nslookup kubernetes.default is stuck whereas nslookup kubernetes works fine

[msavlani]

Hi,

I am facing weird issues Kubernetes 1.5.2

Its a single 2 nodes cluster which is setup using "https://kubernetes.io/docs/getting-started-guides/centos/centos_manual_config/"

then i created skydns pods.

[root@masterhost ~]# kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
kube-dns-v20-jm7x7 3/3 Running 0 2h
kubernetes-dashboard-255567031-7dn4l 1/1 Running 44 11d

[root@mwhlvatd2d2 ~]# kubectl get services -n kube-system
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kube-dns 10.254.0.10 53/UDP,53/TCP 2h
kubelet None 10250/TCP 8d
kubernetes-dashboard 10.254.25.228 80:31000/TCP 24d

I created one busybox pod and tried to do nslookup for kubernetes service as follows

It worked fine.
[root@masterhost ~]# kubectl exec -ti busybox1 -- nslookup kubernetes
Server: 10.254.0.10
Address 1: 10.254.0.10 kube-dns.kube-system.svc.cluster.local

Name: kubernetes
Address 1: 10.254.0.1 kubernetes.default.svc.cluster.local

Then i did nslookup for kubernetes.default
[root@masterhost ~]# kubectl exec -ti busybox1 -- nslookup kubernetes.default
Server: 10.254.0.10
Address 1: 10.254.0.10 kube-dns.kube-system.svc.cluster.local

---- Here it got stuck for some time and then returned following error ;

nslookup: can't resolve 'kubernetes.default'

Expected result

[root@masterhost ~]# kubectl exec -ti busybox1 -- nslookup kubernetes.default.svc.cluster.local
Server: 10.254.0.10
Address 1: 10.254.0.10 kube-dns.kube-system.svc.cluster.local

Name: kubernetes.default.svc.cluster.local
Address 1: 10.254.0.1 kubernetes.default.svc.cluster.local

Any help here is appreciated.

[William Yang]

Can confirm. I'm having this issue too.

NAME="Container Linux by CoreOS"
ID=coreos
VERSION=1353.8.0
VERSION_ID=1353.8.0
BUILD_ID=2017-05-30-2322
PRETTY_NAME="Container Linux by CoreOS 1353.8.0 (Ladybug)"
ANSI_COLOR="38;5;75"
HOME_URL="https://coreos.com/"
BUG_REPORT_URL="https://issues.coreos.com"

Clean installation following the guide.