htzner-k3s dedicated server as agent

script.sh

touch /etc/initialized

HOSTNAME=$(hostname -f)
PUBLIC_IP=$(hostname -I | awk '{print $1}')

if [ "true" = "true" ]; then
  echo "Using private network " >/var/log/hetzner-k3s.log
  SUBNET="10.0.1.0/24"
  MAX_ATTEMPTS=30
  DELAY=10
  UP="false"

  for i in $(seq 1 $MAX_ATTEMPTS); do
    NETWORK_INTERFACE=$(
      ip -o link show |
        grep -E 'mtu 1400|mtu 1450' |
        awk -F': ' '{print $2}' |
        sed 's/@.*//' |
        grep -Ev 'cilium|br|flannel|docker|veth' |
        xargs -I {} bash -c 'ethtool {} &>/dev/null && echo {}' |
        head -n1
    )

    if [ ! -z "$NETWORK_INTERFACE" ]; then
      echo "Private network IP in subnet $SUBNET is up" 2>&1 | tee -a /var/log/hetzner-k3s.log
      UP="true"
      break
    fi
    echo "Waiting for private network IP in subnet $SUBNET to be available... (Attempt $i/$MAX_ATTEMPTS)" 2>&1 | tee -a /var/log/hetzner-k3s.log
    sleep $DELAY
  done

  if [ "$UP" = "false" ]; then
    echo "Timeout waiting for private network IP in subnet $SUBNET" 2>&1 | tee -a /var/log/hetzner-k3s.log
  fi

  PRIVATE_IP=$(
    ip -4 -o addr show dev "$NETWORK_INTERFACE" |
      awk '{print $4}' |
      cut -d'/' -f1 |
      head -n1
  )
  FLANNEL_SETTINGS=" --flannel-iface=$NETWORK_INTERFACE "
else
  echo "Using public network " >/var/log/hetzner-k3s.log
  PRIVATE_IP="${PUBLIC_IP}"
  FLANNEL_SETTINGS=" "
fi

mkdir -p /etc/rancher/k3s

cat >/etc/rancher/k3s/registries.yaml <<EOF
mirrors:
  "*":
EOF

curl -sfL https://get.k3s.io | K3S_TOKEN="..." INSTALL_K3S_VERSION="v1.30.8+k3s1" K3S_URL=https://10.0.0.3:6443 INSTALL_K3S_EXEC="agent \
--node-name=$HOSTNAME  --kubelet-arg "cloud-provider=external"  --kubelet-arg "resolv-conf=/etc/k8s-resolv.conf"  \
--node-ip=$PRIVATE_IP \
--node-external-ip=$PUBLIC_IP \
--node-label=instance.hetzner.cloud/provided-by=robot \
--node-label=instance.hetzner.cloud/is-root-server=true \
$FLANNEL_SETTINGS " sh -

echo true >/etc/initialized