Proxmox_Helper_scripts/misc/add-tailscale-lxc.sh

#!/usr/bin/env bash

# Copyright (c) 2021-2023 tteck
# Author: tteck (tteckster)
# License: MIT
# https://github.com/tteck/Proxmox/raw/main/LICENSE

function header_info {
cat <<"EOF"
  ______      _ __                __        
 /_  __/___ _(_) /_____________ _/ /__      
  / / / __ `/ / / ___/ ___/ __ `/ / _ \     
 / / / /_/ / / (__  ) /__/ /_/ / /  __/     
/_/  \__,_/_/_/____/\___/\__,_/_/\___/      
                                            
EOF
}
clear
header_info
while true; do
  read -p "This will add Tailscale to an existing LXC Container ONLY. Proceed(y/n)?" yn
  case $yn in
  [Yy]*) break ;;
  [Nn]*) exit ;;
  *) echo "Please answer yes or no." ;;
  esac
done

set -o errexit
set -o errtrace
set -o nounset
set -o pipefail
shopt -s expand_aliases
alias die='EXIT=$? LINE=$LINENO error_exit'
trap die ERR

function error_exit() {
  trap - ERR
  local reason="Unknown failure occured."
  local msg="${1:-$reason}"
  local flag="\e[1;31m‼ ERROR\e[0m $EXIT@$LINE"
  echo -e "$flag $msg" 1>&2
  exit $EXIT
}
function msg() {
  local TEXT="$1"
  echo -e "$TEXT"
}

NODE=$(hostname)
while read -r line; do
  TAG=$(echo "$line" | awk '{print $1}')
  ITEM=$(echo "$line" | awk '{print substr($0,36)}')
  OFFSET=2
  if [[ $((${#ITEM} + $OFFSET)) -gt ${MSG_MAX_LENGTH:-} ]]; then
    MSG_MAX_LENGTH=$((${#ITEM} + $OFFSET))
  fi
  CTID_MENU+=("$TAG" "$ITEM " "OFF")
done < <(pct list | awk 'NR>1')

while [ -z "${CTID:+x}" ]; do
  CTID=$(whiptail --title "Containers on $NODE" --radiolist \
    "\nSelect a container to add Tailscale to:\n" \
    16 $(($MSG_MAX_LENGTH + 23)) 6 \
    "${CTID_MENU[@]}" 3>&1 1>&2 2>&3) || exit
done

CTID_CONFIG_PATH=/etc/pve/lxc/${CTID}.conf
cat <<EOF >>$CTID_CONFIG_PATH
lxc.cgroup2.devices.allow: c 10:200 rwm
lxc.mount.entry: /dev/net/tun dev/net/tun none bind,create=file
EOF

msg "Installing Tailscale..."
lxc-attach -n $CTID -- bash -c "$(curl -fsSL https://tailscale.com/install.sh)" &>/dev/null || exit
msg "Installed Tailscale"
sleep 2
msg "\e[1;32m ✔ Completed Successfully!\e[0m"
msg "\e[1;31m Reboot ${CTID} LXC to apply the changes, then run tailscale up in the LXC console\e[0m"