Running Home Assistant in docker - DNS

Installation
1

Running Home Assistant in docker on a debian host.
I’m getting a strange issue with DNS.

From my understanding, the home assistant gets it’s DNS information from this file;
/usr/share/hassio/dns/corefile

When looking in this file, I see 4 DNS entries

.:53 {
    log
    hosts /config/hosts {
        fallthrough
    }
    forward . dns://<localip> dns://<localip> dns://8.8.8.8 dns://1.1.1.1 {
        health_check 10s
    }
}

Normally this wouldn’t be a problem, but it appears that Home Assistant does a ‘round robbin’ approach and makes use of the google DNS servers. (this is bad because I have devices that are only resolvable locally)

When I remove the google DNS servers from that config file, they are regenerated upon reboot.

how is this corefile created? and what is writing to it? and how can I stop 8.8.8.8 and 1.1.1.1 being amended to this file?

2

Are you running Home Assistant in docker or Hassio in docker? If you are running Hassio there are multiple other threads on this problem.

I am just asking because I run just Home Assistant in docker, and not Hassio and would like to know before I try to upgrade my docker container…

3

Just checked, im running hassio in docker.

4

Hi Nato,
I had the same problem, after about 24h i found the solution!
Somehow there now is a file in /usr/share/hassio called dns.json. this file deterimes the dns servers, if you change it there and reboot it will work :slight_smile:
Greetz, Jerry :v:

5

Hi Jerzeek,
I tried your suggestion and modified dns.json to the following;

{
  "servers": [
    "dns://10.5.1.4",
    "dns://10.5.1.5"
  ],
  "version": "1"
}

However, after a reboot my /usr/share/hassio/dns/corefile is still showing;

.:53 {
    log
    hosts /config/hosts {
        fallthrough
    }
    forward . dns://10.5.1.4 dns://10.5.1.5 dns://8.8.8.8 dns://1.1.1.1 {
        health_check 10s
    }
}

It must be pulling those additional DNS servers from somewhere else. :frowning:

6

Yeah I had the same, but since my personal dns was first it was working. let me know if you find a better solution. Also I dont know why it broke overnight, do you?

7

There are a lot of threads about these recent dns issues. It’s a known bug and is being worked on.

8

Because the hassio-supervisor was automatically updated in the last 24 hours.

9

Found the reported bug if anyone is interested.

https://github.com/home-assistant/hassio/pull/1238

10

That file is persistent across reboots (hass.io/docker/debian) for me.