DNS troubleshooting

DNS resolution for pods

Driver Container failed to access archive.ubuntu.com

Issue:

Driver Container logs display the following error messages:

Troubleshooting:

follow the steps located here: https://kubernetes.io/docs/tasks/administer-cluster/dns-debugging-resolution/ to troubleshoot DNS pod resolution.

To install the dnsutils pod, launch the command:

kubectl apply -f https://k8s.io/examples/admin/dns/dnsutils.yaml

In a working CNS deployment, you should have an output similar to below:

nvidia@ipp1-1394:~$ kubectl exec -i -t dnsutils -- nslookup archive.ubuntu.com
Server:		10.96.0.10
Address:	10.96.0.10#53

Non-authoritative answer:
Name:	archive.ubuntu.com
Address: 91.189.91.82
Name:	archive.ubuntu.com
Address: 185.125.190.82
Name:	archive.ubuntu.com
Address: 185.125.190.83
Name:	archive.ubuntu.com
Address: 185.125.190.81
Name:	archive.ubuntu.com
Address: 91.189.91.81
Name:	archive.ubuntu.com
Address: 91.189.91.83
Name:	archive.ubuntu.com
Address: 2620:2d:4002:1::103
Name:	archive.ubuntu.com
Address: 2620:2d:4000:1::101
Name:	archive.ubuntu.com
Address: 2620:2d:4002:1::102
Name:	archive.ubuntu.com
Address: 2620:2d:4002:1::101
Name:	archive.ubuntu.com
Address: 2620:2d:4000:1::103
Name:	archive.ubuntu.com
Address: 2620:2d:4000:1::102

Note that Name must be exactly 'archive.ubuntu.com':

Name: archive.ubuntu.com

If you get a different output, it is recommended to fix the root cause (check with the team in charge of the DNS server. They may have created an entry for the archive.ubuntu.com and if this is the case, they must remove it).