SSH Tunnel Manager

A lightweight Go service to manage SSH tunnels and ensure they stay active.

✨ Features

• Simple YAML-based configuration for defining tunnels.
• Monitors and maintains SSH tunnels to ensure they're always up.
• Supports two implementations for SSH tunneling:
  • Native: Uses a library-based implementation of SSH.
  • Wrapped: Uses the ssh command-line tool via exec.

---

⚙️ Configuration

The configuration is defined in a YAML file. A sample configuration can be found in the file example-config.yaml

Configuration Fields

Top-Level Fields

• type: Specifies the implementation for SSH tunneling. Options are:
  • native: Uses a library-based SSH implementation (default).
  • wrapped: Uses the ssh command-line tool via exec.
• defaultUser: Default username for SSH connections (optional if specified per tunnel).
• defaultBindIP: Default bind address for local forwarding (e.g., 127.0.0.1).
• defaultPrivateKeyPath: Path to the default private key for SSH authentication.
• defaultPassPhrasePath: Path to the file containing the passphrase for the private key.

Tunnel-Specific Fields

Each tunnel can override the default configuration:

• name: Unique identifier for the tunnel.
• user: (Optional) Username for SSH login. If not provided, the defaultUser is used.
• host: Remote server (hostname or IP address) to connect to via SSH.
• hostIP: Address of the target service on the remote machine. This is the internal IP or hostname on the remote side that the traffic will be forwarded to.
• hostPort: Port of the target service on the remote machine.
• bindIP: (Optional) Local IP address on the client (your machine) where the tunnel will listen. Defaults to defaultBindIP. Common values:
  • 127.0.0.1: Makes the port accessible only locally.
  • 0.0.0.0: Makes the port accessible from all network interfaces.
• bindPort: Local port on the client where the tunnel will listen.
• privateKeyPath: (Optional) Path to the private SSH key used for this tunnel. If not specified, the defaultPrivateKeyPath is used.
• passPhrasePath: (Optional) Path to the file containing the passphrase for the private key. If not specified, the defaultPassPhrasePath is used.

🚀 Installation

To set up the SSH Tunnel Manager, follow these steps:

Building the Docker Image

To build the Docker image, use the following command:

    task docker:build

This will create a Docker image with the SSH Tunnel Manager pre-configured for use.

Deployment with Systemd and Docker Compose

1. Customize the files:

   • docker-compose.yaml
   • ssh-tunnel-manager.service

2. Copy the customized systemd unit file to your system's systemd directory, reload systemd, and start the service:

   sudo cp ssh-tunnel-manager.service /etc/systemd/system/
   sudo systemctl daemon-reload
   sudo systemctl enable ssh-tunnel-manager
   sudo systemctl start ssh-tunnel-manager 

---

This installation method leverages docker-compose and systemd for a reliable, integrated deployment.