DNS no longer working

timber

NicoB Ok but can you confirm it’s working with Docker 29.1.0?

NicoB

It worked for me, and I can now receive emails again.

In the meantime, I also adjusted the file:
/etc/docker/daemon.json
and stored the DNS there, but that didn’t help at first; I had to recreate the container.

My Host:
Debian 11
Docker-CE: 29.1.0-1

timber

NicoB I don’t see anything in my daemon.json that makes me confident to mess with it: {“ipv6”:true,“fixed-cidr-v6”:“fd00:dead:beef:c0::/80”,“experimental”:true,“ip6tables”:true}

Since recreating the containers didn’t work for John, I think I will sit tight until we have more insights or an official fix even.

These Docker updates seem to cause a lot of trouble. About a week ago, they broke Traefik und now Unbound..

bundyland

NicoB

Which commands have you used exactly?

Thanks a lot.

NicoB

I overwritten the following file:
/etc/docker/daemon.json
{ "ipv6": true, "fixed-cidr-v6": "fd00:dead:beef:c0::/80", "experimental": true, "ip6tables": true, "dns": ["1.1.1.1", "8.8.8.8"] }

and then recreated the containers with ‘docker compose down && docker compose up -d’

That’s it.

Before that, I tried a few other things, but nothing helped.

bundyland

Thanks a lot!

NicoB

I should perhaps mention that I reverted the change to daemon.json because it worked again without the change.

timber

NicoB As far as I understand, mailcow does its dns resolving through unbound so changing the DNS servers in Docker shouldn’t affect this. On my setup watchdog showed unbound as unhealthy so mailcow couldn’t resolve any dns queries which resulted in rejecting incoming emails. I’m glad it works again for you but it remains unclear why. According to John, recreating the containers didn’t fix it for him.

johncliffton

I can confirm to be working again after reverting to 29.0.4-1_debian.12_bookworm
Thanks everyone for your help!

chriscroome

This appears to the the issue?

moby/moby51614

A docker compose down then a reboot and a docker compose up -d appears to have resolved it for me…

timber

chriscroome Oh wow. They did it again.

esackbauer

timber
And I fear they will do it again… seems the official repo from Docker is cutting edge and not stable.

timber

esackbauer At least they fixed it fast. Docker 29.1.1 is just out. Mailcow is happy again.