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Examples

Bad: 
FROM node:22${VARIANT} AS jsbuilder
Good: 
ARG VARIANT="-alpine3.20"
FROM node:22${VARIANT} AS jsbuilder
You can also pass the argument at build time: 
docker buildx build --build-arg ALPINE_VERSION=edge .

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Reference