How to Run Direct Print Client on a Headless Ubuntu or Debian Server?

When to Use Headless Mode

Running the VentorTech Direct Print Client in headless mode is recommended when:

• The server has no graphical desktop environment (GUI)

• The client runs on a dedicated print server

• The system is managed via SSH or terminal access

In such environments, the Direct Print Client cannot start normally and may fail with an error similar to:

qt.qpa.xcb: could not connect to display
qt.qpa.plugin: Could not load the Qt platform plugin "xcb"
This application failed to start because no Qt platform plugin could be initialized.

This happens because the Direct Print Client is built with Qt, a framework used to create graphical desktop applications. Such applications normally expect a graphical environment to be available.

To run the client on a headless server, you need to use headless mode, which allows the application to work without a GUI.

Running Direct Print Client in Headless Mode

On a headless Ubuntu or Debian server, start the Direct Print Client using the following command:

./DirectPrintClient --headless --web-interface

This starts the client without a graphical interface and enables the built-in web interface.

Accessing the Web Interface

After starting the client with the command above, the Direct Print Client will expose its web interface at:

http://localhost:8888

From this interface you can:

• Sign in to your PrintNode account

• Verify that printers are detected

• Configure the Direct Print Client

• Monitor printing activity

If you are connecting remotely to the server, you may need to open or forward port 8888.