k8s.github.io

Provisioning Compute Resources

Note: You must have VirtualBox and Vagrant configured at this point

Open a terminal application (on Windows use PowerShell). All commands in this guide are executed from the terminal.

Download this github repository and cd into the virtualbox folder

git clone https://github.com/kodekloudhub/certified-kubernetes-administrator-course.git

CD into the virtualbox directory

cd kubeadm-clusters/virtualbox

Run Vagrant up to create the virtual machines.

vagrant up

Bridge interface selection

Bridged networking makes the VMs appear as hosts directly on your local network. This means that you will be able to use your own browser to connect to any NodePort services you create in the cluster.

If your workstation has more than one network interface capable of creating a bridge, Vagrant may stop and ask you which one to use if it cannot determine the best interface itself. Now it should work this out and not have to ask you, however if it does not, then the “best” interface is the one used to connect to your broadband router. On laptops, this would normally be the Wi-Fi adapter which should be easliy identifiable in the list. The example below is from a Windows desktop computer with a wired network adapter.

Which of the two choices do you think is correct?

Reveal

> `Intel(R) Ethernet Connection (2) I219-V` Why? Because 1. Ethernet is the term often given to wired network connections. 2. The other one is Hyper-V which is internal and used for native running of VMs (could indeed be used instead of VirtualBox, but that's another story).

==> controlplane: Available bridged network interfaces:
1) Intel(R) Ethernet Connection (2) I219-V
2) Hyper-V Virtual Ethernet Adapter
==> controlplane: When choosing an interface, it is usually the one that is
==> controlplane: being used to connect to the internet.
==> controlplane:
    controlplane: Which interface should the network bridge to?

At the end of the deployment, it will tell you how to access NodePort services from your browser once you have configured Kubernetes. Make a note of this.

If you encountered issues starting the VMs, you can try NAT mode. Note that in NAT mode you will not be able to connect to your NodePort services using your browser without setting up port forwarding rules in VirtualBox UI.

Run
```
 vagrant destroy -f
```
Edit vagrantfile and change BUILD_MODE = "BRIDGE" to BUILD_MODE = "NAT" at line 10.

SSH to the nodes

There are two ways to SSH into the nodes:

1. SSH using Vagrant

From the directory you ran the vagrant up command, run vagrant ssh <vm> for example vagrant ssh controlplane.

This is the easiest way as it requires no configuration.

2. SSH Using SSH Client Tools

Use your favourite SSH Terminal tool (PuTTY/MobaXTerm etc.).

Use the above IP addresses. Username and password based SSH is disabled by default. Vagrant generates a private key for each of these VMs. It is placed under the .vagrant folder (in the directory you ran the vagrant up command from) at the below path for each VM:

Private Key Path: .vagrant/machines/<machine name>/virtualbox/private_key

Username/Password: vagrant/vagrant

Verify Environment

Ensure all VMs are up
Ensure VMs are assigned the above IP addresses
Ensure you can SSH into these VMs using the IP and private keys, or vagrant ssh
Ensure the VMs can ping each other

Troubleshooting Tips

Failed Provisioning

If any of the VMs failed to provision, or is not configured correct, delete the VM using the command:

vagrant destroy <vm>

Then re-provision. Only the missing VMs will be re-provisioned

vagrant up

Sometimes the delete does not delete the folder created for the VM and throws an error similar to this:

VirtualBox error:

VBoxManage.exe: error: Could not rename the directory 'D:\VirtualBox VMs\ubuntu-bionic-18.04-cloudimg-20190122_1552891552601_76806' to 'D:\VirtualBox VMs\kubernetes-ha-worker-2' to save the settings file (VERR_ALREADY_EXISTS)
VBoxManage.exe: error: Details: code E_FAIL (0x80004005), component SessionMachine, interface IMachine, callee IUnknown
VBoxManage.exe: error: Context: "SaveSettings()" at line 3105 of file VBoxManageModifyVM.cpp

In such cases delete the VM, then delete the VM folder and then re-provision, e.g.

vagrant destroy node02
rmdir "<path-to-vm-folder>\node02
vagrant up

Provisioner gets stuck

This will most likely happen at “Waiting for machine to reboot”

Hit CTRL+C
Kill any running ruby process, or Vagrant will complain.
Destroy the VM that got stuck: vagrant destroy <vm>
Re-provision. It will pick up where it left off: vagrant up

Pausing the Environment

You do not need to complete the entire lab in one session. You may shut down and resume the environment as follows, if you need to power off your computer.

To shut down. This will gracefully shut down all the VMs in the reverse order to which they were started:

vagrant halt

To power on again:

vagrant up

Deleting the Virtual Machines

When you have finished with your cluster and want to reclaim the resources, perform the following steps

Exit from all your VM sessions
Run the following
```
 vagrant destroy -f
```

Next: Connectivity
Prev: Prerequisites