#!/bin/bash
# kubeadm installation instructions as on
# https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/

if [ $(id -u) != 0 ]; then
  echo "Please run as root or use sudo."
  exit 1
fi

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=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF

# Set SELinux in permissive mode (effectively disabling it)
setenforce 0
sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config

# disable swap (assuming that the name is /dev/centos*/swap)
for device in $(sed -e 's/#.*//' /etc/fstab | awk '$2 == "swap" { print $1 }' | grep ^/dev/); do
    swapoff $device
    sed -i -e "s,$device,#$device," /etc/fstab
done

yum install -y kubelet kubeadm kubectl --disableexcludes=kubernetes

systemctl enable --now kubelet

# Set iptables bridging
cat <<EOF >  /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system