Kuberbetes (K8) nginx webpage

There are 3 readme.md files (steps) in this repo. This one shows how to install. The second step configures the cluster. The third step sets up monitoring with Lens.

Check out the kubernetes_glossary.pdf for reference on any terms

Prerequisites

1. Three servers running an Ubuntu OS I used a VM and 2 physical PC's reimaged
2. Minimum 2 GB RAM and 2 Core CPUs on each node
3. A root password configured on each server

The following steps will be done on all servers.

Update System Packages

First, update the system packages with the following command:

sudo apt-get update

Step 1 – Disable Swap and Enable IP Forwarding

First, turn swap off:

swapoff -a

Edit permanently

nano /etc/fstab

Comment out #/swapfile

Next, edit the /etc/sysctl.conf file to enable the IP forwarding:

nano /etc/sysctl.conf

Uncomment this line below "net.ipv4.ip_forward = 1"

Apply settings

sysctl -p

Step 2: Install Docker

Kubernetes requires Docker to be installed on the system. Install Docker with the following commands:

sudo apt-get install apt-transport-https ca-certificates curl software-properties-common
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
sudo apt-get install docker-ce -y

Step 3: Install Kubernetes

Now, install Kubernetes with the following commands:

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
echo "deb http://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee /etc/apt/sources.list.d/kubernetes.list
sudo apt-get update -y
sudo apt-get install kubelet kubeadm kubectl -y

Next, you will need to update the cgroupdriver

nano /etc/docker/daemon.json

Add the following lines:

{ "exec-opts": ["native.cgroupdriver=systemd"],
"log-driver": "json-file",
"log-opts":
{ "max-size": "100m" },
"storage-driver": "overlay2"
}

Save and reload:

systemctl daemon-reload
systemctl restart docker
systemctl enable docker

On the main server only run the following commands:

Initialize Kubernetes

sudo kubeadm init --pod-network-cidr=10.69.0.0/16

VERY IMPORTANT

Copy the cubeadm join full command and save for later

Configure Kubernetes

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

Deploy Pod Network

kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

Go back to your worker nodes (not the main):

Step 4 – Join Worker Nodes to the Kubernetes Cluster

Your cubeadm join command should look like this:

kubeadm join 192.168.1.1:6989 --token blahhhxx5t2f66cpqz8e --discovery-token-ca-cert-hash shaxxxxxxxxxxxxxxxxxxxx

Go back to main server and validate

Step 5: Verify Installation

kubectl get pods --all-namespaces