Bootstrapping the Cluster.txt

# CHAPTER 2.5 - Bootstrapping the Cluster
# https://learn.acloud.guru/course/2e0bad96-a602-4c91-9da2-e757d32abb8f/learn/56bea242-4b92-4bcb-ad80-f974467c8d7a/e896865d-af4d-43ec-92f9-a3c1b14433fc/watch

# On Kube Master, Kube Node 1 and Kube Node 2, stop and disable ufw:

sudo systemctl stop ufw
sudo ufw disable

# On the Kube Master node, initialize the cluster:

sudo kubeadm init --pod-network-cidr 192.168.0.0/16

# Set kubectl access:

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

# The kubeadm init command should output a kubeadm join command containing a token and hash. Copy that command and run it with sudo on both worker nodes. It should look something like this:

sudo kubeadm join $some_ip:6443 --token $some_token --discovery-token-ca-cert-hash $some_hash

# Use can print the full 'kubeadm join' flag needed to join the cluster with the following command:

kubeadm token create --print-join-command

# Run the kubeadm join command on your Kube Node 1 and Kube Node 2 servers:

sudo kubeadm join <IP_ADDRESS> --token <TOKEN> --discovery-token-ca-cert-hash sha256:<HASH>

# From your Kube Master node, verify that all nodes have successfully joined the cluster:

kubectl get nodes

# You should see all three of your nodes listed. It should look something like this:

NAME                           STATUS     ROLES           AGE     VERSION
155f1d1c831c.mylabserver.com   NotReady   control-plane   2m21s   v1.30.3
155f1d1c832c.mylabserver.com   NotReady   <none>          37s     v1.30.3
155f1d1c833c.mylabserver.com   NotReady   <none>          12s     v1.30.3

# Note: The nodes are expected to have a STATUS of NotReady at this point