Preparing a CentOS node for AE5

vmware-ae5prep.sh

#!/usr/bin/env bash

set -eux

OS="$(gawk -F= '/^NAME/{print $2}' /etc/os-release | sed 's/"//g')"

echo "Detected ${OS} Distro"


if [[ "$OS" =~ ^(CentOS\ Linux|RedHat|Ubuntu)$ ]]; then
	echo "Enabling Modules"
	for i in overlay br_netfilter ebtable_filter ebtables iptable_nat iptable_filter; do echo "$i" | sudo tee /etc/modules-load.d/$i.conf > /dev/null; done
	for i in overlay br_netfilter ebtable_filter ebtables iptable_nat iptable_filter; do sudo modprobe $i; done
	lsmod | grep 'overlay\|br_netfilter\|ebtables\|ebtable_filter'
fi

if [[ "$OS" =~ ^(CentOS\ Linux|RedHat)$ ]]; then
	if [[ `cut -d ' ' -f 4 /etc/redhat-release | cut -d '.' -f 2` == "2" ]]; then
	    echo "Centos 7.2 detected -- loading bridge module"
	    sudo modprobe bridge
	    sudo sysctl -w net.bridge.bridge-nf-call-iptables=1
	fi

echo "Disabling SELinux"
	sudo setenforce 0
	sudo sed -i -- 's/SELINUX\=enforcing/SELINUX\=disabled/g' /etc/selinux/config
	
echo "Modifying Kernel Parameters"
	sudo sed -i -- 's/net\.bridge\.bridge-nf-call-ip6tables\ \=\ 0/net\.bridge\.bridge-nf-call-ip6tables\ \=\ 1/g' /usr/lib/sysctl.d/00-system.conf
	echo 'net.ipv4.ip_forward = 1' | sudo tee --append /usr/lib/sysctl.d/00-system.conf > /dev/null
	sudo sysctl -w net.bridge.bridge-nf-call-ip6tables=1
	sudo sysctl -w net.ipv4.ip_forward=1
	sudo sysctl -w fs.inotify.max_user_watches=1048576
	sudo sysctl -w fs.may_detach_mounts=1 # https://gravitational.com/docs/faq/#kubernetes-pods-stuck-in-terminating-state
	sudo bash -c "echo 'fs.may_detach_mounts = 1' >> /etc/sysctl.d/10-may_detach_mounts.conf"
	sudo bash -c "echo 'net.bridge.bridge-nf-call-iptables=1' >> /etc/sysctl.d/99-bridge.conf"
	sudo bash -c "echo 'net.bridge.bridge-nf-call-ip6tables=1' >> /etc/sysctl.d/99-bridge.conf"
	sudo bash -c "echo 'fs.inotify.max_user_watches=1048576' >> /etc/sysctl.d/99-watches.conf"
	sudo bash -c "echo 'net.ipv4.ip_forward=1' >> /etc/sysctl.d/99-net.conf"
	#MINOR_VERSION=`cat /etc/redhat-release | cut -d" " -f4  | cut -d "." -f2`

fi

if [[ "$OS" =~ ^(SLES)$ ]];
	then
    sudo sysctl -w fs.may_detach_mounts=1
	echo "Enabling more threads"
	echo 'DefaultTasksMax=infinity' | sudo tee --append /etc/systemd/system.conf > /dev/null
fi