System Preparation for Kubernetes Nodes

System Preparation

Note

The provision-*.yaml playbooks run the base role, which disables swap, loads kernel modules, writes sysctl and inotify settings, and installs base packages. Use this only if you are doing a manual setup.

Disable Swap (Permanently)

Kubernetes requires swap to be disabled. If swap re-enables after reboot, kubelet will fail to start.

sudo swapoff -a
sudo sed -i '/\sswap\s/ s/^/#/' /etc/fstab
cat /etc/fstab | grep swap
free -h

Load Kernel Modules

cat <<EOF | sudo tee /etc/modules-load.d/k8s.conf
overlay
br_netfilter
EOF

sudo modprobe overlay
sudo modprobe br_netfilter

Configure Sysctl

cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-iptables  = 1
net.bridge.bridge-nf-call-ip6tables = 1
net.ipv4.ip_forward                 = 1
EOF

sudo sysctl --system

Increase Inotify Limits

Note

Many containers (Jellyfin, Longhorn, etc.) require higher inotify limits. Without this, containers crash with “too many open files” errors.

sudo sysctl -w fs.inotify.max_user_instances=512
sudo sysctl -w fs.inotify.max_user_watches=524288
echo "fs.inotify.max_user_instances=512" | sudo tee /etc/sysctl.d/99-inotify.conf
echo "fs.inotify.max_user_watches=524288" | sudo tee -a /etc/sysctl.d/99-inotify.conf