The ror generated Dockerfile does not build

[HaukeBartsch]

Running 'docker build...' creates an error message that indicates that external computers (like Debians repository) could not be found. Even a simple 'apt update' fails inside the docker environment.

The reason for the behavior was that a) DNS needed to be setup correctly on the machine used to build the image (add an accessible DNS in /etc/default/docker) and b) that the Dockerfile did not contain the proxy settings used on the machine that build the container.

DNS in /etc/default/docker:
DOCKER_OPTS="--dns 8.8.8.8"

Dockerfile:
ENV http_proxy="http://proxy.ihelse.net:3128"
ENV https_proxy="https://proxy.ihelse.net:3128"

[HaukeBartsch]

Using the above settings for the proxy 'apt update' and 'conda update conda' started to work again during 'docker build'.

[ehodneland]

You also need to restart docker: sudo systemctl restart docker