Discussed in the Moby PR moby/moby#34895 (comment) (cc @mlaventure )

High-level engines such as Moby Core may need to parse the output of containerd --version.

I suggest JSONify containerd --version for machine readability.

before:

containerd github.com/containerd/containerd v1.0.0-beta.1

after:

{"name":"containerd","package":"github.com/containerd/containerd","version":"v1.0.0-beta.1"}

In future, we could easily add other fields (e.g. built-in plugins, Go runtime version) to this JSON output without breaking compatibility.