Create Revers SSH Tunnel from local ubuntu machine

revers_ssh_tunnel.sh

#!/bin/bash

EC2_USER="sshtunnel"
EC2_HOST="your-ec2-public-ip"
EC2_PORT="22"
REMOTE_PORT="2222"
LOCAL_PORT="22"
KEY_PATH="/etc/sshtunnel/id_rsa"

sudo mkdir -p /etc/sshtunnel
sudo chmod 700 /etc/sshtunnel

sudo ssh-keygen -q -N "" -f $KEY_PATH

echo "Copying public key to EC2 instance..."
ssh-copy-id -i ${KEY_PATH}.pub -p $EC2_PORT $EC2_USER@$EC2_HOST

SERVICE_FILE="/etc/systemd/system/sshtunnel.service"
sudo bash -c "cat > $SERVICE_FILE" <<EOL
[Unit]
Description=Persistent Reverse SSH Tunnel to EC2
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
ExecStart=/usr/bin/ssh -i $KEY_PATH \\
  -o ServerAliveInterval=30 \\
  -o ServerAliveCountMax=3 \\
  -o ExitOnForwardFailure=yes \\
  -o StrictHostKeyChecking=no \\
  -o UserKnownHostsFile=/dev/null \\
  -N -T -R $REMOTE_PORT:localhost:$LOCAL_PORT $EC2_USER@$EC2_HOST
Restart=always
RestartSec=60

[Install]
WantedBy=multi-user.target
EOL

sudo systemctl daemon-reload
sudo systemctl enable sshtunnel.service
sudo systemctl start sshtunnel.service

echo "Reverse SSH tunnel setup complete."