docker elevate user priviledges

I'm trying to sudo for a node install:

 sudo npm install -g grunt
 sudo npm install -g grunt-cli
 sudo npm install -g bower

The commands error stating to run as an administrative user. How do I do that in the Dockerfile?

 RUN npm install -g grunt
 #RUN ln -s  /home/dev/spikes/node-esjs-master/node_modules/grunt  /usr/bin/grunt

 RUN npm install -g grunt-cli
 #RUN ln -s  /home/dev/spikes/node-esjs-master/node_modules/grunt-cli  /usr/bin/grunt-cli

 RUN npm install -g bower
 #RUN ln -s  /home/dev/spikes/node-esjs-master/node_modules/bower  /usr/bin/bower

I don't actually try to sudo in the docker commands...I have after connecting to the container but when prompted for the password I don't know it. I tried to create a sym link but couldn't get that to work. My apologies if this is basic in nature - new environments for me :-).

Thanks!

You don't need to use sudo because all commands in the dockerfile are executed as root. A sample Dockerfile to install those software (Ubuntu Thrusty as base):

FROM ubuntu:14.04

RUN apt-get update
RUN apt-get install -y nodejs npm

RUN npm install -g grunt
RUN npm install -g grunt-cli
RUN npm install -g bower

The same applies for the run command:

$ sudo docker run my_awesome_image whoami
root