This script is meant to setup Kubernetes Environment on Ubuntu / Debian supported paltforms

KubernetesSetupUbuntu.sh

#!/bin/bash
# Maintainer : Mansur Ul Hasan
# EMail : [email protected]
# LinkedIn : https://www.linkedin.com/in/mansurulhasan/
# Youtube : https://www.youtube.com/user/mansur7820/

# This script is meant to setup Kubernetes Environment on Ubuntu / Debian supported paltforms 
# We have try to cover all the required tools modules which needed by modern kubernetes 
# Disclaimer : 
# This script is well tested on ubuntu 18 and 16 
# before using this script you must ensure what you are doing this script will change some kernel 
# parameters as well please double check that part to match your environment requirements 

# How to use this script
# Download or clone script your server and run with given options
# Script has various options to invidiual functions accroding to requirements 
# Here are some options with their definations 
#  MacBook-Pro-de-user:~ mulhasan$ sh KubernetesSetupUbuntu.sh --youroption
# --master	Use this option when Kubenrnetes master need to setup on machine
# --node	Use this option when slave of kubenrnetes need to install
# --docker	This option can be used when only docker=ce 
# --crio	CRI-O (Container Runtime Interface) is optional tool for kubernetes 
# --kubebin	This option enables you to install kubelet kubeadm kubectl kube-cni
# --containerd	This Option enables to install containerd daemon

InstallDocker () {

# Install Docker CE
## Set up the repository:
### Install packages to allow apt to use a repository over HTTPS
	apt-get update && apt-get install apt-transport-https ca-certificates curl software-properties-common

### Add Docker’s official GPG key
	curl -fsSL https://download.docker.com/linux/ubuntu/gpg | apt-key add -

### Add Docker apt repository.
	add-apt-repository \
  	"deb [arch=amd64] https://download.docker.com/linux/ubuntu \
  	$(lsb_release -cs) \
  	stable"

## Install Docker CE.
	apt-get update && apt-get install docker-ce=18.06.2~ce~3-0~ubuntu

# Setup daemon.
cat > /etc/docker/daemon.json <<EOF
{
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  },
  "storage-driver": "overlay2"
}
EOF

	mkdir -p /etc/systemd/system/docker.service.d

# Restart docker.
	systemctl daemon-reload
	systemctl restart docker

}


InstallCRIO () {

#CRI-O is meant to provide an integration path between OCI conformant runtimes and the kubelet. Specifically, it implements the Kubelet Container Runtime Interface (CRI) using OCI conformant runtimes. The scope of CRI-O is tied to the scope of the CRI.

#At a high level, we expect the scope of CRI-O to be restricted to the following functionalities:

#    Support multiple image formats including the existing Docker image format
#    Support for multiple means to download images including trust & image verification
#    Container image management (managing image layers, overlay filesystems, etc)
#    Container process lifecycle management
#    Monitoring and logging required to satisfy the CRI
#    Resource isolation as required by the CRI

# Probing required modules 

	modprobe overlay
	modprobe br_netfilter

# Setup required sysctl params, these persist across reboots.
cat > /etc/sysctl.d/99-kubernetes-cri.conf <<EOF
net.bridge.bridge-nf-call-iptables  = 1
net.ipv4.ip_forward                 = 1
net.bridge.bridge-nf-call-ip6tables = 1
EOF

# Reloading Kernel parameters
	sysctl --system

# Install prerequisites
	apt-get update
	apt-get install software-properties-common

	add-apt-repository ppa:projectatomic/ppa
	apt-get update

# Install CRI-O
	apt-get install cri-o-1.11

# Restart CRI-O 
systemctl start crio

# Refer to the CRI-O installation guide for more information.
# https://github.com/kubernetes-sigs/cri-o#getting-started

}

InstallContainerd () { 

#This section contains the necessary steps to use containerd as CRI runtime.
#Use the following commands to install Containerd on your system

modprobe overlay
modprobe br_netfilter

# Setup required sysctl params, these persist across reboots.
#cat > /etc/sysctl.d/99-kubernetes-cri.conf <<EOF
#net.bridge.bridge-nf-call-iptables  = 1
#net.ipv4.ip_forward                 = 1
#net.bridge.bridge-nf-call-ip6tables = 1
#EOF

#sysctl --system
# Install containerd
## Set up the repository
### Install packages to allow apt to use a repository over HTTPS
	apt-get update && apt-get install -y apt-transport-https ca-certificates curl software-properties-common

### Add Docker’s official GPG key
	curl -fsSL https://download.docker.com/linux/ubuntu/gpg | apt-key add -

### Add Docker apt repository.
	add-apt-repository \
    	"deb [arch=amd64] https://download.docker.com/linux/ubuntu \
    	$(lsb_release -cs) \
    	stable"

## Install containerd
	apt-get update && apt-get install -y containerd.io

# Configure containerd
	mkdir -p /etc/containerd
	containerd config default > /etc/containerd/config.toml

# Restart containerd
	systemctl restart containerd

# To use the systemd cgroup driver, set plugins.cri.systemd_cgroup = true in /etc/containerd/config.toml. When using kubeadm, manually configure 
# the cgroup driver for kubelet as well.

	sed -i 's/plugins.cri.systemd_cgroup = false/plugins.cri.systemd_cgroup = true/g' /etc/containerd/config.toml 

# Restart containerd service 
	systemctl restart containerd

}

SetupKubernetesBin () {
# This function will install kubectl kubelet kubeadm kubernetes-cni binaries 
# This function may need to execute on all nodes across cluster 

# Add Kubernetes repository 

	apt-get update; apt-get install -y apt-transport-https; 
	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 -a /etc/apt/sources.list.d/kubernetes.list
	apt-get update 

# Install Kubernetes components 
	sudo apt-get update
	sudo apt-get install -y kubelet kubeadm kubernetes-cni
}

InitMaster () {
# This Function will setup master and this function only need to run on master
# At first we will aquire required infromation to setup master 
# like IP Address Interface name etc 

	echo "Enter interface name which need to use to connect node's network
	In our case this is our local network and we named it as eth0 "
	sleep 10
	echo " "
	echo " "
	read -p "Enter Interface Name : " MasterInterface
	MasterIP=`ifconfig $MasterInterface |grep "inet addr" |cut -d : -f2|awk '{print $1}'`

# Now we have all the required information to setup master 

	kubeadm init --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=$MasterIP --cri-socket=/var/run/dockershim.sock
}

SettingEnv () {
# Setting up Environment to access kubernetes cluster from CLI 
	echo "\e[1;31mWe are about to setup User Environment\e[0m"
	sleep 30
	
	cd $HOME
	whoami
	cp /etc/kubernetes/admin.conf $HOME/
	chown $(id -u):$(id -g) $HOME/admin.conf
	export KUBECONFIG=$HOME/admin.conf
	echo "export KUBECONFIG=/etc/kubernetes/admin.conf" | tee -a ~/.bashrc
	source ~/.bashrc
}
SettingNetwork () {
# Our cluster is setup now next thing we need to setup networking module 
	echo "\e[1;31mNow Sit tight networking module is setting up\e[0m"
	kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
	
# Tainting Nodes
	kubectl taint nodes --all dedicated-	
}

SetupNode () { 
# If Nodes need to setup execut this function this will install all required packages for nodes
	
	InstallDocker
	InstallCRIO
	InstallContainerd
	SetupKubernetesBin
}
		
SetupMaster () {
# If master need to setup this function will setup master 

	InstallDocker
        InstallCRIO
        InstallContainerd
        SetupKubernetesBin
	InitMaster
	SettingEnv
	SettingNetwork
}

case $1 in 
--master) 
	SetupMaster
;;
--node)
	SetupNode
;;
--docker)
	InstallDocker
;;
--crio)
	InstallCRIO
;;
--kubebin)
	SetupKubernetesBin
;;
--containerd)
	InstallContainerd
;;
esac