ubuntu_install_k3s.sh

install_k3s.sh

#!/bin/bash
if [[ $EUID -ne 0 ]]; then
  echo "$0 is not running as root. Try using sudo."
  exit 2
fi
set -e

DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
OFFLINE=0
MAX_POD_CNT=0
DATA_PATH=""
CLUSTER_MODE=0
AGENT_MODE=0
SERVER_TOKEN=""
SERVER_IP=""
# NOTE: k3s version must match rancher version!!!
K3S_VERSION="v1.23.16+k3s1"
export DEBIAN_FRONTEND=noninteractive

if [ -f "$DIR/do_install.sh" ] && [ -f "$DIR/k3s" ] && [ -f "$DIR/k3s-airgap-images-amd64.tar.gz" ]; then
  OFFLINE=1
fi

help() {
  echo "install script for k3s, only works for Ubuntu"
  echo "Usage:"
  echo "  k3s_install.sh [-c] [-a] [-s server_url] [-t server_token] [-p max_pod_cnt] [-d data_path]"
  echo "  -c: install server as cluster mode, use embedded etcd instead of sqlite. Use it for multi servers, but not one server and multi agents. "
  echo "  -a: install k3s as agent. Use it with -t <server token> and -s <server url>"
  echo "  -t: token, for server or agent join cluster"
  echo "  -s: server ip"
  echo "  -p: max pod count, default is 110"
  echo "  -d: data path, default is /var/lib/rancher/k3s"
  echo "  -o: force online mode"
  exit 0
}

while getopts 's:t:p:d:caoh' OPT; do
  case $OPT in
  c) CLUSTER_MODE=1 ;;
  a) AGENT_MODE=1 ;;
  t) SERVER_TOKEN="$OPTARG" ;;
  s) SERVER_IP="$OPTARG" ;;
  p) MAX_POD_CNT="$OPTARG" ;;
  d) DATA_PATH="$OPTARG" ;;
  o) OFFLINE=0 ;;
  h) help ;;
  ?) help ;;
  esac
done

if [ $OFFLINE -eq 1 ]; then
  echo "Detect offline files, enable offline mode. You can still use -o to disable offline mode."
  chmod a+x "$DIR/k3s"
  K3S_VERSION=$("$DIR"/k3s --version | head -1 | awk '{print $3}')
fi
echo "To install k3s version is $K3S_VERSION"

# Check parameters
if [ $AGENT_MODE -eq 1 ] && { [ -z "$SERVER_IP" ] || [ -z "$SERVER_TOKEN" ]; }; then
  echo "miss server_ip or server_token for agent mode"
  exit 1
fi
if [ -n "$SERVER_IP" ] && [ -n "$SERVER_TOKEN" ] && [ $AGENT_MODE -eq 0 ]; then
  echo "Cluster mode enabled"
  CLUSTER_MODE=1
fi

# upgrade kernel
if [ $OFFLINE -eq 0 ]; then
  apt update && apt upgrade -y
  apt install -y curl
fi
# Check if DHCP is being used
# Retrieve the network interface name
iface=$(ip route | awk '/default/ { print $5 }' | head -1)

if [[ $(ip -o -4 addr show dev "$iface") == *"dynamic"* ]]; then
  # Retrieve the current IP address and gateway settings from DHCP
  ip=$(ip addr show "$iface" | awk '/inet / {print $2}' | cut -f1 -d'/')
  gateway=$(ip route | awk '/default/ {print $3}' | head -1)
  echo "$iface IP address set to static: $ip, gateway:$gateway"
  sudo netplan generate
  sudo bash -c "cat > /etc/netplan/01-netcfg.yaml" <<EOF
network:
  version: 2
  renderer: networkd
  ethernets:
    $iface:
      dhcp4: no
      addresses: [$ip/24]
      gateway4: $gateway
      nameservers:
        addresses: [114.114.114.114,180.76.76.76]
EOF
  sudo netplan apply
else
  # If not using DHCP, do nothing
  echo "IP address is already static, nothing to change..."
fi

# install if k3s not exist or version not match
if [ ! -f "/usr/local/bin/k3s" ] || [[ $(k3s --version | head -1 | awk '{print $3}') != "$K3S_VERSION" ]]; then
  fresh_install=1
  if [ -f "/usr/local/bin/k3s" ]; then
    fresh_install=0
  fi
  opts="K3S_KUBECONFIG_MODE=\"644\""
  cmd=""
  server_url="https://$SERVER_IP:6443"
  if [ $AGENT_MODE -eq 1 ]; then
    echo "install k3s as agent, server url is $server_url"
    opts="$opts K3S_URL=$server_url K3S_TOKEN=$SERVER_TOKEN"
  else
    if [ $CLUSTER_MODE -eq 1 ]; then
      if [ -z "$SERVER_TOKEN" ] || [ -z "$SERVER_IP" ]; then
        cmd="server --cluster-init"
      else
        opts="$opts K3S_TOKEN=$SERVER_TOKEN"
        cmd="server --server $server_url"
      fi
    fi
  fi
  # firewall settings
  if [[ $(ufw status) == *"inactive"* ]]; then
    echo "firewall disabled, skip setting..."
  else
    echo "firewall enabled, set ufw..."
    sudo ufw allow 2379/tcp
    sudo ufw allow 2380/tcp
    sudo ufw allow 6443/tcp
    sudo ufw allow 8472/udp
    sudo ufw allow 10250/tcp
    sudo ufw allow 51820/udp
    sudo ufw allow 51821/udp
  fi
  # set to `--kube-proxy-arg=proxy-mode=ipvs` if you want ipvs mode
  exec_opts=""
  if [ "$MAX_POD_CNT" -gt 0 ]; then
    exec_opts="$exec_opts --kubelet-arg=max-pods=$MAX_POD_CNT"
  fi
  if [ -n "$DATA_PATH" ]; then
    exec_opts="$exec_opts --data-dir=$DATA_PATH"
  fi
  if [ -n "$exec_opts" ]; then
    exec_opts=$(echo "$exec_opts" | xargs)
    opts="$opts INSTALL_K3S_EXEC='$exec_opts'"
  fi
  if [ $OFFLINE -eq 0 ]; then
    echo "install k3s online..."
    opts="$opts INSTALL_K3S_MIRROR=cn INSTALL_K3S_VERSION=$K3S_VERSION"
    cmd="curl -sfL https://rancher-mirror.rancher.cn/k3s/k3s-install.sh | $opts sh -s - $cmd"
  else
    echo "install k3s offline..."
    gunzip -c "$DIR"/k3s-airgap-images-amd64.tar.gz >"$DIR"/k3s-airgap-images-amd64.tar
    mkdir -p /var/lib/rancher/k3s/agent/images/
    mv "$DIR"/k3s-airgap-images-amd64.tar /var/lib/rancher/k3s/agent/images/
    cp k3s /usr/local/bin
    chmod +x /usr/local/bin/k3s
    chmod +x "$DIR"/do_install.sh
    opts="$opts INSTALL_K3S_SKIP_DOWNLOAD=true"
    cmd="$opts $DIR/do_install.sh $cmd"
  fi
  echo "$cmd"
  eval "$cmd"
  if [ -z "$SERVER_TOKEN" ]; then
    echo ""
    echo "server token is:"
    cat /var/lib/rancher/k3s/server/token
    echo "server ip is:"
    ip addr show "$iface" | awk '/inet / {print $2}' | cut -f1 -d'/'
  fi
  if [ $fresh_install -eq 0 ]; then
    echo "restart k3s for upgrade..."
    systemctl restart k3s
  fi
  echo ""
else
  echo "skip k3s install..."
fi

if [ $AGENT_MODE -eq 0 ]; then
  echo "restart every 9 month for certificate rotate in server node"
  grep 'systemctl restart k3s' /etc/crontab || echo '0 2 1 */9 * systemctl restart k3s >/dev/null 2>&1' >>/etc/crontab
  echo ""
  echo "=========================NOTE================================"
  echo "Please register k3s to rancher manually."
  echo "Then run 'kubectl get pods -A' to watch pod status"
  echo "After all the pods getting ready, you should see k3s active in rancher"
fi