fix(dockerfile): podman compose compatibility with BUILDPLATFORM

[nktnet1]

SUMMARY

Fixes #31488.

Using a different variable, TARGET_BUILDPLATFORM, inside the Dockerfile to avoid name conflict/redefining BUILDPLATFORM which is an issue in podman.

ARG TARGET_BUILDPLATFORM=${BUILDPLATFORM:-amd64}

TESTING INSTRUCTIONS

Run the command

podman compose -f docker-compose-non-dev.yml up --build

and observe that the error

Error: reading multiple stages: attempted to redefine "BUILDPLATFORM": invalid argument

Is no longer there.

ADDITIONAL INFORMATION

• Has associated issue:
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

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[sfirke]

This looks good to me, thanks for contributing it! Is there a risk / what size risk of breaking changes for someone who uses the current variable name in a workflow? If significant, I would say let's merge this during the upcoming breaking window (I think it would be excessive to say this requires a vote). If not, we can merge now IMO.

[mistercrunch]

would ARG TARGET_BUILDPLATFORM=${TARGET_BUILDPLATFORM:-${BUILDPLATFORM:-amd64}} be better? - haven't tested it?

I think it would provide a default if somehow both TARGET_BUILDPLATFORM and BUILDPLATFORM are not in context.

[nktnet1]

Thanks @mistercrunch - I can confirm that it does work, although I'm not sure if it's necessary. TARGET_BUILDPLATFORM was just a name I made up with the sole reason being that it's a different name to BUILDPLATFORM. Apologies if I've misunderstood though. Happy to make the change regardless

[mistercrunch]

oh why can't you use BUILDPLATFORM?

[nktnet1]

From #31488 - podman gives this error:

[mistercrunch]

I did a bit of research and this should not be an issue AFAICT. Especially if BUILDPLATFORM is always in context.

Looked a bit into podman, seems interesting but not sure whether it'd be beneficial for us to use as our build engine.

[mistercrunch]

Still on the fence but would require a line in UPDATING.md to notify release managers.

[nktnet1]

Thanks ＠mistercrunch (and ＠sfirke) - it doesn't look like podman is that widely used by users of apache/superset anyway (I only found 1-2 posts on it) so I'm happy to let this sit until more users are using podman + running into the issue (or just close the PR) and work off a fork.