dockerprivilegesnice

How can I set negative niceness of a docker process?

I have a testenvironment for code in a docker image which I use by running bash in the container:

me@host$ docker run -ti myimage bash

Inside the container, I launch a program normally by saying

root@docker# ./myprogram

However, I want the process of myprogram to have a negative niceness (there are valid reasons for this). However:

root@docker# nice -n -7 ./myprogram
nice: cannot set niceness: Permission denied

Given that docker is run by the docker daemon which runs as root and I am root inside the container, why doesn't this work and how can force a negative niceness?

Note: The docker image is running debian/sid and the host is ubuntu/12.04.

Solution

  • Try adding

    --privileged=true

    to your run command.

    [edit] privileged=true is the old method. Looks like 

    --cap-add=SYS_NICE

    Should work as well.