wshop-uihe-part-A-2015-Dec-11.markdown

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UNESCO-IHE workshop - part A

This is part A of the Tutorial UNESCO-IHE workshop - 11 Dec 2015.

• Hands-on part A
  
  • 1. Access the user interface
    
  • 2. My first VM
    
  • 3. Persistence
    

a) Access the User Interface

The UI (short for User Interface) is the web site that allows you to manage your Virtual Machines (VMs) on the HPC Cloud. In this section you will personalise your UI account in these steps:

1. Logging in and changing your UI password.
2. Adding an "SSH key" to your profile. This will enable secure access in your VMs.

Let's start.

Login to the UI

• Pick the demo account account that corresponds to your team.

  • You will receive the password by the workshop organizers.
  • Your account will remain active until 21st of December.

• Open the UI page in your browser: https://ui.hpccloud.surfsara.nl/

• Log in with your demo username and password.

NOTE:

Your project for this tutorial is called wshop-uihe.

Change your password

Let's change now the initial password:

• Click the buddy icon that represents your account wshop-sXX (top-right corner of the screen).
• Click on Settings, then Update password button.
• On the new screen, type your new password twice and click the Change button to submit it.

Logout

• Click your buddy icon.
• Choose Sign Out.

From now on you can use your new password to login to the UI. Do so now.

Add ssh keys to your profile

Before launching your first VM, there is a last thing to arrange in your UI account: add an SSH key to your profile.
But what does this mean and why is it needed?

As an HPC Cloud user you have full control of your virtual machines (IaaS). This means that you are administrator in your own VMs, in other words root user.

In general, root users can access a machine with a password. However, passwords are not secure because they are easy to forget or be cracked. The SSH keys authentication is a method to allow you access a remote machine securely, without passwords.

Follow the steps below to add an ssh key to your profile:

• First generate an SSH key pair of files:
  • Start a terminal (in Mac/Linux) or GitBash (in Windows).
  • Check if you already have an SSH key pair stored in your laptop. Type:

ls -l $HOME/.ssh/

• If you see the files id_rsa.pub and id_rsa, skip the next command. If not, type the following command to generate a new SSH key pair:

# just press enter in every question that shows
ssh-keygen -t rsa -b 4096

NOTE:

This command will generate two files: a public key (id_rsa.pub) and a private key (id_rsa). You should see now the files in your $HOME/.ssh/ directory.

If you have problems creating the SSH keys, get help from the detailed guide Generate an SSH key.

Next, you will copy the public key (id_rsa.pub) to the UI, but you will keep the matching private key (id_rsa) safe in your laptop:

• Open your public ssh key file (id_rsa.pub) and copy the content to clipboard, e.g. cat $HOME/.ssh/id_rsa.pub
• Go to your user profile and select Settings from the buddy icon. In the dialogue that pops up, go to the Info page.
• Locate the section Public SSH Key, and click on the blue edit icon. Paste the content of your public ssh key (id_rsa.pub) file.
• Close the window. There is no Save button, but your public key is automatically stored in your profile.

NOTE:

Adding an SSH key to you profile is a one-time task. It is possible to use multiple keys for different VMs but there is no need to repeat this procedure for the rest of the tutorial.

b) My first VM

To start a virtual machine easily, we provide the HPC Cloud AppMarket. This repository contains common appliances for you to pick and use. In this section you will use the AppMarket to build your first VM with the following steps:

• Importing a pre-made disk, called Image, which includes a Linux operating system.
• Creating the description of your VM, called Template, which gives your VM the shape you want.
• Instantiating the Template to run your first Virtual Machine.
• Accessing your Virtual Machine and shut it down.

Let's run the first machine on the HPC Cloud.

Import a pre-made image from the AppMarket

• Login to the UI.
• Choose the AppMarket tab on the left menu of the screen and then Appliances.
• Choose the image: Ubuntu 14.04 Desktop. Click on the tick-box next to it.
• Click on the Import button at the top-right corner of the screen.
• A dialogue will pop up, asking you for a few details. Edit as follows:
  • Select the Datastore for the images: 104: local images ssd.
  • Image Name: Course Image.
  • Template Name: Course Template.
• Finally, click the Import button. This will start importing the appliance from the AppMarket. You can close this window.

Food for brain:

• When you click on the body of an appliance, you can see detailed information about that appliance. Can you see this detailed information about the appliance we are using in this exercise?
• When you import an appliance, this will create (at least) one image and one template, as explained during the presentation. In the UI you have an Images tab and another Templates tab under the Virtual Resources option on the left menu. You should see your new image and template there.

• Can you see them?
• What is the STATUS of the image just after it you import it?
• Refresh with the sign next to the green plus button until it is READY.

Edit the Template

When you imported the appliance from the AppMarket, it created an image and a template for you. In the template you can define how many cores you want your VM to have, how much RAM memory, what storage drives, which network connections, etc. Following the instructions of the extended information of the appliance that you imported, we will have to adapt the template before we can use it to create VMs out of it.

Edit the imported template with these steps:

• Go to the Templates tab under the Virtual Resources on the left menu.
• Find the template you just imported, and click on it (anywhere except the tick-box).
• Click on the Update button on the top-right of the screen to start editing the template.
• Browse through the different tabs there (i.e. General, Storage, Network). Leave the default values, except for the following:
  • Select the Network tab which shows the network interfaces (or nics) for your VM. Select the row Name: internet (click once on it). You can see the feedback below:
    
• Click the green button Update at the top, to save your changes.

Start the VM

A template is just a description of a virtual machine that we want to build. Let's create the actual virtual machine from it.

• Go to the Virtual Machines section on the left menu. This displays an overview of all the existing VMs that you have the right to see. This list is (probably) empty at the moment.
• Click on the green plus sign to bring up a pop-up dialogue to create a VM.
• Give your virtual machine a name: My First VM.
  This name is also used as the host name of your machine.
• Number of instances: 1.
• Select the Course Template (click once on it). Since this is your first template, there is only one item in the list. You can see the feedback below:
  
• Click on the Create button at the bottom of the screen.
• Refresh the VM status by clicking on the symbol of the two arrows chasing each other next to [+] button.

NOTE:
Your VM will appear in the list of virtual machines. At first, it will have the state PENDING. The HPC Cloud is looking for a place where your virtual machine can actually run. Finding the right place depends on the amount of cores, memory, and disk that you asked in the template. Keep refreshing the list by clicking on the symbol of the two arrows chasing each other next to [+] button. When the required capacity becomes available, your VM will show the status RUNNING. Only then can you actually use your VM.

What happened?

Congratulations! You have just created a fresh, clean virtual machine!

Let's summarise what you have seen so far. From the menu on the left side, click on each of the tabs to inspect the information. A vertical blue bar to the left of one (and only one) tab tells you which one you are currently seeing.

• Dashboard: shows an overview of the project status, like the amount of running machines or usage statistics.
• Virtual Resources:
  • Images: this is the equivalent of a hard drive. Your OS is stored on this image.
  • Templates: the template gives your VM the shape you want. A template is just a recipe; not the machine itself.
  • Virtual Machines: here you can manage your VMs (i.e.: create, start, shutdown). Click anywhere on a running VM's row (except the tick-box, that is). Inspect the information tables that appear which show extended details.

Login to the VM

You can interact with your VM with several ways: command-line (e.g.: SSH), VNC (UI in your browser) or a remote desktop. We will use SSH in a terminal for the moment.

The way to login into your virtual machine is the ssh keys that you stored in your profile previously.

Command-line access - SSH

• First find the IP address of your virtual machine. Your VM's IP address is shown on in the IPs column from the virtual machines list on the UI.

• On your laptop, start a terminal (in Mac/Linux) or GitBash (in Windows).

• In your terminal, to connect to your VM, type:

ssh [email protected] # replace with your IP address!

First login

If everything went well, the first time you try to login your terminal will ask you to add the VM's IP to the list of known hosts. Type Yes, in that case.

You should now see a similar line in your terminal: ubuntu@ip-145-100-59-XYZ:~$

This means that you are logged in successfully to your Virtual Machine!

• Look around a bit, make yourself familiar with the system:

ubuntu@ip-145-100-59-XYZ:~$ ls /
ubuntu@ip-145-100-59-ZYZ:~$ cd /home/ubuntu/

• Create a file:

ubuntu@ip-145-100-59-XYZ:~$ echo "Some text ..." > myfile
ubuntu@ip-145-100-59-XYZ:~$ cat myfile

• Logout by typing logout or ctrl-D in your terminal (do NOT issue any shutdown command):

ubuntu@ip-145-100-59-XYZ:~$ logout

Food for brain:

Log in to your VM again. Is your file still there?

First shutdown

Let's shut your first VM down. Anytime you expect your VM to become idle, you should shut it down to stop consuming these resources that your VM is holding but not using.

• On the UI, Tick the box to the left on the row with your VM.
• At the upper right corner of the screen, under the dust bin drop-down button, click Shutdown.
• Refresh (by clicking on the two arrows chasing each other next to + button) until your VM is gone from the list. It will be removed from the display, but you can start it again whenever you need it.

Food for brain:

Check and refresh the Images and Templates tabs. Are your image and template still there?

c) Persistence

Images can be persistent. We say they are persistent when the persistent box is ticked on the UI and non-persistent when the persistent box is not ticked.

• What does persistent mean?

  • Changes by the VM are copied back to the original image (upon normal VM shutdown)
  • If a VM is running with a persistent disk, you cannot launch a second VM using that image

• What does non-persistent mean?

  • Changes by a VM are lost at shutdown and not copied back to the original image
  • It is possible to run multiple VMs using the same single non-persistent image

Food for brain:

Was the first image that you imported persistent or wasn't it?

In this section you will work with persistent images. You will go through these steps:

• Making your image persistent.
• Starting a VM using the persistent image.

Make your image persistent

• Go to Images tab under Virtual Resources on the left menu, and click anywhere (except the tick-box, that is) on the row for the image you created before that you named Course Image .
• Under the Information section, find the Persistent attribute. It says No, at the moment.
• Switch the value to Yes.

Start a persistent VM

• Start your virtual machine again.
• Log in and check the files you created during the previous run (first VM).

Food for brain: During the previous run, the VM's disk was non-persistent. From now on, you can store data in your VM that will be written on the backing image even if you restart your VM. Try it.

Note:

Your running VMs are exclusively occupying resources (and hence, consuming quota from your group even though we haven't explicitly made you aware of it in the course material) whether they are doing something useful or are idle. Because the HPC Cloud is offered on a fair-share basis and other users may actually be needing resources that you may be holding, before you move to the next part of this workshop, please remember to shut all your VMs down.

d) Bonus food for brain

This section is meant as extra questions that we thought would be nice for you to investigate, and we invite you to do/think about them even after the workshop is finished.

Bonus 1: The HPC Cloud has hundreds of users. Many of them have common questions. In order to address these we have put together a web site with some documentation for users. We call it the HPC Cloud Documentation. Do you know the URL of this web site? Make sure you find out!!!

Bonus 2: In Part A of the workshop (this page) you have explored the UI and learnt how to import an appliance from the AppMarket. However, many people come to the HPC Cloud because they can install and run their own operating system. In particular, Windows is very popular among UNESCO-IHE users.

• Can you think of (and sketch) the steps that you would need to follow to create a VM running your favourite operating system?
• Can you find three articles in the HPC Cloud Documentation that show how to install different operating systems from scratch?

Next: part B

Now that you have completed the Tutorial UNESCO-IHE - Part A (morning), you are ready to move on and continue with Tutorial UNESCO-IHE - Part B (afternoon).