VirtualBox is a great tool often used to simulate an entire lab. It could create all need to accomplish this goal for you.

VirtualBox can create multiples Networks and different virtual machines (VMs). On this post, I will show you how to create a simple lab environment step by step.

On this scenario, I’ll use Virtualbox 6 and two type of networks:

• Nat Network, it is the main network which will be use to communicate with the ouside world and other VMs.
• Host-Only Adapter, this network is only used to get access on the VM from your desktop.

Steps

Installation

You need choose your appropiate package from this URL

For ubuntu users:

sudo apt-get update
sudo apt-get install virtualbox

or

wget https://download.virtualbox.org/virtualbox/6.0.14/virtualbox-6.0_6.0.14-133895~Ubuntu~xenial_amd64.deb
sudo dpgk -i virtualbox-6.0_6.0.14-133895~Ubuntu~xenial_amd64.deb

Consider install the VirtualBox Extension Pack from here

Network Configuration

Host Network

By default, VirtualBox already creates a Host-Only Adapter network, which use this CIDR: 192.168.56.0/24.

This network will be use only to communicate with your Host (a.k.a your desktop machine). Also, on this lab environment we need a Nat Network, whch is another kind of network

If you don’t have this adapter, you need to create it with this simple command

VBoxManage hostonlyif create

Nat Network

A Nat network is the main network which will be use to communicate your VM with with the outside world. Virtualbox creates this network using these steps.

E.g. Create the network 10.0.2.0/24 with name natnet

VBoxManage natnetwork add --netname natnet --network "10.0.2.0/24" --enable --dhcp on
VBoxManage natnetwork start --netname natnet

Virtual Machine Setup

Create a VM base

I need to create a VM to use it as base to create other VM’s. In this example, I will use Centos 7 image, and the VM will named centos7

export VM=centos7

VBoxManage createvm --name $VM --ostype RedHat_64 --register

Now, we need to associate the natnetwork created previously with the nic1 interface

VBoxManage modifyvm $VM --nic1 natnetwork --nat-network1 natnet

Create another nic2 type Host-Only Adapter

VBoxManage modifyvm $VM --nic2 hostonly --hostonlyadapter2 vboxnet0

If you want to increase the CPU and Memory, this moment is good to do that

VBoxManage modifyvm $VM --cpus 2 --memory 512

The VM will need a storage, then create a dynamic disk with 10GB and a SATA Controller to attach it

VBoxManage createhd --filename ~/VirtualBox\ VMs/$VM/$VM.vdi --size 10240
VBoxManage storagectl $VM --name "SATA Controller" --add sata --controller IntelAHCI
VBoxManage storageattach $VM --storagectl "SATA Controller" --port 0 --device 0 \
  --type hdd --medium ~/VirtualBox\ VMs/$VM/$VM.vdi

Create a IDE controller to mount the iso installer image in order to begin the installation process. E.g. I will use the CentOS 7 minimal image iso.

Previously you need to download the iso image

mkdir ~/isos/
wget \
  http://centos.usetelecom.com.br/centos/7.7.1908/isos/x86_64/CentOS-7-x86_64-Minimal-1908.iso 
  -O ~/isos/

VBoxManage storagectl $VM --name "IDE Controller" --add ide
VBoxManage storageattach $VM --storagectl "IDE Controller" --port 0 \
  --device 0 --type dvddrive --medium ~/isos/CentOS-7-x86_64-Minimal-1908.iso

You could setup others miscellaneous system options

VBoxManage modifyvm $VM --ioapic on
VBoxManage modifyvm $VM --boot1 dvd --boot2 disk --boot3 none --boot4 none

And finally, you have a VM created like this:

To start the VM and begin the installation process, use the follow command:

VBoxManage startvm $VM

Install Centos OS

Start the installation process

Setup your localtime. In my case, as I live in Brazil, it is America/Sao_Paulo

Create a ansible user, and make it Administrator

Also, you need to setup the root password

Finished the installation, login into the VM as root user and edit the first one NIC

You need to pay attention on this variables:

BOOTPROTO=static
ONBOOT=yes
IPADDR=10.0.2.2
PREFIX=24
GATEWAY=10.0.2.1
DNS1=10.0.2.1

Edit the second NIC

Pay attention on this variables

BOOTPROTO=static
DEFROUTE=no
ONBOOT=yes
IPADDR=192.168.56.2
PREFIX=24

Restart the system network service and check the network connectivity

systemctl restart network 
ip addr | grep "inet "
ip route

Testing

SSH access to VM from the Host-only Adapter

$ ssh root@192.168.56.2
root@192.168.56.2's password: 
Last login: Tue Oct 15 23:10:05 2019 from 192.168.56.1
[root@localhost ~]# ping www.terra.com
PING www.terra.com (208.70.188.57) 56(84) bytes of data.
64 bytes from www.terra.com (208.70.188.57): icmp_seq=1 ttl=53 time=151 ms
64 bytes from www.terra.com (208.70.188.57): icmp_seq=2 ttl=53 time=151 ms
^C
--- www.terra.com ping statistics ---
3 packets transmitted, 2 received, 33% packet loss, time 2002ms
[root@localhost ~]# 

Final Step

Once you have configured the operating system, you can shutdown and eject the DVD.

$ ssh root@192.168.56.2
root@192.168.56.2's password:
Last login: Tue Oct 15 23:10:05 2019 from 192.168.56.1
[root@localhost ~]# halt -p

VBoxManage storageattach $VM --storagectl "IDE Controller" --port 0 \
  --device 0 --type dvddrive --medium none

Others usefull commands #

Start in headless mode

VBoxManage startvm $VM --type headless

Remove nat network

VBoxManage natnetwork remove --netname natnet

Disable the dhcp

VBoxManage natnetwork modify --netname natnet --dhcp off

Start the nat network

VBoxManage natnetwork start --netname natnet

Take snapshots

VBoxManage snapshot $VM take <name of snapshot>

Revert snapshot

VBoxManage snapshot $VM restore <name of snapshot>

Delete VM

VBoxManage unregistervm $VM --delete

Sources #

https://www.oracle.com/technical-resources/articles/it-infrastructure/admin-manage-vbox-cli.html

https://www.virtualbox.org/manual/ch08.html

https://www.perkin.org.uk/posts/create-virtualbox-vm-from-the-command-line.html

https://www.nakivo.com/blog/virtualbox-network-setting-guide/

https://www.virtualbox.org/manual/ch06.html

https://www.linuxtechi.com/manage-virtualbox-virtual-machines-command-line/