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Announcements

Updates to Sandbox Reservation Internet Access Policy

Due to changes in our networking policies, we are updating the internet access policy within our sandbox reservation instances.
Hosts will no longer have internet access outbound.
This should not affect the overall functionality or access to the resources within the sandbox instances, connecting via VPN.

Keep Innovating!

DevNet Sandbox Team

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Cisco Employee

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

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

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1 ACCEPTED SOLUTION

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Highlighted
Cisco Employee

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

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

View solution in original post

6 REPLIES 6
Highlighted
Cisco Employee

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

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.

Highlighted
Cisco Employee

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

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!

Highlighted
Cisco Employee

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

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

View solution in original post

Highlighted
Cisco Employee

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

Thanks,

thats just make sense

Highlighted
Contributor

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

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.

Highlighted
Cisco Employee

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

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

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