Install kubernetes on Debian based and Red Hat based systems

kubenetes_install.sh

# setting selinux to permissive/disabled
SELINUX_STATE=$(getenforce)
if [ "$SELINUX_STATE" == "Enforcing" ]; then
    setenforce 0
    sed -i --follow-symlinks 's/SELINUX=enforcing/SELINUX=disabled/g'\
        /etc/sysconfig/selinux
fi

# enabling the br_netfilter module for cluster communication
modprobe br_netfilter
echo '1' > /proc/sys/net/bridge/bridge-nf-call-iptables

# Allowing iptalbes to see the bridged traffic correctly
cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF

# Disable swap permanently
swapoff -a 
sed '/^#/! {/swap/ s/^/#/}' -i /etc/fstab


# Install Docker prerequisite and docker
source /etc/os-release
distro=$ID
if [ "$distro" == "ubuntu" ]; then
    #docker prerequisite
    sudo apt-get update 
    sudo apt-get install -y \
    ca-certificates \
    apt-transport-https \
    curl \
    gnupg \
    lsb-release

    curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg
    echo \
    "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu \
    $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

    #docker
    sudo apt-get update
    sudo apt-get install -y docker-ce docker-ce-cli containerd.io

    # kubernetes google publick keyring
    sudo curl -fsSLo /usr/share/keyrings/kubernetes-archive-keyring.gpg https://packages.cloud.google.com/apt/doc/apt-key.gpg
    # add repo
    echo "deb [signed-by=/usr/share/keyrings/kubernetes-archive-keyring.gpg] https://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee /etc/apt/sources.list.d/kubernetes.list

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

    systemctl daemon-reload
    systemctl enable docker
    systemctl restart docker
    #systemctl status docker
    docker info | grep -i cgroup

    # Install pin docker version
    sudo apt-get update
    sudo apt-get install -y kubelet kubeadm kubectl
    sudo apt-mark hold kubelet kubeadm kubectl
    #sudo systemctl enable --now kubelet

elif [ "$distro" == "centos" ]; then
    sudo yum install -y yum-utils
    sudo yum-config-manager \
    --add-repo \
    https://download.docker.com/linux/centos/docker-ce.repo

    sudo yum install -y docker-ce docker-ce-cli containerd.io

    # docker cgroup driver
    sed -i '/^ExecStart/ s/$/ --exec-opt native.cgroupdriver=systemd/' /usr/lib/systemd/system/docker.service 
    systemctl daemon-reload
    systemctl enable docker --now 
    systemctl status docker 2>&1
    docker info | grep -i cgroup


    # Add kubernetes repo
    cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg
      https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF

    # install and enable kubernetes
    sudo yum install -y kubelet kubeadm kubectl --disableexcludes=kubernetes
    sudo systemctl enable --now kubelet
    
fi