Tailscale wrapper to quickly change exit node configuration

tailscale-exitnode

#!/bin/bash

# colours 
GREEN='\033[0;32m'
NC='\033[0m'

CONFIG_PATH=~/.config/.tsen

function _usage(){
    echo -e "\nUsage: ${0} [--exit-node <tailscale_node_name>] [--clear | --none]\n"
}

function _critical(){
    echo "[CRIT] $@"
}

function _list(){
    echo -e " Nodes\n-------"
    anode=$(tailscale status | grep '; exit node;' | awk '{print $2}')
    for i in $(tailscale status | grep 'exit node;' | awk '{print $2}'); do
        if [ "${i}" = "${anode}" ]; then
            echo -e "${GREEN}*${i}${NC}"
        else 
            echo "${i}"
        fi 
    done 
}

function _last(){
    # $0 --exit-node $(head -n 1 ${CONFIG_PATH} | cut -d' ' -f1)
    head -n 1 ${CONFIG_PATH} | cut -d' ' -f1
}

POSITIONAL_ARGS=()

while [[ $# -gt 0 ]]; do
    case $1 in
        ls|--list)
            _list
            exit 80
            ;;
        --none|--clear)
            EXIT_NODE_CLEAR="true"
            shift
            ;;
        --exit-node|--node)
            EXIT_NODE="${2}"
            shift
            shift
            ;;
        --last)
            EXIT_NODE="$(_last)"
            shift
            ;;
        *)
            POSITIONAL_ARGS+=("$1") # save positional arg
            shift # past argument
            ;;
    esac
done

# echo "pos args: ${#POSITIONAL_ARGS[@]}"

if [[ -z "${EXIT_NODE}" ]] && [[ -z "${EXIT_NODE_CLEAR}" ]]; then
    _critical "Need to provide something to do..."
    _usage && exit 99
fi

stdout=$(tailscale up --exit-node=${EXIT_NODE}  2>&1)
if echo "${stdout}" | grep "invalid value" &>/dev/null; then 
    _critical "Exit node doesnt exist: ${EXIT_NODE}. Exiting..."
    exit 98
fi

cmd=$( echo "${stdout}" | grep -P '^\ttailscale up ' | sed -E 's/^\t(.*)$/\1/g')
cmd="$(echo ${cmd} | sed -E 's/--exit-node-allow-lan-access=(false|true)//g')"

# set lan access if enabling exit node 
if [[ ! -z "${EXIT_NODE}" ]]; then 
    cmd="${cmd} --exit-node-allow-lan-access=true"
elif [[ ! -z "${EXIT_NODE_CLEAR}" ]]; then 
    cmd="${cmd} --exit-node-allow-lan-access=false"
fi 

echo "CMD: ${cmd}"
echo "Exit node: ${EXIT_NODE}"
$cmd

# save last if successful
if [ "$?" -eq "0" ] && [[ ! -z "${EXIT_NODE}" ]]; then 
    echo "${EXIT_NODE}" > ${CONFIG_PATH} 
fi

echo "[+] Complete"