Getting started on OpenShift Virtualization Training

Create a VM

Mon, 01 Jan 0001 00:00:00 +0000

Creating a virtual machine

In OpenShift’s web console in the menu on the left, navigate to Virtualization → Overview. Make sure your project is active:

It’s still pretty empty here and a lot of zeroes look at us. However, we are going to change this.

Task 1.1.1: Create your first virtual machine

Open the VirtualMachines menu entry. Click on Create VirtualMachine and choose From template.

On the left of the view that just opened, click on User templates and choose the Cirros VM template.

Start and stop a VM

Mon, 01 Jan 0001 00:00:00 +0000

In the previous section, we wrote a VirtualMachine specification and applied the manifest to the Kubernetes cluster.

Lifecycle

When the underlying technology libvirt refers to a VM it often also uses the concept of so-called guest domains.

According to libvirt.org , a guest domain can be in several states:

Undefined: This is a baseline state. Libvirt does not know anything about domains in this state because the domain hasn’t been defined or created yet.
Defined or Stopped: The domain has been defined but it’s not running. This state is also called stopped. Only persistent domains can be in this state. When a transient domain is stopped or shut down, it ceases to exist.
Running: The domain has been created and started either as transient or persistent domain. Either domain in this state is being actively executed on the node’s hypervisor.
Paused: The domain execution on the hypervisor has been suspended. Its state has been temporarily stored until it is resumed. The domain does not have any knowledge whether it was paused or not.
Saved: Similar to the paused state, but the domain state is stored to persistent storage. Again, the domain in this state can be restored and it does not notice that any time has passed.

Accessing the console

Mon, 01 Jan 0001 00:00:00 +0000

Console access

Make sure you are on your VM’s details page and that it is started.

Now open your VM’s console by clicking on Open web console. A new window opens. Wait for the console to connect.

You can now use the default credentials to log in:

User: cirros
Password: gocubsgo

Try executing a couple of commands, such as:

whoami
ping tim-koko.ch

Task 1.3.2: Entering the console using virtctl

By executing the following command in your openshift terminal, you can also use the virtctl cli to conncet to the virtual machines console:

Exposing VM Ports

Mon, 01 Jan 0001 00:00:00 +0000

In the previous chapter, we accessed our VM console using the virtctl tool. In this section we will expose the SSH port of our VM and access it directly.

Note

This can be done for any port you want to use. For example, if your virtual machine provides a webserver, you can expose the webserver port.

Checking available Services resources

As you see with the following command, creating the VM does not create any Kubernetes Service for it.

Changing files

Mon, 01 Jan 0001 00:00:00 +0000

In the previous chapter, we gained access to the VM’s console. In this chapter, we will use this access to make a change to our running VM and observe what happens if we restart the VM.

Task 1.5.1: Create a file

Connect to your VM’s web console.

touch myfile

Verify that the file really is present. Check it with:

stat myfile

Task 1.5.2: Restart VM

Exit the console and restart your VM.