[Web service] desktop on a page (virtual machine)

Introduction

Hosted by laitos web server, the service starts a virtual machine that offers a fully functional computer desktop completed with productivity suites and web utilities - all in a single web page.

It is often useful for:

• General web browsing.
• Perform simple office tasks such as word processing and scientific calculation.
• Enable outdated computers (e.g. Windows 95 + Mosaic browser) to enjoy rich experience of modern computer desktop.

Configuration

Construct the following properties under JSON key HTTPHandlers:

1. A string property called VirtualMachineEndpoint, value being the URL location that will serve the service. Keep the location a secret to yourself and make it difficult to guess.
2. An object called VirtualMachineEndpointConfig that has the following properties:

Property	Type	Meaning	Default value
LocalUtilityPortNumber	integer	An arbitrary number above 20000 and below 65535. It must not clash with port numbers used by other other components, such as the web-browser-on-a-page.	(This is a mandatory property without a default value)

Here is an example:

{
    ...

    "HTTPHandlers": {
        ...

        "VirtualMachineEndpoint": "/very-secret-my-desktop",
        "VirtualMachineEndpointConfig": {
            "LocalUtilityPortNumber": 15499
        }

        ...
    },

    ...
}

Run

The service is hosted by web server, therefore remember to run web server.

Usage

In a web browser, navigate to VirtualMachineEndpoint of laitos web server.

To start the desktop (virtual machine):

• Click "Download OS" to download the default desktop OS (Puppy Linux). This only has to be done when laitos server starts for the first time.
  • If you wish to use an alternative desktop OS, enter the download URL of its ISO medium into the text box before clicking "Download OS" button.
  • Click "Refresh Screen" periodically to check the download progress.
• After download finishes, click "Start" to start the desktop.
• Click "Refresh Screen" regularly to view desktop screen.

To use mouse:

• On the desktop screen picture, click at a location of your interest. If your web browser does not understand javascript, you will have to manually enter the location coordinates into X and Y text boxes.
• Click on a mouse control button, e.g. "LClick" sends a left mouse click at the coordinates, and "Move To" moves mouse cursor to the coordinates.

To use keyboard:

• Enter codes of keyboard keys that are to be pressed simultaneously into the text box.
• Click "Press Simultaneously" to send the key presses to the desktop.
  • If you wish to type words such as "Helsinki", enter two sets of keys "h e l s i n k" and then "i".

Tips

• Make the endpoint difficult to guess, this helps to prevent misuse of the service.
• The local utility port number from configuration is only for internal localhost use. It does not have to be open on your network firewall.
• laitos server has to have QEMU or KVM installed in order to start the desktop virtual machine. You may rely on system maintenance to automatically install the software for you.
• laitos server prefers to use KVM to start the desktop virtual machine as KVM offers enhanced performance. If KVM is not available, laitos will fall back to QEMU automatically.
• The desktop virtual machine works better with a lightweight Linux distribution ISO medium. The well-known lightweight PuppyLinux works very well, and it is used as the default ISO download URL.
• After the virtual machine starts up, it remains running indefinitely until it shuts itself down (e.g. from VM's Start menu), or the user shuts it down forcibly with the "Kill" button from the web controls.