Docker build: interaction with host's network manager for DNS settings

[rimelek (Ákos Takács)]

I wrote about DNS today, and it seems the same is true for docker build

VM Migration with Pre-installed Docker Results in Slow Performance

It is a little bit more complicated. I remembered it copied the resolv.conf to the docker data root for the new container and mounted that copy, except when it was the stub resolver, because it always mounts something that should work in a container. Testing that now, I see that when I have systemd and I use the stub resolver, it mounts /run/systemd/resolve/resolv.conf and I see this in the logs: Apr 09 18:53:52 docker-vm-noble dockerd[3887]: time="2025-04-09T18:53:52.799236585+02:00" level=i…

So unless you restart the docker daemon DNS changes will not be updated for docker build.