Kubernetes 1.10.0 multi-master installation with 3 Master and 3 Slave nodes installation and configuration with CentOS7 and SSL - Installation of kube-dns and testing

Creation of kubernetes kube-dns service

wget  https://storage.googleapis.com/kubernetes-the-hard-way/kube-dns.yaml

Here this file is edited to set the value of the clutserIP for the DNS service.

clusterIP: 100.65.0.10

kubectl create -f kube-dns.yaml

service "kube-dns" created

serviceaccount "kube-dns" created

configmap "kube-dns" created

deployment.extensions "kube-dns" created

Testing if kube-dns service is working properly

Please note that as JQ command is used, in the minimal install of CentOS7 JQ is not there. Also this is available from the EPEL repo for CentOS.

Installation of JQ

yum -y install epel-release

yum clean all

rm -rf /var/cache/yum

yum -y install jq

yum -y remove epel-release

yum clean all

rm -rf /var/cahce/yum

Creation of a BusyBox deployment to test the DNS

kubectl run busybox --image=busybox --command -- sleep 3600

kubectl get pods -l run=busybox

POD_NAME=$(kubectl get pods -l run=busybox -o json | jq .items[0].metadata.name| tr -d \")

echo $POD_NAME

kubectl exec -ti $POD_NAME -- nslookup kubernetes

You can see that the service names are getting resolved here.

Server:    100.65.0.10

Address 1: 100.65.0.10 kube-dns.kube-system.svc.cluster.local

Name:      kubernetes

Address 1: 100.65.0.1 kubernetes.default.svc.cluster.local

Resolving external names

[root@kuben1 ~]# kubectl exec -ti $POD_NAME -- nslookup google.com

Server:    100.65.0.10

Address 1: 100.65.0.10 kube-dns.kube-system.svc.cluster.local

Name:      google.com

Address 1: 2404:6800:4005:808::200e hkg12s13-in-x0e.1e100.net

Address 2: 216.58.203.46 hkg12s10-in-f46.1e100.net

[root@kuben1 ~]#

Other relevant links for this documentation.

You can click on any of the link to view them.

The Main Document - Kubernetes 1.10.0 with 3 Master and Slave nodes and SSL on CentOS7

KVM Host and Guest Preprations

SSL Certificate Generations

Configure simple external HAPROXY

Configuring ETCD with SSL on the Master servers

Creation of the POD Network information in ETCD for flanneld

Install and Configure the Master Service on the Kubernetes Master servers

Installation and Configuration of the Kubernetes Slaves

Installation and testing of kube-dns

Configure the masters not to run kubernetes scheduled PODs