Kubernetes

Kubernetes is a portable, extensible, open-source platform for managing containerized workloads and services, that facilitates both declarative configuration and automation. It has a large, rapidly growing ecosystem. Kubernetes services, support, and tools are widely available.

Prerquesties

Master: t2.medium (2 CPUs and 2GB Memory)

Worker Nodes: t2.micro

Install Kubernetes Cluster using kubeadm

Follow this documentation to set up a Kubernetes cluster on Ubuntu 20.04 LTS.

This documentation guides you in setting up a cluster with one master node and one worker node.

Open the below ports on master on worker node

Master node: 6443 32750 10250 4443 443 8080

On Master node and Worker node: 179

On both Kmaster and Kworker

Login as root user

sudo su -

Perform all the commands as root user unless otherwise specified

Disable Firewall

ufw disable

Disable swap

swapoff -a; sed -i '/swap/d' /etc/fstab

Update sysctl settings for Kubernetes networking

cat >>/etc/sysctl.d/kubernetes.conf<<EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system

Install docker engine

{
  apt install -y apt-transport-https ca-certificates curl gnupg-agent software-properties-common
  curl -fsSL https://download.docker.com/linux/ubuntu/gpg | apt-key add -
  add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
  apt update
  apt install -y docker-ce=5:19.03.10~3-0~ubuntu-focal containerd.io
}

Kubernetes Setup

Add Apt repository

{
  curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
  echo "deb https://apt.kubernetes.io/ kubernetes-xenial main" > /etc/apt/sources.list.d/kubernetes.list
}

Install Kubernetes components

apt update && apt install -y kubeadm=1.18.5-00 kubelet=1.18.5-00 kubectl=1.18.5-00

In case you are using LXC containers for Kubernetes nodes Hack required to provision K8s v1.15+ in LXC containers

{
  mknod /dev/kmsg c 1 11
  echo '#!/bin/sh -e' >> /etc/rc.local
  echo 'mknod /dev/kmsg c 1 11' >> /etc/rc.local
  chmod +x /etc/rc.local
}

On kmaster

Initialize Kubernetes Cluster

Update the below command with the ip address of kmaster

kubeadm init --apiserver-advertise-address=172.16.16.100 --pod-network-cidr=192.168.0.0/16  --ignore-preflight-errors=all

Deploy Calico network

kubectl --kubeconfig=/etc/kubernetes/admin.conf create -f https://docs.projectcalico.org/v3.14/manifests/calico.yaml

Cluster join command

kubeadm token create --print-join-command

To be able to run kubectl commands as non-root user If you want to be able to run kubectl commands as non-root user, then as a non-root user perform these

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

On Kworker

Join the cluster

Use the output from kubeadm token create command in previous step from the master server and run here.

Verifying the cluster (On kmaster)

Get Nodes status

kubectl get nodes

Get component status

kubectl get cs

TO Deploy Nginx on cluster

kubectl create deploy nginx --image nginx

On K Master

kubectl get nodes

Ok Now We will going to Deploy Nginx Image for testing Purpose.

kubectl create deploy nginx --image nginx

To Get All the Deployment and pods details execute the commands.

kubectl get all

To Expose the Nginx port

kubectl expose deploy nginx --port 80 --type NodePort

To Check Execute the get svc command

kubectl get svc

Now check the Node public IP in Browser

Thats All Guys...