Bash script to initialize oracle cloud VM for running Kubernetes

init-vm.sh

#!/usr/bin/env bash

set -e

# Disable swap
sudo swapoff -a
sudo sed -i '/swap/d' /etc/fstab

# Load necessary kernel modules
sudo modprobe overlay
sudo modprobe br_netfilter

# Set up required sysctl params for Kubernetes
sudo tee /etc/sysctl.d/k8s.conf<<EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
EOF
##  --system flag loads kernel modules immediately
sudo sysctl --system

# Install containerd
sudo yum-config-manager --add-repo https://download.docker.com/linux/rhel/docker-ce.repo
sudo yum install  containerd.io -y

# Update cgroup driver in containerd
cp /etc/containerd/config.toml /etc/containerd/config.toml.bak
sudo rm /etc/containerd/config.toml

sudo tee /etc/containerd/config.toml <<EOF
[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc]
  [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options]
    SystemdCgroup = true
EOF

sudo systemctl restart containerd
sudo systemctl enable containerd

# Set SELinux in disabled mode (effectively disabling it)

sudo setenforce 0 # this temporaily disables selinux lost after reboot.
sudo sed -i 's/^SELINUX=enforcing$/SELINUX=disabled/' /etc/selinux/config

# Install Kubernetes components
# This overwrites any existing configuration in /etc/yum.repos.d/kubernetes.repo
sudo tee /etc/yum.repos.d/kubernetes.repo<<EOF
[kubernetes]
name=Kubernetes
baseurl=https://pkgs.k8s.io/core:/stable:/v1.31/rpm/
enabled=1
gpgcheck=1
gpgkey=https://pkgs.k8s.io/core:/stable:/v1.31/rpm/repodata/repomd.xml.key
exclude=kubelet kubeadm kubectl cri-tools kubernetes-cni
EOF

sudo firewall-cmd --zone=public --permanent --add-port=10250/tcp
sudo firewall-cmd --zone=public --permanent --add-port=6443/tcp
sudo firewall-cmd --zone=public --permanent --add-port=10249/tcp
sudo firewall-cmd --zone=public --permanent --add-port=80/tcp
sudo firewall-cmd --zone=public --permanent --add-port=443/tcp
sudo firewall-cmd --reload

sudo yum install -y kubelet kubeadm kubectl --disableexcludes=kubernetes
sudo systemctl enable kubelet && sudo systemctl start kubelet


sudo systemctl status kubelet >&1

sudo systemctl status containerd

exit 0