How to use sudo inside a docker container?

Question

Normally, docker containers are run using the user root. I\'d like to use a different user, which is no problem using docker\'s USER directive. But this use

Answer 1

Just got it. As regan pointed out, I had to add the user to the sudoers group. But the main reason was I'd forgotten to update the repositories cache, so apt-get couldn't find the sudo package. It's working now. Here's the completed code:

FROM ubuntu:12.04

RUN apt-get update && \
      apt-get -y install sudo

RUN useradd -m docker && echo "docker:docker" | chpasswd && adduser docker sudo

USER docker
CMD /bin/bash