tunnel

#!/bin/bash

# mysql tunnel to remote server via jumphost

# ports on the jumphost servers
Ports[1]=10008
Ports[2]=10009
Ports[3]=10010
Ports[4]=10011
Ports[5]=10012
Ports[6]=10013
Ports[7]=10014

# jumphost server
JUMPHOST=''

count=${#Ports[@]}
if [[ -z $1 || $1 -gt $count || $1 -lt 1 ]]; then
    echo -e 'Usage:\ntunnel VipNo [LocalPort]'
    echo 'default LocalPort = 3306'
    echo -e '\nJumphosts ports:'
    echo -e "\nVipNo\tPort\n"
    for (( i = 1 ; i <= $count ; i++ ))
    do
        echo -e $i "\t("${Ports[$i]}")"
    done
else
    if [ -z $2 ]; then
        LocalPort=3306
    else
        LocalPort=$2
    fi
    
    portCheck="ssh -fNg -L $LocalPort:127.0.0.1:"
    oldPID=`ps ax | grep "$portCheck" | grep -iv "grep" | cut -d"?" -f1`
    
    if [ -z $oldPID ]; then
        echo 'No previous process found, setting tunnel...'
    else
        echo "Found previous tunnel bound to port $LocalPort (pid $oldPID), refreshing tunnel..."
        kill -15 $oldPID
        if [ "$?" = "0" ]; then
            echo "Process killed successfully"
        else
            echo "Cannot kill process $oldPID, you need to kill it manually"
            exit 1
        fi
    fi
    
    ssh -fNg -L $LocalPort:127.0.0.1:${Ports[$1]} $JUMPHOST
    
    if [ "$?" = "0" ]; then
        echo "Tunnel ready"
    else
        echo "Tunnel cannot be created"
        exit 1
    fi
fi