Format output from docker CLI

Output from various commands of Docker CLI can be manipulated with Go templates using --format.

Normal docker ps output

> docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                    NAMES
3fe2829131c6        ghost:latest        "/entrypoint.sh npm s"   4 days ago          Up 17 seconds       0.0.0.0:2368->2368/tcp   ghost

If we want only Names and Command, we can use:

> docker ps --format "\t"
ghost "/entrypoint.sh npm s"

Output can be manupulated by template functions:

> docker ps --format "\t"
Ghost "/ENTRYPOINT.SH NPM S"

More info on template functions at https://docs.docker.com/engine/admin/formatting/