In this post we install and configure an instance of Ubuntu Server under WSL2 for Linux. Many developers are going to choose to use WSL2, so we guide them to install the Ubuntu Server version of WSL2. This provides a more standard environment referenced by many howto procedures on the Internet.
WSL2 enables a computer running Windows 11 Pro to host a guest instance of Ubuntu Server:
WSL2 offers some advantages for a developer experience
WSL2 offers some advantages for a local developer in terms of networking: if they install a service that opens a port, like port 22/tcp for SSH, that same port is opened on localhost of the Windows machine hosting the WSL2 Ubuntu Server instance. A developer can SSH to port 22 on localhost, without configuring a static IP address or port forwarding. This eliminates the need to configure virtual switches, static IP addresses, and port forwarding. In addition, WSL2 provides a file mounts of the Windows file system within Linux, and a file mount of the Linux filesystem within Windows.
Other ways to install Ubuntu Server on a Windows 11 Pro computer
There are other ways to install Ubuntu Server on a Windows 11 Pro computer, including Windows Hyper-V. If you need to host multiple instances of Ubuntu Server with static IP addresses and subnet routing, consider using Hyper-V instead.
Installing WSL2
Start a CMD window as Administrator. At the Start menu, type the letters “cmd” then right-click on the app icon to run the command prompt as root:
Enter the following command:
powershell
Enter the following command:
wsl --install -d Ubuntu-24.04
Reboot your computer.
Enter values for username and password:
Enter the following command from a CMD window running as Administrator:
wsl --list --verbose
Enter the following command:
wsl --setdefault Ubuntu-24.04
Enter the following command:
wsl
Enter the following command:
lsb_release -a
Enter the following command:
sudo su
Updating apt packages on the Linux system
Enter the following commands:
apt clean
apt update
Enter the following command:
apt upgrade
Enter y for yes:
Enter the following command:
reboot
from a CMD window running as Administrator, enter the following command:
wsl
Installing some utilities
Enter the following commands:
sudo su
apt install net-tools git build-essential
Installing openssh-server
Enter the following command:
apt install openssh-server
From a CMD window running as Administrator, enter the following command:
In this post, we build a home server using Ubuntu Desktop Linux that includes a Samba network file server, an OpenVPN virtual private network (VPN), and a KVM hypervisor hosting virtual machine (VM) guests including a Linux/Apache/MySQL/PHP web server. In addition, we build an offsite backup server using Fedora Server Linux, and link the offsite backup server to the home server via a WireGuard secure network tunnel.
Tasks for the home server
The home server will perform the following tasks:
Samba network file server
OpenVPN server
KVM hypervisor to host virtual machine (VM) guests
LAMP web server in a VM
Wireguard public-facing host to client connection to offsite backup server
Hardware for the home server
As the home server will host virtual machine guests, I need a certain level of performance, so I bought a refurbished circa 2017 computer for C$403 (US$294). CPU performance can affect OpenVPN performance, so the VPN server will benefit from a stronger CPU as well.
The home server is a small form factor (SFF) desktop circa 2017:
Dell OptiPlex 5050 SFF (circa 2017)
i7-7700 CPU
32GB DDR4 RAM
1TB SATA SSD
Formatting and configuring the home server with Ubuntu Desktop 22.04 LTS
I formatted the home server with Ubuntu Desktop 22.04 LTS.
Why choose Ubuntu Desktop instead of Ubuntu Server?
For the home server, I wanted the option of a graphical user interface (GUI) desktop for use at console, and via remote desktop. A GUI desktop is also more convenient for the creation and management of KVM virtual machine guests using the virt-manager GUI, (and avoids the need for SSH tunnel forwarding and an X11 server to reach a headless server).
Formatting in UEFI mode
With modern hardware, I like to use UEFI mode for disk booting. Although we do not need a multiple-boot menu for this server, it is easier to construct a multiple-boot menu using grub when booting in UEFI mode. This is the default on a post-2016 motherboard, but it is worth looking at the BIOS when you first lay hands on a machine.
Connecting using wired Ethernet
We need a wired Ethernet connection for the home server, as we want to create a bridge mode adapter (br0) so that virtual machine (VM) guests can have IP addresses in the host networking subnet.
Complete the fields as needed, then click on “Continue”:
Click on “Restart Now”:
Press the ENTER key on your keyboard:
Using the nmcli command to create a bridge mode adapter (br0)
Because we are working on an Ubuntu desktop, we will use the nmcli command to create a bridge mode adapter (br0).
Open a terminal window. Enter the following commands:
sudo su
apt install net-tools bridge-utils
ifconfig
Look at the information displayed by the ifconfig command. Identify the name of the wired Ethernet connection. The name may be “eth0” or a string such as “enp0s31f6”
Use the value you identified above and use it in place of ethernet_name.
Enter the following commands:
nmcli con add ifname br0 type bridge con-name br0
nmcli con add type ethernet ifname ethernet_name master br0
nmcli con up br0
nmcli con show
brctl show
Using the nmcli command to set a static IP address on the bridge mode adapter (br0)
Although the br0 adapter appears in the Gnome Settings control panel, its IP address cannot be set using this graphical user interface (GUI). We can set the IP address and other IPV4 values of a br0 adapter using the nmcli command.
Enter the following commands:
nmcli con modify br0 ipv4.addresses 192.168.56.40/24 ipv4.gateway 192.168.56.1 ipv4.method manual
nmcli con modify br0 ipv4.dns "8.8.8.8 8.8.4.4"
nmcli con down br0 && sudo nmcli con up br0
con show br0
Understanding the bridge networking device (br0) and its relationship with the Ethernet adapter
The bridge networking device (br0) is a wrapper around the Ethernet adapter. The br0 adapter replaces the Ethernet adapter.
Configuring the desktop user to login automatically
From the Ubuntu Desktop, Start the Settings application. Click on the search icon and search for “users”:
Click on “Unlock…”:
When prompted, enter the password for the user that owns the desktop session:
Enable “Automatic Login”:
Setting Blank Screen Delay to Never and Disabling Automatic Screen Lock
In the Settings application, go to Privacy, then Screen. Change “Blank Screen Delay” to “Never”. Disable “Automatic Screen Lock”:
Enabling Remote Desktop Sharing
In the Settings application, go to Sharing, then go to “Remote Desktop”. Enable “Remote Desktop”. Enable “Remote Control”. Provide values for “User Name” and “Password”
Creating a firewall exception for the remote desktop port
Open a terminal window. Enter the following commands:
sudo su
ufw allow 3389/tcp
Testing Remote Desktop access to the home server from a Linux desktop
Use the Remmina program and select the RDP protocol. Complete the fields as necessary for your installation, then click on “Save and Connect”:
Testing Remote Desktop Sharing from a Windows 11 Pro desktop
Click on the Start button. Enter the text “remote desktop”. Click on the icon for “Remote Desktop Connection”:
Enter the IP address of the home server. Click “Connect”:
Enter the username and password you specified in the Settings application on the home server under Sharing | Remote Desktop:
Check the box “Don’t ask me again for connection to this computer”. Click on “Yes”:
Considering VNC as an alternative to Remote Desktop (RDP)
If you have difficulty connecting to the home server using a Windows remote desktop client, consider using VNC:
Using the smbpasswd command to create a Samba username to match the desktop username
Open a terminal window. Enter the following commands. Replace username with the user that owns the desktop on the home server. When prompted, provide a value for the password:
sudo su
smbpasswd -a username
Creating a firewall exception for the network file sharing (CIFS) port
Enter the following command:
ufw allow 137,138,139,445/tcp
Testing the network file share using the Files (Nautilus) program
In the Files (Nautilus) application, click on “+ Other Locations”:
Select “Registered User”. Provide a value for “Username”. For Domain, put “WORKGROUP”. Provide a value for “Password”. Click on “Connect”:
Testing the network file share using File Explorer in Windows 11 Pro
From the File Explorer application in Windows 11 Pro, enter the address of the server in the address bar. Prefix the address with “\\” as in “\\192.168.56.40” for the following example. Enter the IP address of your home server:
Advanced applications of Samba including Active Directory authentication
Declaring a CNAME record in DNS to map a subdomain to the IP address of the persistent host name
If you have a registered domain name, and you have access to the DNS control panel for that domain, you can declare a CNAME record in DNS to map a subdomain to the ip address of the persistent hostname. For example, the GoDaddy DNS control panel allows the following kind of CNAME declaration:
This creates the subdomain servername.example.com, which will ping to the same IP address as persistenthostname.ddns.net
In this case we have set the time-to-live (TTL) value to 1 hour, so the IP address of the CNAME host would be updated once per hour. Many DNS providers block the option of declaring a CNAME to the apex (@) host of a domain. You can still host a subdomain, for example:
https://servername.example.com
If you need to declare the @ host as a CNAME consider pobox.com
If you need to declare the @ host of a domain as a CNAME associated with a persistent host name, consider using pobox.com as your DNS provider.
Using a script to automate the installation of OpenVPN
The openvpn-install.sh from Nyr automates the installation of the OpenVPN server application:
From the desktop of the home server, open a terminal window. Enter the following commands:
virt-manager
Verifying that the virtual machine (VM) is set for bridge mode with the br0 device
Click on the “i” icon on the VM. Select “NIC”:
Determining the current IP address of the VM
Enter the following commands:
sudo su
apt install net-tools
ifconfig
Note the name (ie enp1so) and IP address of the first adapter:
Connecting to the server with SSH
Open a terminal window on the desktop of the home server. Enter the following command, substituting values for username and ipaddress to match your installation:
ssh username@ipaddress
Creating a netplan for a static IP address for the VM
As the VM is running Ubuntu Server, we will use netplan to create a static IP address.
From the SSH terminal window, enter the following commands:
sudo su
cd /etc/netplan
cp 00-installer-config.yaml 00-installer-config.yaml.b4
nano 00-installer-config.yaml
Use the nano text editor to modify the 00-installer-config.yaml file. Change the value of adaptername as needed ie “enp1s0”:
Use the nano text editor to modify the apache2.conf file. Find the “<Directory /var/www/>” section. Change “AlllowOverride None” to “AllowOverride All”:
<Directory /var/www/html>
Options Indexes FollowSymLinks
AllowOverride All
Require all granted
</Directory>
Enter the following commands:
a2enmod rewrite
systemctl restart apache2
Running the mysql_secure_installation command
Enter the following command.
mysql_secure_installation
Answer the prompts as follows:
Testing the web server on port 80
From the desktop of the home server, start a web browser. Visit the IP address of the VM that hosts the LAMP web server:
Forwarding the LAMP web server ports from the public-facing router to the bridge mode IP address of the VM hosting the LAMP web server
Testing the web server from a public address
Using your cell phone: switch to LTE data mode. Visit the URL of your persistent hostname. If you have a CNAME declared for a subdomain host in DNS, visit that URL as well.
Creating virtual hosts for Apache
Open an SSH terminal window to the VM hosting the LAMP web server:
ssh desktop@192.168.56.23
Enter the following commands:
sudo su
cd /etc/apache2/sites-available
nano persistenthostname.ddns.net.conf
Use the nano text editor to edit the persistenthostname.ddns.net.conf file:
Using Let’s Encrypt to create an SSL certificate for https
Open an SSH terminal window to the VM hosting the LAMP web server. Enter the following commands:
sudo su
apt install python3-certbot-apache
certbot --apache
systemctl restart apache2
Enabling Wireguard on the home server
Open an SSH terminal window to the home server. Provide values for username and ipaddress to match your installation:
ssh username@ipadress
Creating public and private WireGuard keys
Enter the following commands:
sudo su
cd /etc/wireguard
umask 077
wg genkey > privatekey
wg pubkey < privatekey > publickey
Creating a firewall exception for the WireGuard port on the home server
ufw allow 55555/udp
Enter the following commands:
nano wg0.conf
Creating the wg0.conf file
Use the nano text editor to modify the wg0.conf file. Provide a value for privatekey matching the privatekey of the home server, generated above. (Provide a value for publickey of the peer system (the offsite backup server) when the value becomes available, then restart the wg-quick@wg0 service):
[Interface]
# home server
Address = 10.5.0.1/24
PrivateKey = privatekeyofhomeserver
ListenPort = 55555
[Peer]
# offsite backup server
PublicKey = publickeyofoffsitebackupserver
AllowedIPs = 10.5.0.0/24, 192.168.1.0/24
Forwarding the WireGuard port from the public-facing router to the home server
Tasks for the offsite backup server
The offsite backup server will perform the following tasks
Samba network file server
Wireguard client connection to home server
Hardware for the backup server
My brother donated a computer to the project, a computer that was headed for a dumpster. This is an example of a hacker living his principles.
This machine could not address more than 1.5GB RAM of the RAM we found in our junkpiles. This machine has a 20GB mechanical hard drive — we could certainly upgrade that with a 120GB SSD, but we decided to see what was possible with the mechanical drive. We will be attaching an SSD drive to the computer. Because the taskings are Samba network file sharing and a Wiregurd tunnel to the home server, it may not be necessary to upgrade the mechanical drive.
The offsite backup server is a small form factor (SFF) desktop circa 2005:
HP HSTNC-008P-SF (circa 2005)
Pentium(R) D CPU
1.5GB DDR RAM
20GB mechanical drive (presumably 5400RPM)
Formatting and configuring the offsite backup server with Fedora Server 38
My brother formatted the offsite backup server with Fedora Server 38. This server will have a text-only console. This will allow us to conserve about 1.1GB RAM, ie 3/4 of the 1.5GB RAM we have available in the system.
Why choose Fedora Server instead of Fedora Desktop?
For the offsite backup server, as the hardware is limited, we will use Fedora Server to conserve CPU and RAM resources.
Formatting in Legacy Mode
With older, pre-2016 hardware, it is simpler to format in Legacy Mode. In this case, the system literally is legacy, this is the only mode available.
Connecting using wired Ethernet
We will connect the offsite backup server using wired Ethernet. This simplifies some kinds of networking, including WireGuard, which we will use later in this procedure to create a secure tunnel to the home server.
Installing a few utilities on the offsite backup server
Log in at the console of the offsite backup server. Enter the following commands:
sudo su
dnf install net-tools iptraf-ng finger wireguard
ifconfig
Examine the output of the ifconfig command. Find the name of the Ethernet adapter, it may be something like “enp0s25” or “eth0” — take note of this value.
Using the nmcli command to configure a static IP address for the offsite backup server
Enter the following commands. Provide values for adaptername and ipv4.gateway that match your installation:
nmcli con modify adaptername ipv4.addresses 192.168.1.95/24 ipv4.gateway 192.168.1.1 ipv4.method manual
nmcli con modify br0 ipv4.dns "8.8.8.8 8.8.4.4"
nmcli con down br0 && sudo nmcli con up br0
con show br0
reboot
Installing the Samba program on the offsite backup server
Open an SSH terminal window to the offsite backup server. Enter the following command:
dnf install samba
Creating a network file share using Samba on the offsite backup server
Use the nano text editor to modify the wg0.conf file. Provide a value for privatekey matching the privatekey of the home server, generated above. Provide a value for publickey matching the private key of the offsite backup server:
In this procedure we install the open source program OpenVPN on a server running on Linux to create a virtual private network (VPN) authenticated against Active Directory with two-factor authentication (2FA) enabled Google Authenticator.
Business case
A Linux server running OpenVPN server software can replace a Windows server or other commercial solution for the VPN server role in the enterprise, reducing software licensing costs and improving security and stability.
Authenticating connections to the VPN server using client certificates and Google Authenticator one-time passwords (OTPs)
Verifying client-side VPN certificates to authenticate a VPN connection
The VPN server will verify client digital certificates as one of the authentication methods.
Using Google Authenticator to obtain a one-time password (OTP) to authenticate a VPN connection
The VPN server will verify the one-time password (OTP) generated by Google Authenticator as one of the authentication methods.
Entering the OTP from Google Authenticator as the password for the VPN connection
To access the network, help desk clients will:
Enter their local network file share or Active Directory username as the username for the VPN connection.
Enter the OTP from Google Authenticator as the password for the VPN connection.
Not verifying a local password authentication module (PAM) or Active Directory password to authenticate a VPN connection
This procedure does not verify a PAM or Active Directory password to authenticate the VPN connection.
There are ways of prompting for a username, and a password, and an OTP from Google Authenticator. However, some of these are difficult to integrate with with client VPN connector software, which do not support a second password field. Some approaches ask the help desk client to enter a system password and the OTP as a combined password, but this can be confusing for help desk clients.
This procedure was tested on Ubuntu Linux 22.04 LTS
Deploying the VPN server as a physical or virtual machine
Deploy OpenVPN on a physical Linux server or on a virtual Linux server hosted as a virtual machine (VM), using KVM on Linux, Hyper-V, VMware, or VirtualBox on Windows, or Parallels using MacOS.
Adding a macvtap or bridge mode network adapter to a virtual machine
For KVM, add a macvtap network adapter to the automation server. For Hyper-V, VMware, VirtualBox or Parallels, add a bridge mode network adapter. This will allow the VPN server to access the same network as the server’s hypervisor host.
Assigning a static IP address to the server that will host the VPN
Assign a static IP to the VPN server.
Assigning a permanent host name to a dynamic host configuration protocol (DHCP) public-facing IP address
Most residential Internet connections have a dynamic host configuration protocol (DHCP) public-facing IP address, which can change over time. You can use a service like no-ip.com to associate a permanent host name such as permhostname.ddns.net to a host with a dynamic IP address:
cd /etc/openvpn/server
nano google-authenticator.sh
#!/usr/bin/bash
# this script written by OpenAI ChatGPT
# see References section for prompt
# check if the user has provided a username and password
if [ -z "$username" -o -z "$password" ]; then
exit 1
fi
# get the user's secret key from the Google Authenticator app
secret_key=$(grep "^$username:" /etc/openvpn/server/google-authenticator.keys | cut -d: -f2)
# check if the user has a secret key
if [ -z "$secret_key" ]; then
exit 1
fi
# generate a six-digit code using the secret key and the current time
code=$(oathtool --totp -b "$secret_key")
# compare the generated code with the password provided by the user
if [ "$code" = "$password" ]; then
exit 0
else
exit 1
fi
Press Ctrl-X to save and exit the file.
Enter the following command:
chmod 755 google-authenticator.sh
Restarting the OpenVPN server
From a root shell, enter the following command:
systemctl restart openvpn-server@server
Downloading the OpenVPN client profile
Use the FileZilla file transfer client to download the OpenVPN client profile:
Use a text editor to load the OpenVPN client profile. Add the following text to the bottom of the file:
auth-user-pass
Save and exit the file.
Downloading and Installing the Google Authenticator app on a help desk client’s smartphone
Visit the Apple App Store or the Google Play Store. Search for “google authenticator” and download the app:
Click on “Get started”:
Running the google-authenticator command on the server to enrol the help desk client’s Google Authenticator app
Open a terminal window as root, and make the terminal window full-screen. Enter the following command:
google-authenticator
Scanning the QR code into the Google Authenticator smartphone app
Click on “Scan a QR code” then click on “OK” to allow the app to access the camera:
Look at the one-time code shown on the Google Authenticator app:
Enter the code in the Terminal window in the field: “Enter code from the app (-1 to skip):”
Enter “n” to the question: “Do you want me to update your “/root/.google_authenticator file? (y/n):”
Creating the /etc/openvpn/server/google-authenticator.keys file and entering the secret key created during enrolment of the help desk client’s Google Authenticator app.
Enter the following commands:
cd /etc/openvpn/server nano google-authenticator.keys
Add an entry to the file in with the format “username: yournewsecretkey”:
client06a:NRX7VMDMIC6XSDFJNU3WVB3K2I
Press Ctrl-X to save and exit the file.
A note re automation
Should this process be automated further? Yes. The google-authenticator program on the server could be scripted so that the client’s username and secret code could be added to the /etc/openvpn/server/google-authenticator.keys file.
In this post, we use the server automation tools Ansible, Terraform, Docker, and Kubernetes to create and configure virtual machines (VMs) to host an on-premises Kubernetes cluster.
Understanding infrastructure
Infrastructure refers to computing resources used to store, transform, and exchange data. A new approach to software development called DevOps deploys applications across distributed systems consisting of multiple physical and virtual machines.
Understanding DevOps
DevOps is an approach to software development and system administration that views system administration as a task to be automated, so that software developers are not dependent on the services of a system administrator when they deploy software to server infrastructure.
DevOps tools automate the creation and deployment of servers to create a distributed software infrastructure on which software can be deployed and run on multiple computers whether physical or virtual.
Understanding the difference between cloud and on-premises (“onprem”) virtualization servers
The term “cloud” refers to computing services that are offsite, outsourced, and virtualized. These cloud services are provided by companies including Amazon AWS, Google GCP, Microsoft Azure, and Digital Ocean.
The term “On-premises” (“onprem”) refers to computing services that are onsite, in-house, and virtualized. Onprem virtualization servers can provide the same software environment as cloud providers. Onprem server infrastructure can be used to develop and test new software before it is deployed to a public cloud.
Overview of the system to be constructed
Understanding the virtualization server
Virtual machines require a physical machine containing processors, memory, and storage. For this exercise, we will reformat a circa 2015 laptop (i7-4712HQ, 16GB RAM, 1TB SSD) with Ubuntu Linux 22.04 LTS as an on-premises virtualization host.
Understanding KVM virtualization
KVM creates a hypervisor virtualization host on a Linux server. A KVM hypervisor can host multiple virtual machine (VM) guests.
Understanding Terraform
Terraform can run scripts that automate the creation of virtual machines, on public clouds such as Amazon AWS, Google GCP, and Digital Ocean, as well as on on-premises (“onprem”) virtualization hosts including KVM.
Understanding the libvirt provider software
The libvirt provider software enables Terraform to automate the creation of virtual machines on KVM hypervisor hosts.
Understanding Ansible
Ansible can run scripts that automate server administration tasks. In this exercise, multiple Ansible scripts will be executed to use Terraform to create virtual machine (VM) servers, on which software will be deployed and configured, creating a Kubernetes cluster.
Understanding virtual machine (VM) guests
A virtual machine (VM) guest is a server that emulates hardware as a software image, using a subset of the hypervisor host’s processor cores, memory, and storage to create a distinct computer environment, with its own software libraries, network address, and password or key entry system.
Understanding Docker software containers
Docker containers are software containers created by the docker-compose command. A Docker container has its own software libraries, network address, and password or key entry system, but comparisons between Docker containers and virtual machines (VMs) are discouraged.
Understanding Kubernetes
Kubernetes is software that allows you to create a high-availability cluster consisting of a control plane server and one or more worker servers. Kubernetes allows for software to be deployed as containers stored in pods, running on clusters, running on nodes.
Containers
Software is organized within Docker containers. A Docker container is a self-contained computing environment with its own libraries, IP address, and SSH password or key.
Pods
Pods are a unit of computing that contain one or more containers. Pods execute on clusters, which are intermediate interfaces that distribute computing tasks across control plane and worker nodes, running on virtual machine servers.
Clusters
A cluster is an addressable interface that allows for the execution of Kubernetes Pods across a distributed system of control plane and worker nodes.
Nodes
In Kubernetes, a node is the physical or virtual machine that hosts the control plane role or worker role in a distributed Kubernetes cluster. In this exercise the nodes will be hosted on KVM virtual machines (VMs).
Understanding the automation server
The automation server is a Linux server separate from the virtualization server. The automation server can be a physical or virtual machine.
Tip: avoid running operations like this from your baremetal desktop. These operations involve hosts files and SSH keys for server access, and should be isolated if possible. Consider creating a virtual machine for this role using a hypervisor such as KVM on Linux, VirtualBox on Windows, or Parallels on MacOS. Use Ubuntu Linux 22.04 LTS.
Entering commands as root
This procedure assumes that you are entering commands as root. Escalate to the root user:
sudo su
Preparing the virtualization server 1/3
The virtualization server should be a minimal build: do a fresh format of Ubuntu Linux 22.04 LTS.
Using a wired network connection
If possible, use a wired Ethernet connection for the network connection on the hypervisor. This simplifies advanced operations like iptables forwarding and makes possible the later use of macvtap adapters for connecting in the hypervisor host networking space.
Setting a static IP address
Set a static IP address for the network connection of the virtualization server. Reboot.
Installing software on the virtualization server
From a root shell on the virtualization server, enter the following command:
Configuring the SSH server on the virtualization server
From a root shell on the virtualization server, enter the following commands:
cd /etc/ssh
Use the nano editor to create the following text file:
nano sshd_config
uncomment and replace the following line:
PermitRootLogin yes
Creating a root password
sudo su
passwd
Preparing the automation server 1/2
Configure a virtual machine on a different physical machine than the virtualization server. Use Ubuntu Linux 22.04 LTS.
Adding a macvtap or bridge mode network adapter
For KVM, add a macvtap network adapter to the automation server. For VirtualBox or Parallels, add a bridge mode network adapter. This will allow the automation server to access internal subnets on the virtualization server via an ip route command.
Installing software and downloading Ansible scripts on the automation server
From a root shell on the automation server, enter the following commands:
apt install ansible git openssh-server net-tools iptraf-ng
cd /root
mkdir tmpops
cd tmpops
git clone https://github.com/kubealex/libvirt-k8s-provisioner.git
Creating the Ansible hosts file
cd /etc
mkdir ansible
cd ansible
Use the nano editor to create the following text file (use the IP address of the virtualization server in your setup):
nano hosts
contents:
[vm_host]
192.168.56.60
Creating an SSH key pair
From a root shell on the automation server, enter the following command:
ssh-keygen -f /root/.ssh/id_rsa -q -N ""
When prompted for a passphrase, press Enter and provide a blank value.
Copying the SSH public key to the virtualization server
From a root shell on the automation server, enter the following commands (substitute the IP address of the virtualization server in your setup):
cd /root/.ssh
rsync -e ssh -raz id_rsa.pub root@192.168.56.60:/root/.ssh/authorized_keys
Preparing the virtualization server 2/3
Verifying the automation server’s public key on the virtualization server
From a root shell on the virtualization server, enter the following commands:
Testing that the automation server can connect to the virtualization server using a public SSH key
From the automation server, enter the folowing command (substitute the IP address of your virtualization server):
ssh root@192.168.56.60
Note: If you are able to login without supplying a password, you have succeeded.
Using Ansible to automate operations
Ansible can run scripts called playbooks to perform automated server administration tasks. Ansible playbook scripts will use Terraform to create and configure virtual machines (VMs) on which a Kubernetes cluster will be installed.
A note about the libvirt-k8s-provisioner project
The libvirt-k8s-provisioner project provides a set of scripts that use Ansible and Terraform to create virtual machines (VMs) and to deploy a Kubernetes cluster.
Modifying the libvirt-k8s-provisioner vars file
cd /root/tmpops/libvirt-k8s-provisioner/vars
nano k8s_cluster.yml
Installing the collection requirements for Ansible operations
From a root shell on the virtualization server, enter the following commands:
cd /root/tmpops/libvirt-k8s-provisioner
ansible-galaxy collection install -r requirements.yml
Running the Ansible playbook to create and configure virtual machines on the virtualization host 1/2
From a root shell on the virtualization server, enter the following commands:
ansible-playbook main.yml
The task sequence will end with this error:
fatal: [k8s-test-worker-0.k8s.test]: FAILED! => {"changed": false, "elapsed": 600, "msg": "timed out waiting for ping module test: Failed to connect to the host via ssh: ssh: Could not resolve hostname k8s-test-worker-0.k8s.test: Name or service not known"}
fatal: [k8s-test-master-0.k8s.test]: FAILED! => {"changed": false, "elapsed": 600, "msg": "timed out waiting for ping module test: Failed to connect to the host via ssh: ssh: Could not resolve hostname k8s-test-master-0.k8s.test: Name or service not known"}
Note: we will recover from this error in a later step.
Preparing the virtualization server 3/3
From a root shell on the virtualization server, enter the following command:
virsh net-dhcp-leases k8s-test
Information about the virtual machines in the k8s-test network will be displayed:
root@henderson:/home/desktop# virsh net-dhcp-leases k8s-test
Expiry Time MAC address Protocol IP address Hostname Client ID or DUID
--------------------------------------------------------------------------------------------------------------------------------------------------------
2022-07-29 07:21:42 52:54:00:4a:20:99 ipv4 192.168.200.99/24 k8s-test-master-0 ff:b5:5e:67:ff:00:02:00:00:ab:11:28:1f:a1:fb:24:5c:f5:70
2022-07-29 07:21:42 52:54:00:86:29:8f ipv4 192.168.200.28/24 k8s-test-worker-0 ff:b5:5e:67:ff:00:02:00:00:ab:11:9e:22:e1:40:72:21:cf:9d
Take note of the IP addresses starting with 192.168.200, these values will be needed in a later configuration step.
Understanding the need for IP forwarding on the virtualization server
By default, virtual machines are created with IP addresses in the 192.168.200.x subnet. This subnet is accessible within the virtualization server.
In order to make the 192.168.200.x subnet accessible to the automation server, we need to create a gateway router using iptables directives on the virtualization server.
In a later step, we will add a default route for the 192.168.200.x subnet on the automation server, allowing it to resolve IP addresses in that subnet.
Enabling IP forwarding for the 192.168.200.x subnet
From a root shell on the virtualization server, enter the following commands:
Use the nano editor to create the following text file:
cd /etc
nano sysctl.conf
Add the following line to the end of the sysctl.conf file:
net.ipv4.ip_forward = 1
Enter this command:
sysctl -p
Use the nano editor to create the following text file (substitute the wanadaptername and wanadapterip for those of the virtualization server in your setup):
From a root shell on the automation server, enter the following command (substitute the wanadaptername (dev) and wanadapterip for those of the virtualization server in your setup):
ip route add 192.168.200.0/24 via 192.168.56.60 dev enp0s3
Note: add invocation to /etc/rc.local for persistence.
Testing the IP routing from the automation server to the 192.168.200.x subnet
Ping one of the IP addresses you observed in the preceding step “Preparing the virtualization server 3/3” (Substitute one of the IP addresses in your setup):
ping 192.168.200.99
Running the Ansible playbook to create and configure virtual machines on the virtualization host 2/2
From a root shell on the automation server, enter the following commands:
cd /root/tmpops/libvirt-k8s-provisioner
ansible-playbook main.yml
Verifying that the Ansible task sequence has completed without errors
In this procedure we create a network file share by integrating the open source program Samba running on Linux with Active Directory to authenticate access to the network file share.
Business case
A computer running Linux and Samba can create a network file share authenticating against a company’s Active Directory. This means that a Linux server and Samba network file share software can replace a Windows server for the network file share role in the enterprise, reducing software licensing costs and improving security and stability.
This procedure was tested on Ubuntu Linux 22.04 LTS
This procedure was tested on a network of 3 virtual machines, each running in bridge mode, on different hypervisor hosts.
sudbury
Windows Server 2019 acting as Active Directory controller for the clarkcounty.gordonbuchan.com domain.
sandiego
Ubuntu Linux 22.04LTS desktop joined to the clarkcounty.gordonbuchan.com domain, authenticating access to a network file share enabled by Samba and Winbind against the Active Directory controller for the domain clarkcounty.gordonbuchan.com on sudbury.
hamilton
Windows 10 Pro workstation joined to the clarkcounty.gordonbuchan.com domain.
Understanding Active Directory
Active Directory is commercial software developed by Microsoft that runs primarily on Windows Server. Active Directory can authenticate users and groups of users, and can control access to resources like network file shares and “Single Sign-On” (SSO) login to computers connected to the network.
Understanding Samba
Samba is open source free software that enables a Linux server to provide a network file share that can be accessed by Windows computers.
A note re Samba’s included Active Directory functionality
Samba itself is able to act as an Active Directory controller and can implement a subset of Active Directory’s features. This post assumes that you are authenticating against an Active Directory controller running on Windows Server.
Understanding Winbind
Winbind is software that enables Samba to integrate with Active Directory to authenticate access to a network file share.
Understanding System Security Services Daemon (SSSD)
SSSD is a technology that enables Active Directory integration for Linux workstations. In practice, it is difficult to integrate SSSD with Samba for Active Directory authentication in a stable fashion. There are some approaches to SSSD which incorporate Winbind for a hybrid approach. This procedure will focus on using Winbind, and without using SSSD.
Choosing Winbind over SSSD for a network file share authenticaticated against Active Directory
This procedure will use Winbind to enable Samba to integrate with Active Directory to create a network file share authenticated against Active Directory.
Objectives
Access to the network file share authenticated against Active Directory.
The network file share must be accessible to workstations with “Enable insecure guest logins” set to “Disabled.”
The network file share must observe ACL and allow overrides by Windows clients for ownership and permissions.
(Single-Sign-On (SSO) and SSSD will be addressed in a later procedure.)
Creating the Active Directory group example_group and adding members to the group
Entering commands as root
This procedure assumes that you are logged in as the root user of the Linux server.
Escalate to the root user:
sudo su
Replacing the example realm/domain name with your realm/domain name
Please replace the sample realm/domain name clarkcounty.gordonbuchan.com with your realm/domain name.
Note: for the files /etc/krb5.conf and /etc/samba/smb.conf, the realm/domain name must be in UPPERCASE letters
The realm/domain name must be in UPPERCASE letters. This includes the long version CLARKCOUNTY.GORDONBUCHAN.COM and short version CLARKCOUNTY of the realm/domain name.
Web presence step by step is a series of posts that show you to how to build a web presence.
This post describes how to install Linux as a virtual machine (VM) guest on a Windows computer, by installing a program called VirtualBox.
Installing Linux as a VM guest allows you to explore Linux as a desktop or server operating system from an existing Windows computer, without reformatting.
VirtualBox is a hypervisor
The software that enables a computer to host a virtual machine as a guest is called a hypervisor. The hypervisor we will install in this blog post is called VirtualBox, an open source application available free of charge.
Using a virtual machine (VM) guest as a web, database, or file sharing server for local development and testing
A VM guest performs well in server roles likes web, database, and file sharing. VMs can be used for offline development and testing of websites and web-based applications, which are later deployed to public-facing web servers.
A VM guest can be used to deploy an internal or public-facing server with an application such as WordPress or Nextcloud.
Should you use a VirtualBox VM guest server for production?
Probably not. VirtualBox is great for testing, experiments, learning. However, if you are going into production, to run an essential task for a business, you should consider a more formal deployment using a platform like Linux KVM or Windows Server Hyper-V for an internal deployment, or to a public cloud like Digital Ocean or AWS for a public-facing deployment.
Who should consider using a VirtualBox VM guest server?
VirtualBox enables people to experiment with Linux, without making a commitment to modifying their existing Windows computer.
VirtualBox is great for students — anyone learning software development can host their own fully-functioning Linux server, allowing them to build prototype servers, containers, and software development environments.
Using a VM guest as a graphical user interface (GUI) desktop
A VM guest can function as a graphical desktop, allowing you to use the guest operating system in a sized window, or in full-screen mode. For example, you can connect to another network via VPN from a VM guest, while the host computer running Windows remains connected to its original network.
Limitations of a VM guest GUI desktop
VMs have some limitations: they are not well-suited to GPU-intensive tasks like video editing software or gaming, for example. YouTube video will be choppy.
Installing Ubuntu desktop Linux as a guest VM under VirtualBox
Adjusting resolution
Adjusting window size
Switching to full screen mode
Enabling audio
Network considerations at the hypervisor level
Understanding communications between the host and the VM guest
The VM guest running under VirtualBox is a distinct and separate computer from the machine that hosts it. VirtualBox enables network communication between the VM guest and the Internet, via the network connection of the host.
VirtualBox also enables network communication between the VM guest and the host. For example, if you have a web server running on your VM guest, you can connect to it from your host’s desktop using a web browser or a terminal program like KiTTY for SSH.
Understanding the difference between network address translation (NAT) mode vs bridge mode
Network address translation (NAT) mode
By default, a VM guest is created with a network adapter configured to connect to the Internet via the Internet connection of its host.
A host can communicate with a VM guest via a NAT mode network connection
The host and the VM guest are able to communicate with each other. Computers other than the host cannot see or initiate a network connection with the VM guest.
Creating a NAT network to permit communications between the host and the VM guest
Making a VM guest visible and accessible to other computers on the network to which the host is connected
A VM guest can be made visible and accessible to other computers on the network via a bridge mode network connection, or via port forwarding.
Bridge mode
The network adapter for a VM guest can be configured in “bridge mode” which permits the VM to connect directly to the same network as the host. In this mode, a VM guest can request an IP address or use an IP address in the same subnet as the host and other computers connected to the same network.
A host cannot communicate with a VM guest via a bridge mode network connection
Due to the way that a bridge mode connection is configured to use the network connection of the host, the link permits communication between the VM guest and the outside world, but not between the VM guest and the host itself.
Adding an additional network adapter
(Note: the VM must be powered down in order to add a network adapter.)
Understanding port forwarding
VirtualBox will offer to open a hole on the host’s firewall. Click on “Allow access”:
After upgrading from Ubuntu 20.10 to Ubuntu 21.04, screen sharing (VNC server) is no longer functioning correctly.
Update 2023/11/02: on Ubuntu 22.04, in some situations, the x11vnc server will start on port 5901/tcp, rather than the default 5900/tcp, even if legacy VNC support is disabled.
x11vnc is an effective replacement for Vino and gnome-remote-desktop
This post describes how to install x11vnc, and describes how to create a script that runs at Gnome desktop login that invokes x11vnc with the necessary command line options.
Vino was replaced by gnome-remote-desktop, but gnome-remote-desktop does not function correctly in Ubuntu 21.04
Vino, the VNC server previously used by Gnome, has been deprecated. Vino has been replaced by gnome-remote-desktop, but as currently integrated, gnome-remote-desktop does not function correctly in Ubuntu 21.04.
When configured using the standard Gnome control panel settings (Settings, Sharing, Screen Sharing):
This is the error that appears when trying to connect, in both xorg and wayland:
This is a good reminder of why one should use an LTS release for production servers
A good suggested practice is to run LTS releases on production servers, but run recent releases on workstation laptops. This allows for issues to be identified and workarounds devised before the next LTS release, in case the problem persists in the next LTS release.
Why would one want to access the Graphical User Interface (GUI) desktop of a Linux server?
For some server tasks, it is helpful to be able to access the GUI desktop of the server via a remote viewer. For example, you may need to install a GUI operating system as a guest, and access its GUI desktop from the console of your server’s GUI desktop.
Disabling Wayland
Wayland is an alternative to the xorg windows system. One day, it will be terrific. For now, it does not work with x11vnc or other important applications like TeamViewer.
sudo su
cd /etc/gdm3
nano custom.conf
# Uncomment the line below to force the login screen to use Xorg
WaylandEnable=false
reboot
A reminder about the firewall and opening port 5900/tcp
From a shell window, enter the following commands:
sudo su
ufw allow 5900/tcp
ufw allow 5901/tcp
exit
Disabling the existing (broken) screen sharing server
Settings, Sharing, Screen Sharing:
Installing the x11vnc package
From a shell window, enter the following commands:
sudo su
apt install x11vnc
exit
Creating a password for x11vnc
From a shell as the user that owns the Gnome desktop session, enter these commands. When prompted, supply a password:
whoami
x11vnc -storepasswd
A friendly warning about security
Different situations can accept different levels of risk. The VNC protocol as implemented, sends data as cleartext over a network connection. This may be acceptable over a local area network, particularly if you have VLAN segmentation and good wifi encryption enabled on your house Local Area Network (LAN).
Do not even consider sending this kind of unencrypted traffic over the public Internet. Use a VPN, or redirect the connection via SSH tunnelling.
Starting the server manually
From a shell as the user that owns the Gnome desktop session, enter these commands. When prompted, supply a password:
From a shell window, enter the following commands:
sudo su
apt install net-tools
ifconfig
exit
(Note: the command:
ip a
provides an equivalent result. But ifconfig is easier to read.)
Connecting to the server from a client
From another computer on the same local area network, connect to the IP address of the machine on which x11vnc is running. Attempt to connect using a VNC client such as RealVNC, tightvnc, or remmina:
Creating a script that contains the x11vnc command line options
From a shell as the user that owns the Gnome desktop session, enter these commands:
cd ~
whoami
nano x11vncstartup.sh
Enter this text. Press Control-X to save and exit:
Ma présentation à Linux-Meetup Montréal décrivant comment héberger Windows Server 2019 en tant qu’invité virtuel sous Linux KVM, et comment configurer Samba pour respecter Active Directory pour le stockage de fichiers réseau.
Web presence step by step is a series of posts that show you to how to build a web presence.
In this post, we learn how to declare multiple subdomain names under a single domain name for use as virtual host names, for multiple separate websites.
Understanding virtual hosts and their relation to domain and subdomain names
A shared LAMP web server can host multiple websites, or “virtual hosts,” named after domain and subdomain names.
You may wish to host a web-based application like MyBB or Nextcloud as its own website, rather than as a subdirectory of an existing website, without purchasing an additional domain name.
Multiple subdomains can be hosted on the same web server, or on different web servers.
The bare domain and the www subdomain
A virtual host can be identified by a “bare” domain name like “webpresencestepbystep.com,” or by a subdomain name, like “www.webpresencestepbystep.com” — by convention, the www subdomain prefix points to the same content as the “bare” domain name.
Additional subdomains like “community” and “media”
Additional subdomain names can be declared like “community.webpresencestepbystep.com” and “media.webpresencestepbystep.com” – these subdomains can point to separate websites on the same web server, or on different web servers.
Understanding domain and subdomain names and their relation to Domain Name System (DNS) zone files
As we can see in the DNS zone for the domain, the host names “@” (“bare domain”) and “community” are A declarations associated with the IP address of web server A.
The host name “www” is a CNAME declaration associated with the host name “@” so implicitly is associated with the IP address of web server A.
The host name “media” is an A declaration associated with the IP address of web server B.
2 websites on web server A, 1 website on web server B, all as subdomains of a single domain name
By using multiple subdomains of the same domain name, 3 separate websites can be declared, with 2 websites hosted on web server A, and 1 website hosted on web server B, without the need to purchase additional domain names.
Bare domain and subdomain www on web server A
webpresencestepbystep.com and www.webpresencestepbystep.com on web server A
A note about www and CNAME
the subdomain “www” host name is a canononical name (“CNAME”) of the @ host name, which identifies the “bare” domain. This means that www.webpresencestepbystep.com will resolve to the same IP address as webpresencestepbystep.com
