Simple Socat Manager Web UI

A simple web application written in Go to manage socat TCP forwards through a user-friendly web interface. Start, stop, and monitor multiple socat listeners/forwards without needing complex command-line management.

This tool provides a web UI to dynamically create TCP forwards using socat. You provide a local IP and port for socat to listen on, and a remote IP and port for socat to forward traffic to. The application manages these socat processes, allows you to stop them individually, and keeps track of their status.

It's particularly useful for temporarily forwarding ports during development, testing, or network troubleshooting scenarios.

• Web Interface: Clean UI for managing forwards.
• Start Forwards: Easily start new socat tcp4-listen <...> tcp4:<...> forwards.
• Input Validation: Validates IP address formats and port ranges (1-65535) before attempting to start socat.
• List Active Forwards: Displays a table of currently running forwards managed by the application, including PIDs.
• Stop Forwards: Stop individual socat processes with a button click.
• Process Monitoring (Linux): Automatically checks if managed socat processes are still running using the /proc filesystem. Dead processes are removed from the list.
• Event Log: Displays a running log of events:
  • Start: A new forward was successfully started.
  • Stop: A forward was manually stopped via the UI.
  • Dead: A previously running forward's process was detected as no longer running.
• In-Memory State: Process list and event log are stored in memory (cleared on application restart).
• Single Binary: Compiles to a single executable for easy deployment.

1. Go: Version 1.18 or later installed (https://go.dev/doc/install).
2. Socat: The socat utility must be installed on the host machine and accessible via the system's PATH. You can usually install it via your package manager (e.g., sudo apt install socat or sudo yum install socat).
3. Operating System: Linux is required for the automatic dead process detection feature, which relies on the /proc filesystem. The core functionality might work on other Unix-like systems, but process monitoring may fail.

1. Clone the repository:

   git clone github.com/mubix/socatmanager
   cd socatmanager

2. Initialize Go Modules (if needed): If you haven't already, initialize Go modules in the project directory:

   go mod init mubix.com/socatmanager

3. Fetch Dependencies: The application uses github.com/google/uuid. Fetch it:

   go mod tidy

Compile the application into a single binary:

go build -o socatmanager main.go
# Or simply:
# go build

This will create an executable file named socatmanager in the current directory.

1. Execute the binary:

   ./socatmanager

2. Access the Web UI: Open your web browser and navigate to: http://localhost:8080 (or the appropriate hostname/IP if running remotely).

The server will start logging output to your console.

• Running in the Background (Optional): For longer-term use, you might want to run it using nohup, screen, tmux, or set it up as a systemd service:

  nohup ./socat-manager &

1. Navigate to http://localhost:8080 or the IP of the server you are running it on.
2. Start a Forward:
   • Fill in the "Base IP" (IP address for socat to bind to, e.g., 0.0.0.0 or 192.168.1.100). This needs to be an IP address that the sever can actually bind to.
   • Fill in the "Base Port" (Port for socat to listen on, e.g., 4444).
   • Fill in the "Remote IP" (Target IP address to forward traffic to).
   • Fill in the "Remote Port" (Target port to forward traffic to).
   • Click "Start Socat Forward".
   • If successful, the page will refresh, and the new forward will appear in the "Running Forwards" table. Errors (validation or socat startup) will be displayed at the top.
3. View Forwards: The "Running Forwards" table shows details (Base/Remote IPs & Ports, PID) for each active socat process managed by this tool.
4. Stop a Forward: Click the "Stop" button next to the desired forward in the table. The page will refresh, the process will be terminated, and a "Stop" event will appear in the log.
5. Monitor Events: The "Event Log" section shows a timestamped history of Start, Stop, and Missing events for the current application session.

• Port: The web server listens on port 8080 by default. This is currently hardcoded in main.go. To change it, modify the port variable in the main function and rebuild.

• Error: "socat command not found": Ensure socat is installed correctly and its location is included in your system's PATH environment variable for the user running socat-manager.
• Error: "Failed to start socat (check if address/port is already in use...)": The specified "Base IP" and "Base Port" combination is likely already being used by another application (or another socat instance). Choose a different Base Port or stop the conflicting process. It could also indicate a permissions issue preventing socat from binding to the requested address/port.
• Forwards marked "Dead" unexpectedly: This means the application checked /proc/<PID>/cwd and found the process was gone. Check system logs (dmesg, /var/log/syslog, etc.) or socat's behavior if it's crashing. This can happen is the socat process is killed, segfaults, or fails to start (bad Base IP).
• Application doesn't start / Port conflict: Ensure port 8080 (or the configured port) is not already in use by another service.

This project is licensed under the BSD 3-clause License.