Kubernetes version: v1.26.2
Cloud being used: bare-metal
Installation method: kubeadm
CNI Flannel latest
CRI docker with Mirantis cri-dockerd as Docker Engine shim
K8s node is Host Ubuntu 22.04
My host can nslookup app.mydomain.com to a public IP address 1.2.3.4
I create a dnsutils pod and try nslookup with it
root@dnsutils:/# nslookup
> app.mydomain.com
Server: 10.96.0.10
Address: 10.96.0.10#53
** server can't find app.mydomain.com: NXDOMAIN
But it can resolve other domain normally
> google.com
Server: 10.96.0.10
Address: 10.96.0.10#53
Non-authoritative answer:
Name: google.com
Address: 172.217.31.14
How can I troubleshoot it ?
I cannot get certificate from cert-manager because my challenges complain that it cannot resolve app.mydomain.com to IP address
kubectl challenges -o wide
NAME STATE DOMAIN REASON AGE
app-tls-jv6lp-4092342631-2629679118 pending app.mydomain.com Waiting for HTTP-01 challenge propagation: failed to perform self check GET request 'http://app.mydomain.com/.well-known/acme-challenge/92ssMS-tILGY-a1SJ88UrkXXlNeN69sTXEoTTpY4cnY': Get "http://app.mydomain.com/.well-known/acme-challenge/92ssMS-tILGY-a1SJ88UrkXXlNeN69sTXEoTTpY4cnY": dial tcp: lookup app.mydomain.com on 10.96.0.10:53: no such host 3m58s
Please give me some advice, thank you very much.