Setting up a virtual desktop for your instance

This is an example of what can be achieved on Nimbus Research Cloud. The detailed configuration for various VM flavours and OS configurations might differ. Nimbus users are responsible for managing their VMs and installing tools. We believe that this step-by-step example might be helpful to run a graphical user interface for your Nimbus instance.

This guide will walk through how to establish a graphical user interface (i.e. point and click) virtual desktop using X2Go Client. First, we will establish the X2Go server on your instance, and then we will install X2Go on your local machine and connect.

Step by step guide (X2Go Server):

Ubuntu Instance

On your Nimbus instance, we will install X2Go and update our packages
```
sudo apt-get install x2goserver
```
Now, we install extra bindings for the desktop environment. This adds extra useful features. There are several options (LXDE, MATE, GNOME, KDE, XFCE) but we will choose XFCE.
```
sudo apt-get install xfce4
```
Next we need to check that the X2Go server is running in the background. We can check with the following command
```
service --status-all | grep x2go
```
The expected output is
```
[ + ]  x2goserver
```
If the server is not running, you can start it with the following
```
sudo service x2goserver start
```
If this does not work, try restarting your instance before doing anything else, using sudo reboot

CentOS Instance

On your Nimbus instance, update all software packages

sudo dnf update
sudo dnf install epel-release
sudo dnf config-manager --set-enabled powertools

Install the XFCE desktop environment
```
sudo dnf groupinstall xfce
```
Install the X2Go server
```
sudo dnf install x2goserver
```

Step by step guide (X2Go Client):

Now, time to install the X2Go Client on your local machine if you don't have it already. Installation is operating system specific.
1. Ubuntu: Install the client by typing into a terminal on your local computer:
```
sudo apt-get install x2goclient
```
2. Windows: Download and install the newest windows client from the X2Go website. Follow the installation wizard’s steps, you may keep all default options.
3. Mac OS X: You will need to download and install the newset version of the OS X X11 server called XQuartz from the XQuartz website or download.cnet.com (search fot XQuartz). If you are notified to restart your machine, wait until making the following changes. Open the XQuartz server by clicking on its icon, then go to preferences. In the security tab, click the box to enable "allow connections from network clients". You can then download and install the newest X2Go client from the X2Go Website.
Now we will start the X2Go Client and connect it to the VM. This is again operating system specific.
1. On Linux, search in your application menu, or simply type into your local computer’s terminal:
```
x2goclient
```
2. On Windows and Mac, start the application as you do with any other program (find the x2goclient application). E.g. on Mac, bring up the spotlight (Cmd + Space) and search for “x2goclient”.
The session settings should come up right away if you are using the client for the first time. If you are not, click on “New session”, which is the top left button that looks like a blank sheet of paper.
Follow the example image to fill in your desired session name, IP address of your VM, and path to your nimbus SSH key. The user name should always be ubuntu, and the port should always be 22. Change the session type to XFCE. Click “OK” to get to the X2Go Start Window. If asked whether to trust the host, click “Yes”. You can then click on the box with your session name on the right, and the client will try to connect to your instance’s remote desktop. You will have to type in your ssh key passphrase. This may take a few minutres if it is the first time you are connecting.

Troubleshooting

Some users have reported that using an older version of X2Go has resolved issues for them. If you're experiencing trouble with X2Go, rolling back to a previous version might work for you.