How you create /hadoop/dfs/name dir without ROOT user

In the dockerfiles of /namenode and /datanode you use the following command:

```RUN mkdir -p /hadoop/dfs/name```. However, when I also use the same command in a same kind of approach I receive an error that mkdir command access denied. I can over pass the error only if I use the command ```USER root``` first. But I don't see any similar approach in your scripts