devthefuture-org/dockerfile-x

Top level ARG support

Closed this issue · 6 comments

davireis commented

The ARG parameter comes in two shapes. Either it is declared after a FROM statement, and has its scope limited to that stage, or it is declared before any FROM statement, and then it will be global. Because dockerfile-x can interleave the content of several files, some ARG may migrate from top level to stage scope. The answer here is to move every ARG which is local in a single file to the top of the resulting Dockerfile.

devthejo commented

I think I understand (tell me if it's not), you can handle this by putting ARG on top on root Dockerfile before any include, so this will let the possibility to globalize an ARG or not

bonitao commented

I cannot move the ARG to the top root Dockerfile because that root Dockerfile may be used as the root for different projects, and the ARG would make sense only in one of those projects. In other words, that breaks the include mechanism goal of serving as a way to model common dependencies.

devthejo commented

OK, understood, thanks for your feedback
I think the problem is what if there are default ARG in one local stage and another default for same named ARG in another stage, what should be the global default, eg:

FROM debian AS builder
ARG FOO=BAR

FROM debian AS server
ARG FOO=BAZ

but I see nothing that is opposed to redeclare the ARG key globally, eg

ARG FOO

FROM debian AS builder
ARG FOO=BAR

FROM debian AS server
ARG FOO=BAZ

I will implement this

devthejo commented

It's implemented and released just now, ready to use ;-)

@bonitao / @davireis

shinsenter commented

I think this fix is causing #16

  • 👍1
devthejo commented

the approach was not good and caused a regression: #16

the new approach is to only get ARG on top if the ARG is on top of the included Dockerfile (before FROM) and when the Dockerfile is included using FROM or --from, not INCLUDE (to let it agnostic of this).

Example:

# syntax = devthefuture/dockerfile-x
FROM ubuntu.dockerfile

ubuntu.dockerfile

ARG UBUNTU_VERSION=22.04
FROM ubuntu:$UBUNTU_VERSION
  • 👀1