## 1.1.1. Oracle VirtualBox

### 1.1.1.1. Create a NAT Network in VirtualBox
In "Oracle VM VirtualBox Manager", Menu "File > Preferences... > Network", create a NAT 
network with the following specifications:

|Name       |CIDR       |DHCP    |IPv6    |
|-----------|-----------|--------|--------|
|TFS-NAT-Net|10.0.2.0/24|Disabled|Disabled|

Within the newly created "TFS-NAT-Net" NAT network, configure the following IPv4 
forwarding rules:

|Name|Protocol|Host IP  |Host Port|Guest IP |Guest Port|
|----|--------|---------|---------|---------|----------|
|SSH |TCP     |127.0.0.1|2200     |10.0.2.10|22        |
|HTTP|TCP     |127.0.0.1|8080     |10.0.2.10|80        |

__Note__: IP address 10.0.2.10 is the one that will be assigned to the VM.


### 1.1.1.2. Create VM in VirtualBox:

- Name: TFS-VM
- Type/Version: Linux / Ubuntu (64-bit)
- CPU (*): 4 vCPUs @ 100% execution capacity
- RAM: 8 GB
- Disk: 40 GB, Virtual Disk Image (VDI), Dynamically allocated
- Optical Drive ISO Image: "ubuntu-20.04.4-live-server-amd64.iso"
  - Download the file "ubuntu-20.04.4-live-server-amd64.iso" from [Ubuntu 20.04 LTS](https://releases.ubuntu.com/20.04/).
  - __Note__: use Ubuntu Server image instead of Ubuntu Desktop to create a lightweight VM.
- Network Adapter 1 (*): enabled, attached to NAT Network "TFS-NAT-Net"
- Minor adjustments (*):
  - Audio: disabled
  - Boot otder: disable "Floppy"

__Note__: (*) settings to be editing after the VM is created.

### 1.1.1.3. Install Ubuntu 20.04 LTS Operating System
In "Oracle VM VirtualBox Manager", start the VM in normal mode, and follow the 
installation procedure.
Below we provide some installation guidelines:
- Installation Language: English
- Autodetect your keyboard
- Configure static network specifications:

|Interface|IPv4 Method|Subnet     |Address  |Gateway |Name servers   |Search domains|
|---------|-----------|-----------|---------|--------|---------------|--------------|
|enp0s3   |Manual     |10.0.2.0/24|10.0.2.10|10.0.2.1|8.8.8.8,8.8.4.4|<empty>       |

- Leave proxy and mirror addresses as they are
- Let the installer self-upgrade (if asked). At the time of writing this walkthrough, the version of the installer is 22.06.1. Anyway, Ubuntu 20.04 LTS OS will be installed.
- Use an entire disk for the installation
  - Disable setup of the disk as LVM group
  - Double check that NO swap space is allocated in the partition table. Kubernetes does not work properly with SWAP.
- Configure your user and system names:
  - User name: TeraFlowSDN
  - Server's name: tfs-vm
  - Username: tfs
  - Password: tfs123
- Install Open SSH Server
  - Import SSH keys, if any.
- Featured Server Snaps
  - Do not install featured server snaps. It will be done manually later to illustrate how to uninstall and reinstall
    them in case of trouble with.
- Let the system install and upgrade the packages.
  - This operation might take some minutes depending on how old is the Optical Drive ISO image you use and your
    Internet connection speed.
- Restart the VM when the installation is completed.

## 1.1.1.4. Upgrade the Ubuntu distribution
```bash
sudo apt-get update -y
sudo apt-get dist-upgrade -y
```

## 1.1.1.5. Install VirtualBox Guest Additions
On VirtualBox Manager, open the VM main screen. If you are running the VM in headless 
mode, right click over the VM in the VirtualBox Manager window and click "Show".
If a dialog informing about how to leave the interface of the VM is shown, confirm 
pressing "Switch" button. The interface of the VM should appear.

Click menu "Device > Insert Guest Additions CD image..."

On the VM terminal, type:
```bash
sudo apt-get install -y linux-headers-$(uname -r) build-essential dkms
  # This command might take some minutes depending on your VM specs and your Internet access speed.
sudo mount /dev/cdrom /mnt/
cd /mnt/
sudo ./VBoxLinuxAdditions.run
  # This command might take some minutes depending on your VM specs.
sudo reboot
```
