Should info/warn on FROM --platform=$BUILDPLATFORM

[skyzyx]

• This is a bug report
• This is a feature request
• I searched existing issues before opening this one

Expected behavior

Specifying FROM --platform=$BUILDPLATFORM should be flagged as (a) syntactically-valid, but (b) probably not what you want if you're building a multi-platform image.

Actual behavior

No info/warning on this.

Steps to reproduce the behavior

Version

Haskell Dockerfile Linter 2.12.0

Dockerfile

# syntax=docker/dockerfile:1
FROM --platform=$BUILDPLATFORM alpine:3.18

Output

None.

Additional environment details (OS, stack version, etc.)

• macOS 14.2β
• Installed via Homebrew
• Docker version 24.0.6, build ed223bc

[alexanderbazhenoff]

Have the same feature request to ignore FROM line, because in our ansible tests we template our dockerfile.j2 like:

FROM {{ item.image }}

Is it possible to ignore the whole line or switch to a more relaxed FROM value?