# (Optional) fix vi bug in some versions of Mobaxterm (changes first letter of edited file after opening to "g")
vi ~/.vimrc  ==> repeat for root/ubuntu and any other user which will edit files.
# Add the following 2 lines.
syntax on
set background=dark



# Add hostname of kubernetes nodes(master and workers) to /etc/hosts
sudo vi /etc/hosts
# <IP address> <hostname>

# Turn off firewall and allow all incoming HTTP connections through IPTABLES
sudo ufw disable
sudo iptables -I INPUT -j ACCEPT

# Fix server timezone and select your timezone.
sudo dpkg-reconfigure tzdata


# (Optional) create a bash history file as the Ubuntu user so that it does not accidently get created as the root user.  
touch ~/.bash_history  

# (Optional) turn on ssh password authentication and give ubuntu user a password  if you do not like using ssh keys. 
# Set the "PasswordAuthentication yes" in the /etc/ssh/sshd_config file and then set the ubuntu password
sudo vi /etc/ssh/sshd_config;sudo systemctl restart sshd;sudo passwd ubuntu;

# Update the VM with the lates core packages  
sudo apt clean
sudo apt update
sudo apt -y full-upgrade
sudo reboot

# Setup ntp on your image if needed.  It is important that all the VM's clocks are in synch or it will cause problems joining kubernetes nodes to the kubernetes cluster
sudo apt install ntp
sudo apt install ntpdate 

# It is recommended to add local ntp-hostname or ntp server's IP address to the ntp.conf 
# Sync up your vm clock with that of your ntp server. The best choice for the ntp server is one which is different form Kubernetes VMs... a solid machine. Make sure you can ping it!
# A service restart would be needed to synch the time up. You can run them from command line for immediate change.


sudo vi /etc/ntp.conf
# Append the following lines to /etc/ntp.conf, to make them permanent.

date 
sudo service ntp stop
sudo ntpdate -s <ntp-hostname | ntp server's IP address>  ==>e.g.: sudo ntpdate -s 10.247.5.11
sudo service ntp start
date


# Some of the clustering scripts (switch_voting.sh and sdnc_cluster.sh) require JSON parsing, so install jq on th masters only
sudo apt install -y jq

# 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