I have kubernetes 1.13 running on Ubuntu 16.04.5 with flannel as the networking model. I have one master node and one worker node. I installed everything via kubeadm.
The problem is that when running nslookup, the name doesn’t always resolve or rather it hardly ever resolves. Perhaps 1 in 5 attempts will resolve.
kubectl exec -ti busybox -- nslookup postgres.kong Server: 10.96.0.10 Address 1: 10.96.0.10 Name: postgres.kong Address 1: 192.168.0.18 postgres-0.postgres.kong.svc.cluster.local
and then immediately running it again outputs as follows
kubectl exec -ti busybox -- nslookup postgres.kong Server: 10.96.0.10 Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local nslookup: can't resolve 'postgres.kong' command terminated with exit code 1
The busybox I am using is version 1.28 as I know about the dns issues with versions > 1.28
Any ideas on what could be causing the intermittent resolution?
After some investigation, it seems that the coredns pod running on the master node isn’t receiving the DNS records for new pods.
Any ideas on a fix for that? Google has not been very fruitful with the updated issue.