Where is the dns pod in "Contiv and Kubernetes" SandBox

[chungewa]

Hello

In this sandbox, i cant find the dns pod, how is the cluster dealing with service discovering?

Thanks a ton!

[root@netmaster ~]# kubectl get pods --all-namespaces -o wide
NAMESPACE     NAME                                    READY     STATUS    RESTARTS   AGE       IP           NODE
kube-system   contiv-api-proxy-52jwg                  1/1       Running   1          2h        10.10.20.1   netmaster
kube-system   contiv-etcd-r69kv                       1/1       Running   0          2h        10.10.20.1   netmaster
kube-system   contiv-netmaster-f04zj                  1/1       Running   1          2h        10.10.20.1   netmaster
kube-system   contiv-netplugin-0kfm0                  1/1       Running   0          2h        10.10.20.3   k8s-worker-2
kube-system   contiv-netplugin-2z02d                  1/1       Running   0          2h        10.10.20.2   k8s-worker-1
kube-system   contiv-netplugin-f0phz                  1/1       Running   0          2h        10.10.20.4   k8s-worker-3
kube-system   contiv-netplugin-wpr3c                  1/1       Running   0          2h        10.10.20.1   netmaster
kube-system   dummy-2088944543-n793h                  1/1       Running   0          2h        10.10.20.1   netmaster
kube-system   etcd-netmaster                          1/1       Running   0          2h        10.10.20.1   netmaster
kube-system   kube-apiserver-netmaster                1/1       Running   0          2h        10.10.20.1   netmaster
kube-system   kube-controller-manager-netmaster       1/1       Running   0          2h        10.10.20.1   netmaster
kube-system   kube-discovery-1769846148-gx8ch         1/1       Running   0          2h        10.10.20.1   netmaster
kube-system   kube-proxy-6x86k                        1/1       Running   0          2h        10.10.20.3   k8s-worker-2
kube-system   kube-proxy-d3k70                        1/1       Running   0          2h        10.10.20.2   k8s-worker-1
kube-system   kube-proxy-fnh3s                        1/1       Running   0          2h        10.10.20.1   netmaster
kube-system   kube-proxy-jgszz                        1/1       Running   0          2h        10.10.20.4   k8s-worker-3
kube-system   kube-scheduler-netmaster                1/1       Running   0          2h        10.10.20.1   netmaster
kube-system   kubernetes-dashboard-2521145884-q2d05   1/1       Running   0          2h        10.96.0.2    k8s-worker-3

Jason

[thodavie]

Hey! Hope you're enjoying the Sandbox!

When you deploy Contiv, the K8s DNS is removed. Contiv has it's own DNS.

You can hit Contiv for more details and the latest documentation.

[chungewa]

when i get the service:

[root@netmaster multi-tier]# kubectl get service -o wide --all-namespaces
NAMESPACE     NAME                   CLUSTER-IP      EXTERNAL-IP   PORT(S)         AGE       SELECTOR
default       frontend               10.101.5.87     <nodes>       80:32195/TCP    44m       app=guestbook,tier=frontend
default       kubernetes             10.96.0.1       <none>        443/TCP         1d        <none>
kube-system   kube-dns               10.96.0.10      <none>        53/UDP,53/TCP   1d        name=kube-dns
kube-system   kubernetes-dashboard   10.102.32.215   <nodes>       80:32465/TCP    1d        app=kubernetes-dashboard

sounds in our sandbox, cluster using kube-dns, but not contiv dns, am i right?

thx!

[zowu · Accepted solution]

Hi Chungewa,

We've removed kube-dns pod from deployment since Contiv has built-in DNS service in VXLAN mode. The associated kube-dns service has no active endpoint and cannot provide any DNS service. The advertised cluster-IP of kube-dns i.e. 10.96.0.10 was pre-configured by kubelet, and we may also delete it in our next release. 

Please change your /etc/resolv.conf like this in your pod:(suppose you are using default-net, and 10.96.0.2 is netmaster address)

echo "nameserver 10.96.0.2" > /etc/resolv.conf 

Thanks again for your interest on our Contiv sandbox.

Regards,

Bob

[chungewa]

Thanks,

thats just make sense

[Vallard Benincosa]

Note that the 1.1.0 version of contiv (not currently used in the sandbox today) with kubernetes 1.6+ does in fact allow the use of kube-dns and doesn't delete it.

[zowu]

We've upgraded Kubneretes to 1.6.7 and Contiv to latest 1.1.1.  And our sandbox now supports kube-dns pod.