Nameserver configuration in cloud-init isn't picked up

[cliksuresh18]

I am trying to create 2 ubuntu 22.04 VMs through cloud-init. The nameserver config in cloud-init is not reflecting in /etc/resolve.conf. Due to this, the dns resolution isn't working for the hosts in the same network.

output of cat /etc/netplan/50-cloud-init.yaml

network:
    version: 2
    ethernets:
        eth0:
            addresses:
            - 192.168.10.30/24
            match:
                macaddress: 0a:0b:30:d8:db:d3
            nameservers:
                addresses:
                - 192.168.1.10
                search:
                - localdomain
            routes:
            -   to: default
                via: 192.168.10.1
            set-name: eth0

Output of resolvectl status

Global
       Protocols: -LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
resolv.conf mode: stub

Link 2 (eth0)
    Current Scopes: DNS
         Protocols: +DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
Current DNS Server: 192.168.1.10
       DNS Servers: 192.168.1.10
        DNS Domain: localdomain

Link 3 (docker0)
Current Scopes: none
     Protocols: -DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported

output of cat /etc/resolv.conf

nameserver 127.0.0.53
options edns0 trust-ad
search localdomain

If I add the line nameserver 192.168.1.10 in the resolv.conf, the DNS resolution works.

I tried a few options but none of these works.

- Clear the cloud-init and restart
- change 50-cloud-init.yaml and reapply netplan
- Use DHCP instead of static ip

Is there anything else I can try to troubleshoot this.?

 

[cliksuresh18]

This is the error i get if I try to resolve. If I add nameserver 192.168.1.10 to resolv.conf file, the server is reachable

ubuntu@k8s-control-1:~$ ping k8s-control-2
ping: k8s-control-2: Temporary failure in name resolution[/CODE

 

[surepointit]

I have the same thing happening where the nameserver shows 127.0.0.53. Where you able to get this resolved?

 

[findus3000]

The same thing here for me, the name server is not set, although the search domain get´s set correctly in /etc/resolv.conf.

 

[findus3000]

The same thing here for me, the name server is not set, although the search domain get´s set correctly in /etc/resolv.conf.

forgot to mention: i am using Ubuntu 24.04.
Digging futher into this issue, i noticed that /etc/resolv.conf is a symlink to /run/systemd/resolve/stub-resolv.conf. Although the nameserver IP does not get set in stub-resolv.conf, i further noticed that there is also a resolv.conf in that directory. And there both nameserver and search domain get set correctly.
To my stupidity I have to admit that the DNS resolution always worked, i can resolve internal and external names successfully
Due to the missing entry in /etc/resolv.conf, I initially thought DNS resolution wouldn't work. It seems like the config in /run/systemd/resolve/resolv.conf is active.