Example of opening a ssh tunnel for a web app

tunnel.sh

#!/usr/bin/env bash

# Provides an example of how to setup a ssh tunnel on WSL

LOCAL_PORT=8080
REMOTE_HOST='localhost' # remote server may be the server being connected to (remote localhost) OR it could be a different server
REMOTE_PORT=8080
SSH_ADDRESS='appserver' # this can be user@hostip or an alias configured in ssh config file.

if [ "$1" == "-k" ]; then
    pid=$(netstat -lpnt 2>/dev/null | grep $LOCAL_PORT | grep --only-matching -e ' [0-9]*/docker-prox' | grep --only-matching -e '[0-9]*' | head -1)
    [ -z $pid ] && pid=$(lsof -i -P 2>/dev/null | grep -e 'ssh.*LISTEN' | awk '{print $2}' | head -1)

    [ ! -z $pid ] && kill $pid || echo "Unable to determine running instance to kill"
    exit
fi

if (nc -z localhost $LOCAL_PORT); then
    echo -e "Tunnel already exists on port $LOCAL_PORT\nAccess at http://localhost:$LOCAL_PORT\n"
else
    ssh $SSH_ADDRESS -N -f -L $LOCAL_PORT:$REMOTE_HOST:$REMOTE_PORT

    if ( nc -z localhost $LOCAL_PORT ); then
        echo -e "\nTunnel Created on Port $LOCAL_PORT\nAccess at http://localhost:$LOCAL_PORT"
        # open browser
        #"/mnt/c/Program Files/Google/Chrome/Application/chrome.exe" --profile-directory="Profile 1" 'http://localhost:$LOCAL_PORT'
    else
        echo "ERROR: Failed to create tunnel"
    fi
fi