[chusk3]

You make great points about the need for customization and the boundaries of solutions that aren't based on Dockerfiles. Our approach to that problem is twofold, though both parts are still only in the planning stage:

* eventually providing an 'eject' mechanism to create the matching Dockerfile for a given project. this serves as a basis for any customization you might need, as well as a base language that many existing tools can understand.

* making it easy to include arbitrary image layers by reference in your container through a syntax like `<ContainerLayer Include="<layer SHA ref>" />`. This makes it easy to grab already-built components and inject them into your build.

I entirely agree with your summary. More choices, but all built on the same standard foundation :)