Skaffold multi-platform / multi-architecture builds using docker + buildx and a custom buildCommand

skaffold.yaml

apiVersion: skaffold/v2beta28
kind: Config
metadata:
  name: abcdef
build:
  artifacts:
    - image: ghcr.io/lg/abcdef
      custom:
        buildCommand: |   # build for multiple platforms
          if ! docker buildx inspect skaffold-builder >/dev/null 2>&1; then docker buildx create --name skaffold-builder --platform $PLATFORMS; fi
          docker buildx build --builder skaffold-builder --platform $PLATFORMS -t $IMAGE $($PUSH_IMAGE && echo '--push') "$BUILD_CONTEXT"
      platforms: ["linux/amd64", "linux/arm64"]
  tagPolicy:
    sha256: {}
deploy:
  kubectl:
    manifests:
      - some-kubernetes-file.yaml