remote_proxy_ssh.sh

#!/bin/bash

# The ip to ssh to to have remote ssh setup on
remote_ip=$1
# The remote username to ssh as
remote_user=$2
# The port to connect to the remote host on
remote_port=${3:-22}
# The port to open on the remote host to listen on
remote_listen_port=${4:-2222}

PID_FILE=~/.remote_ssh_proxy.pid

usage="${BASH_SOURCE[0]} <remote_ip> <remote_user> [<remote_port:22> <remote_listen_port:2222>]"
if [ -z $remote_ip ]; then
  echo $usage
  exit 1
fi

if [ -z $remote_user ]; then
  echo $usage
  exit 1
fi

function run() {
  remote_user=$1
  remote_ip=$2
  remote_port=$3
  remote_listen_port=$4
  pod_file=$5

  ssh -f -N $remote_user@$remote_ip -p $remote_port -R ${remote_listen_port}:localhost:22 &
  PID=$(ps -ef | grep 'ssh -f -N' | awk '!/grep/ {print $2}')
  echo $PID > $pid_file
  echo "remote ssh proxy should be running"
}

while sleep 15; do
  # Pid file exists and has pid in it. Process should be running
  if [ -f $PID_FILE ]; then
    PID=$(cat $PID_FILE)
    echo "PID: $PID"
    if [ -n $PID ]; then
      # ssh process is already running
      if ps -f -p $PID | grep -v 'STIME'; then
        echo "Looks like ssh is already running. Refusing to run it again(it would just error anyways)"
        echo "If this is an error you might try to kill it with:"
        echo "kill -9 $PID"
        exit 1
      else
        run $remote_user $remote_ip $remote_port $remote_listen_port $PID_FILE
      fi
    else
        run $remote_user $remote_ip $remote_port $remote_listen_port $PID_FILE
    fi
  else
    run $remote_user $remote_ip $remote_port $remote_listen_port $PID_FILE
  fi
done