ipsec vpn connection script. work with https://github.com/hwdsl2/setup-ipsec-vpn

connect.sh

#!/usr/bin/env bash

# output text colors
RED='\033[0;31m'
GREEN='\033[0;32m'
NC='\033[0m'

detect_current_connection(){
    result="$(ip route | grep 'default dev ppp' | awk '{print $3}')"
}

write_to_connection_file(){
    file="/var/run/xl2tpd/l2tp-control"
    if [ -f $file ]; then
        sudo chmod 777 $file
        echo "$1 myvpn" > /var/run/xl2tpd/l2tp-control
    else
        sudo sh -c "echo '$1 myvpn' >> /var/run/xl2tpd/l2tp-control"
    fi
}

connect () {
    detect_current_connection
    con=$result
    if [[ $con == ppp* ]]; then
        disconnect
    fi
    
    echo -e "${GREEN}Attempt to connect...${NC}"
    
    DefaultRoute=$(/sbin/ip route | awk '/default/ { print $3 }')
    MyPublicIp="$(dig +short myip.opendns.com @resolver1.opendns.com)"
    
    sudo service strongswan restart
    sudo service xl2tpd restart
    
    sudo ipsec up myvpn
    write_to_connection_file c
    
    # $MY_SERVER_IP was set permanently in /etc/environment
    vpn_server_ip_route="$(ip route show $MY_SERVER_IP | wc -l)"
    my_public_ip_route="$(ip route show $MyPublicIp | wc -l)"
    if [ $vpn_server_ip_route -eq 0 ]
    then
        sudo route add $MY_SERVER_IP gw $DefaultRoute
    elif [ $my_public_ip_route -eq 0 ]
    then
        sudo route add $MyPublicIp gw $DefaultRoute
    fi
    
    echo -e "${GREEN}Waiting For Service To Start...${NC}"
    while true
    do
        con="$(ip route | grep 'ppp' | awk '{print $3}')"
        if [[ $con == ppp* ]]; then
            sudo route add default dev $con
            echo -e "${GREEN}Connected to $con${NC}"
            break
        fi
        sleep 1
    done
}

disconnect () {
    echo -e "${GREEN}Attempt to disconnect...${NC}"
    detect_current_connection
    con=$result
    if [[ $con == ppp* ]]; then
        sudo route del default dev $con
        write_to_connection_file d
        sudo ipsec down myvpn
        echo -e "${GREEN}Disconnected From $con${NC}"
    else
        echo -e "${RED}No Device Detetcted...${NC}"
    fi
}

action=${1:-c}

if [ "$action" = "c" ]
then
    connect
elif [ "$action" = "d" ]
then
    disconnect
fi