Setting up CoreDns Provider

Owned by Neha Jain
Last updated: Mar 06, 2018
3 min read



Kubernetes Federation supports following dns providers -

  • gcloud

  • aws

  • coredns

This page talks about setting up coredns provider for Kubernetes Federation. This needs to be executed on federation master node. The steps are taken from below link-

https://kubernetes.io/docs/tasks/federation/set-up-coredns-provider-federation/

This page is for information only and is not followed for setup. We are installing "coredns" as an add-on during kubernetes cluster installation.



Installing etcd charts

ubuntu@k8s-kubefed:~# helm install --namespace kube-system --name etcd-operator stable/etcd-operator
 
# Sample output start
NAME: etcd-operator
LAST DEPLOYED: Wed Jan 17 10:15:14 2018
NAMESPACE: kube-system
STATUS: DEPLOYED
RESOURCES:
==> v1/ServiceAccount
NAME SECRETS AGE
etcd-operator-etcd-operator-etcd-backup-operator 1 <invalid>
etcd-operator-etcd-operator-etcd-operator 1 <invalid>
etcd-operator-etcd-operator-etcd-restore-operator 1 <invalid>
==> v1beta1/ClusterRole
NAME AGE
etcd-operator-etcd-operator-etcd-operator <invalid>
==> v1beta1/ClusterRoleBinding
NAME AGE
etcd-operator-etcd-operator-etcd-backup-operator <invalid>
etcd-operator-etcd-operator-etcd-operator <invalid>
etcd-operator-etcd-operator-etcd-restore-operator <invalid>
==> v1/Service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
etcd-restore-operator ClusterIP 10.100.70.132 <none> 19999/TCP <invalid>
==> v1beta1/Deployment
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
etcd-operator-etcd-operator-etcd-backup-operator 1 1 1 0 <invalid>
etcd-operator-etcd-operator-etcd-operator 1 1 1 0 <invalid>
etcd-operator-etcd-operator-etcd-restore-operator 1 1 1 0 <invalid>
 
NOTES:
1. etcd-operator deployed.
If you would like to deploy an etcd-cluster set cluster.enabled to true in values.yaml
Check the etcd-operator logs
export POD=$(kubectl get pods -l app=etcd-operator-etcd-operator-etcd-operator --namespace kube-system --output name)
kubectl logs $POD --namespace=kube-system
# Sample output end
 
# Upgrade etc-operator and enable clustering.
ubuntu@k8s-kubefed:~# helm upgrade --namespace kube-system --set cluster.enabled=true etcd-operator stable/etcd-operator
 
# Sample output start
Release "etcd-operator" has been upgraded. Happy Helming!
LAST DEPLOYED: Wed Jan 17 10:16:33 2018
NAMESPACE: kube-system
STATUS: DEPLOYED
RESOURCES:
==> v1beta1/ClusterRole
NAME                                       AGE
etcd-operator-etcd-operator-etcd-operator  24s
==> v1beta1/ClusterRoleBinding
NAME                                               AGE
etcd-operator-etcd-operator-etcd-backup-operator   24s
etcd-operator-etcd-operator-etcd-operator          24s
etcd-operator-etcd-operator-etcd-restore-operator  24s
==> v1/Service
NAME                   TYPE       CLUSTER-IP     EXTERNAL-IP  PORT(S)    AGE
etcd-restore-operator  ClusterIP  10.100.70.132  <none>       19999/TCP  24s
==> v1beta1/Deployment
NAME                                               DESIRED  CURRENT  UP-TO-DATE  AVAILABLE  AGE
etcd-operator-etcd-operator-etcd-backup-operator   1        1        1           1          24s
etcd-operator-etcd-operator-etcd-operator          1        1        1           1          24s
etcd-operator-etcd-operator-etcd-restore-operator  1        1        1           1          24s
==> v1/ServiceAccount
NAME                                               SECRETS  AGE
etcd-operator-etcd-operator-etcd-backup-operator   1        24s
etcd-operator-etcd-operator-etcd-operator          1        24s
etcd-operator-etcd-operator-etcd-restore-operator  1        24s
 
NOTES:
1. etcd-operator deployed.
  If you would like to deploy an etcd-cluster set cluster.enabled to true in values.yaml
  Check the etcd-operator logs
    export POD=$(kubectl get pods -l app=etcd-operator-etcd-operator-etcd-operator --namespace kube-system --output name)
    kubectl logs $POD --namespace=kube-system
 
# Sample output end



Verify objects created and running

#Now, verify the new pods
ubuntu@k8s-kubefed:~# kubectl get pods --all-namespaces | grep "etcd-operator"
# Sample output
kube-system   etcd-operator-etcd-operator-etcd-backup-operator-5d59fdf4frbswb   1/1       Running   0          1m
kube-system   etcd-operator-etcd-operator-etcd-operator-84f5ddddbf-vsjcj        1/1       Running   0          1m
kube-system   etcd-operator-etcd-operator-etcd-restore-operator-d8b667cdb47dp   1/1       Running   0          1m
 
#Now, verify the new Service Accounts
ubuntu@k8s-kubefed:~# kubectl get sa --all-namespaces | grep "etcd-operator"
# Sample output
kube-system   etcd-operator-etcd-operator-etcd-backup-operator    1         7m
kube-system   etcd-operator-etcd-operator-etcd-operator           1         7m
kube-system   etcd-operator-etcd-operator-etcd-restore-operator   1         7m
 
#Now, verify the new Cluster Role Binding 
ubuntu@k8s-kubefed:~# kubectl get clusterrolebinding  --all-namespaces | grep "etcd-operator"
# Sample output
etcd-operator-etcd-operator-etcd-backup-operator    9m
etcd-operator-etcd-operator-etcd-operator           9m
etcd-operator-etcd-operator-etcd-restore-operator   9m
 
 
#Now, verify the new deployments
ubuntu@kk8s-kubefed:~# kubectl get deployment --all-namespaces | grep "etcd-operator"
# Sample output
kube-system   etcd-operator-etcd-operator-etcd-backup-operator    1         1         1            1           12m
kube-system   etcd-operator-etcd-operator-etcd-operator           1         1         1            1           12m
kube-system   etcd-operator-etcd-operator-etcd-restore-operator   1         1         1            1           12m
 
 
#Now, verify the new service
ubuntu@k8s-kubefed:~# kubectl get service --all-namespaces | grep "operator"
# Sample output
kube-system   etcd-restore-operator   ClusterIP   10.103.24.135   <none>        19999/TCP       19m



Deploying CoreDns

ubuntu@k8s-kubefed:~# cat > Values.yaml << EOF
isClusterService: false
serviceType: "NodePort"
middleware:
  kubernetes:
    enabled: false
  etcd:
    enabled: true
    zones:
    - "example.com."
    endpoint: "http://etcd-cluster.kube-system:2379"
EOF
  
ubuntu@k8s-kubefed:~# helm install --namespace kube-system --name coredns -f Values.yaml stable/coredns
NAME:   coredns
LAST DEPLOYED: Mon Jan 29 17:43:06 2018
NAMESPACE: kube-system
STATUS: DEPLOYED
RESOURCES:
==> v1/ConfigMap
NAME             DATA  AGE
coredns-coredns  1     <invalid>
==> v1/Service
NAME             TYPE      CLUSTER-IP     EXTERNAL-IP  PORT(S)                                   AGE
coredns-coredns  NodePort  10.109.54.134  <none>       53:30878/UDP,53:30878/TCP,9153:32108/TCP  <invalid>
==> v1beta1/Deployment
NAME             DESIRED  CURRENT  UP-TO-DATE  AVAILABLE  AGE
coredns-coredns  1        1        1           0          <invalid>
==> v1/Pod(related)
NAME                              READY  STATUS             RESTARTS  AGE
coredns-coredns-5fc6cdb5d7-82trc  0/1    ContainerCreating  0         <invalid>
 
NOTES:
CoreDNS is now running in the cluster.
It can be accessed using the below endpoint
  export NODE_PORT=$(kubectl get --namespace kube-system -o jsonpath="{.spec.ports[0].nodePort}" services coredns-coredns)
  export NODE_IP=$(kubectl get nodes --namespace kube-system -o jsonpath="{.items[0].status.addresses[0].address}")
  echo "$NODE_IP:$NODE_PORT"
It can be tested with the following:
1. Launch a Pod with DNS tools:
kubectl run -it --rm --restart=Never --image=infoblox/dnstools:latest dnstools
2. Query the DNS server:
/ # host kubernetes
 
ubuntu@k8s-kubefed:~#



Verify CoreDns pod and other objects are running as expected

#Now, verify the new pods
ubuntu@k8s-kubefed:/# kubectl get pods --all-namespaces | grep coredns
NAMESPACE     NAME                                                              READY     STATUS    RESTARTS   AGE
kube-system   coredns-coredns-798f955756-z5bfm  
  
  
#Now, verify the new deployments
ubuntu@k8s-kubefed:/# kubectl get deployment --all-namespaces  | grep coredns
NAMESPACE     NAME                                                DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
kube-system   coredns-coredns                                     1         1         1            1           56s
  
#Now, verify the new service
ubuntu@k8s-kubefed:/# kubectl get svc --all-namespaces | grep coredns
NAMESPACE     NAME                    TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)                                    AGE
kube-system   coredns-coredns         NodePort    10.97.177.10    <none>        53:30099/UDP,53:30099/TCP,9153:32673/TCP   2m
 
 
ubuntu@k8s-kubefed:~$ kubectl get configmap --all-namespaces| grep coredns
NAMESPACE     NAME                                 DATA      AGE
kube-system   coredns-coredns                      1         3m
kube-system   coredns.v1                           1         3m
 
 
  

If you are interested knowing more details about coredns configuration,  run the following commands.

root@kubefed-1:~# kubectl -n kube-system get configmap coredns-coredns -o yaml
apiVersion: v1
data:
  Corefile: |-
    .:53 {
        cache 30
        errors
        health
        kubernetes cluster.local 10.3.0.0/24
        loadbalance round_robin
        prometheus 0.0.0.0:9153
        proxy . /etc/resolv.conf
    }
kind: ConfigMap
metadata:
  creationTimestamp: 2018-01-29T22:43:10Z
  name: coredns-coredns
  namespace: kube-system
  resourceVersion: "1823"
  selfLink: /api/v1/namespaces/kube-system/configmaps/coredns-coredns
  uid: c80b6d98-0545-11e8-8bce-fa163e155847
root@kubefed-1:~# kubectl -n kube-system get configmap coredns.v1 -o yaml
apiVersion: v1
data:
  release: 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
kind: ConfigMap
metadata:
  creationTimestamp: 2018-01-29T22:43:10Z
  labels:
    MODIFIED_AT: "1517265786"
    NAME: coredns
    OWNER: TILLER
    STATUS: DEPLOYED
    VERSION: "1"
  name: coredns.v1
  namespace: kube-system
  resourceVersion: "1831"
  selfLink: /api/v1/namespaces/kube-system/configmaps/coredns.v1
  uid: c8096702-0545-11e8-8bce-fa163e155847
root@kubefed-1:~#


Create coredns-provider config

This custom coredns-provider.conf will be used to deploy federation.

ubuntu@k8s-kubefed:~# cat > $HOME/coredns-provider.conf << EOF
[Global]
etcd-endpoints = http://etcd-cluster.kube-system:2379
zones = example.com.
EOF



Need to delete/re-install coredns? 

Below command can be used to delete coredns release. This step may be followed only if there's a need to re-install coredns.

ubuntu@kk8s-kubefed:~# helm del --purge coredns
release "coredns" deleted
root@kubefed-4:~#