That’s the last beta of this edition of Windows Server before it’s released to manufacturing. In the interim, Docker plans to ensure its ecosystem supports Windows Server, both in the OS itself and elsewhere.
The new Docker beta for Windows Server rolls in a couple of features vital to making Windows a first-class citizen of the Docker world. For one, Windows images on Docker Hub now have full support for the
pull commands, meaning Docker Hub ought to start featuring more Windows-specific images to use.
Another potentially major addition is a prototype of the ability to to perform multi-platform builds, pushes, and pulls for Docker images designed for multiple OSes and CPU architectures.
This isn’t done by packing multiple binary images into a single container, a la the Macintosh Universal Binary concept. Instead, the Docker Image Manifest — the file format that describes what’s inside a given image — now supports storing metadata about the CPU architecture and OS for the app in question. Pull requests sent to the Docker registry serve up the version that matches the client.
Building the apps for the appropriate platform, though, is entirely up to the developer and the language/runtime combo they’re using. Go, the language Docker is written in, does support cross-compilation , but Go is hardly the only language Docker apps are likely to be written in.
Still, it’s a major step toward having a culture of software use and distribution for Docker where the different platforms that use it are encouraged to make use of common resources, rather than similar ones built in parallel.