Getting an "operation not supported" error when trying to RUN something while building a docker image

Question

I'm trying to build a docker image with the following command:

docker build -f conf/Dockerfile -t my_app_name .

The Dockerfile starts with:

FROM ubuntu:14.04

COPY conf/pubkey pubkey
RUN echo 'deb http://downloads.skewed.de/apt/trusty trusty universe' >> /etc/apt/sources.list \
  && apt-key add pubkey \
  && rm pubkey

And it returns INFO[0000] operation not supported.

Regardless of what I put after RUN (even RUN echo 1 fails)

I tried running a shell in the intermediate docker image (docker run a7bb092… -it /bin/sh) but this just throws FATA[0000] Error response from daemon: Cannot start container a7bb092…: operation not supported

How can I fix this?

Answer 1

Well, turns out that if your machine had a kernel update but you didn't restart yet then docker freaks out. Restarting the machine fixed that. Oops.

Answer 2

This can happen if you do not have CONFIG_VETH selected in your kernel or don't have lxc and cgroup.

$ zcat /proc/config.gz | grep VETH
CONFIG_VETH=m

https://github.com/docker/docker/issues/7246