How to log onto the courses Virtual machine from your Mac or Windows computer

This lesson covers how to log into, and out of, an virtual machine instance.

Background to the Virtual Machine

To save time, your instructor launched a remote computer (instance) for you prior to the workshop, and connected it to our lesson data.

To access the pre-configured workshop data, you’ll need to use our log-in credentials (user name and password). These credentials will be supplied by your instructor.

But first, you need a place to log into! To find the instance that’s attached to that data, you’ll need something called an IP address. Your instructor should have given this to you at the beginning of the workshop.

An IP address is essentially the numerical version of a web address like www.amazon.com

Connection Protocols

We will use a protocol called Secure Shell (SSH) that, as the name implies, provides you with a secure way to use a shell. In our case, the shell will be running on a remote machine. This protocol is available for every operating system, but sometimes requires additional software.

Logging onto the course virtual machine

Username will be training1 to trainingn (These will be assigned to you at start of course

along with the password for that username)

The machine that you will be connecting to is cruktraining.cruk.cam.ac.uk

Shortened machine name is ‘10.20.222.90’

e.g. ssh training5@cruktraining.cruk.cam.ac.uk

Connecting using Windows PC

Prerequisites: You must have an SSH client. There are several free options but you should have installed PuTTY.exe at the begining of the workshop, and we’re going to continue using that.

1. Open PuTTY

2. Paste in the ‘Host Name (or IP address)’ section the IP address provided by your instructor (or the IP address of an instance you have provisioned yourself)

   Keep the default selection ‘SSH’ and Port (22)

   

3. Click ‘Open’

   You will be presented with a security warning

   

4. Select ‘Yes’ to continue to connect

5. In the final step, you will be asked to provide a login and password

   Note: When typing your password, it is common in Unix/Linux not see any asterisks (e.g. `**) or moving cursors. Just continue typing

   

You should now be connected!

Connecting using Mac/Linux

Mac and Linux operating systems will already have terminals installed.

1. Open the terminal

   Simply search for ‘Terminal’ and/or look for the terminal icon

   

2. Type the following command substituting ip_address by the IP address your instructor will provide (or the IP address of an instance you have provisioned yourself)

    $ ssh dcuser@ip_address
   

   Be sure to pay attention to capitalization and spaces

3. You will receive a security message that looks something like the message below

    The authenticity of host 'ec2-52-91-14-206.compute-1.amazonaws.com (52.91.14.206)' can't be established.
    ECDSA key fingerprint is SHA256:S2mMV8mCThjJHm0sUmK2iOE5DBqs8HiJr6pL3x/XxkI.
    Are you sure you want to continue connecting (yes/no)?
   

4. Type yes to proceed

5. In the final step, you will be asked to provide a login and password

   Note: When typing your password, it is common in Unix/Linux not see any asterisks (e.g. ****) or moving cursors. Just continue typing.

You should now be connected!

Logging off a virtual machine

Logging off your instance is a lot like logging out of your local computer: it stops any processes that are currently running, but doesn’t shut the computer off.

To log off, use the exit command in the same terminal you connected with. This will close the connection, and your terminal will go back to showing your local computer:

dcuser@ip-172-31-62-209 $ exit

Amandas-MacBook-Pro-3 $

Logging back in

Internet connections can be slow or unstable. If you’re just browsing the internet, that means you have reload pages, or wait for pictures to load. When you’re working in cloud, that means you’ll sometimes be suddenly disconnected from your instance when you weren’t expecting it. Even on the best internet connections, your signal will occasionally drop, so it’s good to know the above SSH steps, and be able to log into our VM without looking up the instructions each time.

In the next section, we’ll also show you some programs that you can use to keep your processes going even if your connection drops. But for now, just practice logging on and off a few times.