Socat Manager

⚡ A simple, centralized socat manager for Linux. Solves the classic problem of Docker containers being unable to access services listening on the host's localhost (127.0.0.1).

This project provides a one-click installation script to set up a systemd service that manages multiple socat port forwarding rules from a single, easy-to-edit configuration file.

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The Problem It Solves

By default, Docker containers on Linux cannot connect to services that are bound to the host machine's loopback address (127.0.0.1). This is a security feature, but it creates a challenge when you want a container (like a reverse proxy) to access a service running on the host without exposing that service to other networks.

For example:

• A Nginx Proxy Manager container needs to forward traffic to a X-UI panel running on the host at 127.0.0.1:5000.
• A web application in a container needs to connect to a database running on the host at 127.0.0.1:3306.

This tool creates a clean and persistent "bridge" for such scenarios.

How It Works

The script sets up a single systemd service (socat-manager.service) that reads a configuration file located at /etc/socat/forwards.conf. For each rule defined in the config file, it starts a socat process in the background.

This creates a stable and manageable way to forward traffic from an IP accessible by Docker containers (e.g., the Docker bridge gateway 172.17.0.1) to the host's 127.0.0.1.

Traffic Flow: [Docker Container] -> [Host IP on Docker Bridge (e.g., 172.17.0.1)] -> [socat process] -> [Host Service on 127.0.0.1]

🚀 Quick Start: One-Click Installation

Run the following command as root or with sudo to install the Socat Manager on your Debian-based or RHEL-based system. The script will automatically install socat if it's not present.

bash <(curl -sL https://raw.githubusercontent.com/Yeliaoyuan/socat-manager/main/install_socat_manager.sh)

Note: Please replace YourGitHubUsername with your actual GitHub username once you've created the repository.

⚙️ Configuration

After installation, all you need to do is edit the configuration file to add your forwarding rules.

1. Open the configuration file:

   sudo nano /etc/socat/forwards.conf

2. Add your rules. The format for each line is: <Listen_IP>:<Listen_Port>:<Forward_IP>:<Forward_Port>

   Example: To forward traffic from 172.17.0.1:5000 to 127.0.0.1:5000:

   # Socat Forwarding Rules
   #
   # Format: <Listen_IP>:<Listen_Port>:<Forward_IP>:<Forward_Port>
   # Lines starting with # are ignored. Blank lines are ignored.
   
   # Forward port 5000 for X-UI panel
   172.17.0.1:5000:127.0.0.1:5000
   
   # Forward port 3306 for a local database
   # 172.17.0.1:3306:127.0.0.1:3306
   

3. Restart the service to apply the changes:

   sudo systemctl restart socat-manager.service

🛠️ Managing the Service

This is a standard systemd service. You can manage it with the following commands:

• Check the status:

  sudo systemctl status socat-manager.service

• View logs:

  sudo journalctl -u socat-manager.service -f

• Stop the service:

  sudo systemctl stop socat-manager.service

• Start the service:

  sudo systemctl start socat-manager.service

卸载 (Uninstall)

If you wish to remove the Socat Manager:

1. Stop and disable the service:

   sudo systemctl stop socat-manager.service
   sudo systemctl disable socat-manager.service

2. Remove the files:

   sudo rm /etc/systemd/system/socat-manager.service
   sudo rm /usr/local/bin/socat-manager.sh
   sudo rm -r /etc/socat

3. Reload the systemd daemon:

   sudo systemctl daemon-reload