# On the k8s-master vm setup the kubernetes master node.  
# The "sudo -i" changes user to root.
sudo -i

# There is no kubernetes app running. 
ps -ef | grep -i kube | grep -v grep

# Pick one DNS add-on: either "kube-dns" or "CoreDNS".  If your environment setup is for "Kubernetes federation" or "SDN-C Geographic Redundancy" then use "CoreDNS" addon.
# Note that kubeadm version 1.8.x does not have support for coredns feature gate. 
# Upgrade kubeadm to latest version before running below command:

# With "CoreDNS" addon (recommended)
kubeadm init --feature-gates=CoreDNS=true | tee ~/kubeadm_init.log 

# with kube-dns addon
kubeadm init | tee ~/kubeadm_init.log

# Verify many kubernetes app running (kubelet,  kube-scheduler, etcd, kube-apiserver, kube-proxy, kube-controller-manager)
ps -ef | grep -i kube | grep -v grepkube-controller-managergrep

# The "exit" reverts user back to ubuntu.
exit

sudo kubectl get pods --all-namespaces -o wide
NAMESPACE     NAME                                    READY     STATUS    RESTARTS   AGE       IP               NODE
kube-system   etcd-k8s-master                      1/1       Running   0          1m        10.147.112.140   k8s-master
kube-system   kube-apiserver-k8s-master            1/1       Running   0          1m        10.147.112.140   k8s-master
kube-system   kube-controller-manager-k8s-master   1/1       Running   0          1m        10.147.112.140   k8s-master
kube-system   kube-dns-545bc4bfd4-jcklm            3/3       Running   0          44m       10.32.0.2        k8s-master
kube-system   kube-proxy-lnv7r                     1/1       Running   0          44m       10.147.112.140   k8s-master
kube-system   kube-scheduler-k8s-master            1/1       Running   0          1m        10.147.112.140   k8s-master
kube-system   weave-net-b2hkh                      2/2       Running   0          1m        10.147.112.140   k8s-master


#(There will be 2 coredns pods with different IP addresses, with kubernetes version 1.10.1)

# Verify the AVAIABLE flag for the deployment "kube-dns" or "coredns" will be changed to 1. (2 with kubernetes version 1.10.1)
#For coredns
sudo kubectl get deployment --all-namespaces
NAMESPACE     NAME      DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
kube-system   coredns   2         2         2            2           2m

#For kubedns
sudo kubectl get deployment --all-namespaces
NAMESPACE     NAME       DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
kube-system   kube-dns   1         1         1            1           1h