Course VM Setup

Initial Password Change

You should have received an email giving you the IP address VM-IP of your VM, your login id VM-ID and your initial password VM-PW. Since your password has been exposed in an unsecure email, it must be changed ASAP. Hence you should immediately login to your VM and change your password to some VM-NEW-PW of your choosing.

1. Ensure that your workstation is connected to the campus network, possibly using the campus VPN.

2. Use ssh to connect to your VM using the provided IP address VM-IP and initial password VM-PW.

   If your workstation runs Linux or OS/X, you can do so using a command-line ssh client. If your workstation runs Windows, you can use Windows Terminal from the MS store. There is even an ssh app which you can install for your Chrome browser; this should work for all OS's which support Chrome.

   [Irrespective of the course you are registered for, you will notice that your VM has a name starting with CS444; it was set up this way for the convenience of the sysadmin and should not make any difference to you.]

3. Use the passwd command on your VM, to change your password to VM-NEW-PW.

Once you have logged in to the campus VPN as in (1) above, the following log shows how you would perform steps (2) and (3):

# from a linux or os/x terminal (windows will differ).
$ ssh VM-ID@VM-IP
The authenticity of host 'VM-IP (VM-IP)' can't be established.
ECDSA key fingerprint is ...
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'VM-IP' (ECDSA) to the list of known hosts.
VM-ID@VM-IP's password: VM-PW   #will not be echoed
Welcome to Ubuntu 22.04 ...
...
# at this point you should be connected to your VM.
VM-ID@COURSE-VM-ID:~$ passwd  #passwords not echoed below
Changing password for VM-ID.
(current) UNIX password: VM-PW
Enter new UNIX password: VM-NEW-PW
Retype new UNIX password: VM-NEW-PW

SSH Access Without Using a Password

If your workstation does not already have a public/private ssh keys set up, generate one using the method appropriate for your workstation's OS and then copy over the public key to your VM.

On a unix-based OS like linux or OS/X this can be done using ssh-keygen to generate the public/private keypair and then using ssh-copy-id to copy your public key to your workstation.

Verify that you can ssh from your workstation to your VM without needing to type your password.

X2Go Access to your VM

If you only use ssh, you basically obtain only command-line access to your VM. But you will need GUI access to your VM as the course progresses and are required to verify that you have set up GUI access in your submission for Project 1. The most convenient access is provided by x2go. (The end of this document lists some alternatives in case you just cannot get x2go to work.)

1. Install a X2Go client for the workstation you are using to access your VM if one is not already installed (note that a x2goclient command is available on remote.cs).

2. Start the x2goclient.

3. Create a session for connecting to your VM by clicking Session -> New session. Fill in the following fields:

   Session name

   webprog vm

   Host

   Your VM's IP address VM-IP

   Login

   Your login id VM-ID on your VM (if different from your login id on your workstation).

   Auto Login

   Select Try auto login (via SSH Agent or default SSH key) (this assumes that you have correctly set up password-less login from your workstation to your VM).

   Session type

   LXDE.

4. You should now be able to use the above session to access your VM using a GUI. You should not require a password if you have set up the ssh keys.

The following is a screenshot of my x2go configuration for accessing my VM from within the campus network (or VPN):

With the above setup, I do not need to type in a password when connecting to my VM.

When disconnecting from x2go, use the Suspend control (the widget which looks like a pause control, with two lines) on the blue x2go window. This will ensure that you can pick up where you left off when you reconnect to your VM. Do not shutdown your VM (you will need to restart it manually using the VSphere Web Client).

Setting Your npm Shell

To set the shell used by npm to bash, use the following command:

$ npm config set script-shell /usr/bin/bash

This will update your ~/.npmrc and npm will use bash to run scripts in the future.

Restarting your VM

In case you accidentally shutdown your VM or simply find it unreachable, you can use your VM's web console to restart it.

1. Use all except the last step the instructions for the vSphere Web Client to get access to your VM.

2. Use the Actions->Power menu item to restart your VM.

Debugging VM Connectivity Issues

If you cannot connect via x2go to your VM, please try the following:

1. Verify that your workstation's internet connection is working by accessing some web site not related to the university.

2. Connect your workstation to the campus VPN.

3. Use ssh to connect to remote.cs. If you are unable to do so, check to see whether you may have triggered fail2ban. If all else fails, go to the CS SysAdmin page for assistance.

4. From remote.cs, ssh to your VM using its IP address. If this succeeds, then there is a problem with x2go. If this fails, then your VM is down; restart it using the vsphere web client.

5. If the problem appears to be x2go, try shutting down your x2goserver using the power button on your x2goclient or by restarting your VM as per the previous step.

   Some students using OS/X workstations have found that:

   1. Rebooting your mac may help.

   2. More drastic: Reinstalling x2go and xquartz solves x2go problems.

6. One workaround for OS/X. If you have xquartz installed, but x2go is not installed or not working, you can display GUI applications running on remote.cs on your mac by using the -Y option when connecting to remote.cs using your OS/X terminal.

If all else fails, please send me an email giving your VM's IP and describe your workstation's environment. Please detail the responses to each of the above steps.

Administering Your VM

Your VM-ID account has administrative privileges. You can run any administrative CLI command by preceeding that command by sudo at which point you will be prompted for your current password. If you run an administrative task using the GUI, you will again be prompted for your current VM password.

Besides your account, you will find that the VM has two additional accounts. You should not touch these accounts. If something goes wrong with your VM, we may be able to use these accounts to get login to your VM and attempt to fix the problem.

You can install additional system-wide software packages using the command line using apt or using a GUI-program found on the system menu.

The VM has text editors/IDEs like Visual Studio code, emacs, gedit, nano, sublime and vim already installed. However, you may want to use the above package manager to install a text editor or IDE of your choice.

It is a good idea to keep the software on your VM up-to-date. Every few weeks, you should update:

$ sudo apt update
$ sudo apt upgrade

Check whether you need to reboot:

$ cat /var/run/reboot-required

If this file exists, the above command will tell you whether a reboot is required. To reboot, first backup all work, shutdown all applications running within your VM and then simply reboot:

$ sudo shutdown -r now

Your GUI session will lock up. You will need to escape out of it; you should be able to get back in within a couple of minutes. If something goes wrong please use the vsphere console to debug.

Other Remote Access Methods

If, for some reason, you just cannot get x2go to connect to your VM, you can try using one of these other methods of obtaining GUI access to your VM.