Docker with a new nameserver

Question

How I can add new nameserver in /etc/resolv.conf (dockerfile)?

On my dockerfile I use:

FROM ubuntu:14.04

RUN echo \"nameserver 10.111.122.1         


        

Answer 1

The DNS configuration of a Docker container may be adjusted during the creation of the container and does not need to be hard-coded in the Docker image itself.

Passing a single DNS server to the container works by providing the --dns parameter:

$ docker run --rm --dns=8.8.8.8 

You're free to provide more than one DNS server and you can also define other DNS related options like the DNS search name or common DNS options:

$ docker run --rm --dns=8.8.8.8 --dns=8.8.4.4 --dns-search=your.search.domain --dns-opt=timeout:50 

If you pass cat /etc/resolv.conf as command to your container, you can easily verify that the passed DNS configuration options made it into the container's DNS configuration:

$ docker run --rm --dns=8.8.4.4 --dns=8.8.8.8 --dns-search=your.domain.name --dns-opt=timeout:50 alpine cat /etc/resolv.conf

search your.domain.name
nameserver 8.8.4.4
nameserver 8.8.8.8
options timeout:50

Please also refer to the docker run configuration which can be found at https://docs.docker.com/engine/reference/commandline/run/