Support for configuring docker's data-root

[cumirror]

Your current KubeKey version

version.BuildInfo{Version:"1.1.0", GitCommit:"70671f7", GitTreeState:"", GoVersion:"go1.14.15"}

Describe this feature

In a production environment, user often mount additional disk for docker to use to avoid putting pressure on the system disk. After kk installs the k8s cluster, docker uses the default /var/lib/docker as the root directory. Hope kk can provide configuration options to enable the data-root configuration for docker.

Describe the solution you'd like

At present, kk can set parameters such as mirror in RegistryConfig. Maybe we can extend this structure to support data-root. When rendering the daemon.json template, set it to the docker configuration.

Additional information

No response

[24sama]

Thanks for your idea. We will consider your suggestion.