Integrating open source software in the enterprise Chapter 1: Creating a network file share with Linux and Samba authenticating against Active Directory

Integrating open source software in the enterprise is a series of posts that show you how to deploy open source software tools in an enterprise setting, interoperating with established commercial software such as Windows Server and Active Directory.

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 Ubuntu Linux 22.04 LTS

Understanding the test network

This procedure was tested on a network of 3 virtual machines, each running in bridge mode, on different hypervisor hosts.

sudburyWindows Server 2019 acting as Active Directory controller for the clarkcounty.gordonbuchan.com domain.
sandiegoUbuntu 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.
hamiltonWindows 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.

Setting the system hostname

hostnamectl set-hostname sandiego.clarkcounty.gordonbuchan.com

Configuring the /etc/hosts file

Associate the host name of your Linux server with its IP address:

cd /etc
nano hosts
192.168.33.110   sandiego
192.168.33.110   sandiego.clarkcounty.gordonbuchan.com

Setting DNS

Disable systemd-resolved service:

systemctl stop systemd-resolved
systemctl disable systemd-resolved

Unlink the symbolic link /etc/resolv.conf:

cd /etc
unlink resolv.conf

Creating a new /etc/resolv.conf file

Ensure that the first nameserver entry is the IP address of the Active Directory server.

nano resolv.conf
nameserver 192.168.33.80
nameserver 8.8.8.8
search clarkcounty.gordonbuchan.com
reboot

Installing software

apt install acl samba winbind libnss-winbind krb5-user

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.

Configuring Kerberos

cd /etc
cp krb5.conf krb5.conf.orig
nano krb5.conf
[libdefaults]
default_realm = CLARKCOUNTY.GORDONBUCHAN.COM
dns_lookup_realm = false
dns_lookup_kdc = true

Configuring Nsswitch

cd /etc
cp nsswitch.conf nsswitch.conf.orig
nano nsswitch.conf
passwd: files winbind
group: files winbind
hosts: files dns wins
chmod 550 nsswitch.conf

Configuring Samba (1/2)

cd /etc/samba
cp smb.conf smb.conf.orig
nano smb.conf
[global]
   realm = CLARKCOUNTY.GORDONBUCHAN.COM
   security = ADS
   workgroup = CLARKCOUNTY

   idmap config SAMDOM : range = 10000 - 999999
   idmap config SAMDOM : backend = rid
   idmap config * : range = 3000-7999
   idmap config * : backend = tdb

   map acl inherit = Yes
   vfs objects = acl_xattr

   dedicated keytab file = /etc/krb5.keytab
   kerberos method = secrets and keytab
   winbind refresh tickets = Yes

Obtaining a Kerberos ticket

kinit admingordon
klist

Joining the Active Directory domain

net ads info testjoin
net ads -v join -U admingordon
net ads info

Restarting services (1/2)

systemctl restart smbd nmbd winbind

Creating the share folder

cd /home
mkdir example_share
chmod -R 2770 example_share
chown -R "CLARKCOUNTY\admingordon":"CLARKCOUNTY\example_group" example_share

Configuring Samba (2/2)

cd /etc/samba
cp smb.conf smb.conf.orig
nano smb.conf
   [Share]
   acl_xattr:ignore system acl = Yes
   acl allow execute always = Yes
   acl group control = Yes
   inherit acls = Yes
   inherit owner = windows and unix
   inherit permissions = Yes
   path = /media/share
   read only = No

Restarting services (2/2)

systemctl restart smbd nmbd winbind

Mapping sid==5-1-5-32-546 to nogroup

This SID must be mapped to the UNIX group nogroup:

net groupmap add sid=S-1-5-32-546 unixgroup=nogroup type=builtin

Connecting to the network file share from a Windows computer joined to the domain

Applying Windows Access Control Lists (ACLs) from a Windows computer joined to the domain

References

http://blog.jrg.com.br/2021/02/01/ubuntu-focal-fossa-samba-domain-member-shares-1/
https://docs.vmware.com/en/VMware-Horizon-7/7.13/linux-desktops-setup/GUID-F8F0CFCF-C4D6-4784-85FF-E7C6DF575F49.html
https://ubuntu.com/server/docs/service-sssd-ad
https://wiki.samba.org/index.php/Setting_up_Samba_as_a_Domain_Member
https://www.jurisic.org/post/2021/11/24/SAMBA-Domain-Member-as-File-Server
https://www.moderndeployment.com/windows-server-2019-active-directory-installation-beginners-guide/
https://www.reddit.com/r/Ubuntu/comments/h01i2w/cheat_sheet_on_how_to_configure_a_smb_file_server/

Web presence step by step Chapter 18: Installing VirtualBox on a computer running Windows to host Linux as a virtual machine (VM) guest

Previous step Chapter 17: Using subdomains to host multiple websites under a single 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.

This image has an empty alt attribute; its file name is image-26.png

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.

Downloading VirtualBox

https://www.virtualbox.org/wiki/Downloads

Installing VirtualBox

Downloading Ubuntu desktop Linux

https://ubuntu.com/download/desktop

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”:

Network considerations at the VM guest level

Allowing a port exception in the firewall

Setting a static IP address

Installing and starting the SSH terminal server

Enabling remote desktop access with x11vnc

To enable remote desktop access, please refer to this post: Installing x11vnc to replace broken screen sharing on Ubuntu 21.04.

Previous step Chapter 17: Using subdomains to host multiple websites under a single domain name

Installing x11vnc to replace broken screen sharing on Ubuntu 21.04

After upgrading from Ubuntu 20.10 to Ubuntu 21.04, screen sharing (VNC server) is no longer functioning correctly.

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
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:

whoami
x11vnc -display :0 -forever -shared -rfbauth /home/desktop/.vnc/passwd

Testing the x11vnc screen sharing server

Determining the IP address of your computer

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:

#!/usr/bin/bash
x11vnc -display :0 -forever -shared -rfbauth /home/desktop/.vnc/passwd

Enter this command:

chmod 755 x11vncstartup.sh

Testing the script manually

From a shell as the user that owns the Gnome desktop session, enter these commands:

cd ~
./x11vncstartup.sh

Test as described earlier in the section “Testing the x11vnc screen sharing server.”

Adding the script to Startup Applications

Go to Show Applications. search for “startup applications,” click on its icon:

Click Add:

Name: x11vncstartup.sh

Click the “Browse…” button. Select the file x11vncstartup.sh, Click “Open”:

Comment: x11vncstartup.sh

Click on “Add”:

Click on “Close”:

Testing that x11vnc was started as a script in “Startup Applications”

Reboot the computer. Log into the computer’s desktop.

Test as described earlier in the section “Testing the x11vnc screen sharing server.”

Web presence step by step Chapter 17: Using subdomains to host multiple websites under a single domain name

Previous step Chapter 16: Using a script to automate the creation of a virtual host on an Apache web server
Next step: Chapter 18: Installing VirtualBox on a computer running Windows to host Linux as a virtual machine (VM) guest

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

Virtual host profiles

/etc/apache2/sites-available/webpresencestepbystep.com.conf:

# generated 2021/05/18 19:42:53 EDT by addvhost.php
<VirtualHost *:80>
<IfModule mpm_itk_module>
AssignUserID webpresencestepbystep_com webpresencestepbystep_com
</IfModule>
ServerName webpresencestepbystep.com
ServerAlias www.webpresencestepbystep.com
DocumentRoot /usr/web/webpresencestepbystep_com/webpresencestepbystep.com
ServerAdmin info@yourdomain.com
CustomLog /var/log/apache2/webpresencestepbystep.com-access_log combined
ErrorLog /var/log/apache2/webpresencestepbystep.com-error_log
RewriteEngine on
RewriteCond %{SERVER_NAME} =webpresencestepbystep.com [OR]
RewriteCond %{SERVER_NAME} =www.webpresencestepbystep.com
RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [END,NE,R=permanent]
</VirtualHost>

/etc/apache2/sites-available/webpresencestepbystep.com-le-ssl.conf:

<IfModule mod_ssl.c>
<VirtualHost *:443>
<IfModule mpm_itk_module>
AssignUserID webpresencestepbystep_com webpresencestepbystep_com </IfModule>
ServerName webpresencestepbystep.com
ServerAlias www.webpresencestepbystep.com
DocumentRoot /usr/web/webpresencestepbystep_com/webpresencestepbystep.com ServerAdmin info@yourdomain.com CustomLog /var/log/apache2/webpresencestepbystep.com-access_log combined ErrorLog /var/log/apache2/webpresencestepbystep.com-error_log Include /etc/letsencrypt/options-ssl-apache.conf SSLCertificateFile /etc/letsencrypt/live/linuxstepbystep.com/fullchain.pem SSLCertificateKeyFile /etc/letsencrypt/live/linuxstepbystep.com/privkey.pem
</VirtualHost>
</IfModule> 

Website

Subdomain community on web server A

community.webpresencestepbystep.com on the same IP address, on web server A

Virtual host profiles

/etc/apache2/sites-available/community.webpresencestepbystep.com.conf:

# generated 2021/05/29 12:45:14 EDT by addvhost.php
<VirtualHost *:80>
<IfModule mpm_itk_module>
AssignUserID community_webpresencestepbystep_ community_webpresencestepbystep_
</IfModule>
ServerName community.webpresencestepbystep.com
DocumentRoot /usr/web/community_webpresencestepbystep_/community.webpresencestepbystep.com
ServerAdmin info@yourdomain.com
CustomLog /var/log/apache2/community.webpresencestepbystep.com-access_log combined
ErrorLog /var/log/apache2/community.webpresencestepbystep.com-error_log
RewriteEngine on
RewriteCond %{SERVER_NAME} =community.webpresencestepbystep.com
RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [END,NE,R=permanent]
</VirtualHost>

/etc/apache2/sites-available/community.webpresencestepbystep.com-le-ssl.conf

<IfModule mod_ssl.c>
<VirtualHost *:443>
<IfModule mpm_itk_module>
AssignUserID community_webpresencestepbystep_ community_webpresencestepbystep_
</IfModule>
ServerName community.webpresencestepbystep.com
DocumentRoot /usr/web/community_webpresencestepbystep_/community.webpresencestepbystep.com
ServerAdmin info@yourdomain.com
CustomLog /var/log/apache2/community.webpresencestepbystep.com-access_log combined
ErrorLog /var/log/apache2/community.webpresencestepbystep.com-error_log
SSLCertificateFile /etc/letsencrypt/live/linuxstepbystep.com/fullchain.pem
SSLCertificateKeyFile /etc/letsencrypt/live/linuxstepbystep.com/privkey.pem
Include /etc/letsencrypt/options-ssl-apache.conf
</VirtualHost>
</IfModule>

Website

Subdomain media on web server B

media.webpresencestepbystep.com on a different IP address, on web server B

Virtual host profiles

/etc/apache2/sites-available/media.webpresencestepbystep.com.conf:

# generated 2021/05/29 17:12:33 UTC by addvhost.php
<VirtualHost *:80>
<IfModule mpm_itk_module>
AssignUserID media_webpresencestepbystep_com media_webpresencestepbystep_com
</IfModule>
ServerName media.webpresencestepbystep.com
DocumentRoot /usr/web/media_webpresencestepbystep_com/media.webpresencestepbystep.com
ServerAdmin info@yourdomain.com
CustomLog /var/log/apache2/media.webpresencestepbystep.com-access_log combined
ErrorLog /var/log/apache2/media.webpresencestepbystep.com-error_log
RewriteEngine on
RewriteCond %{SERVER_NAME} =media.webpresencestepbystep.com
RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [END,NE,R=permanent]
</VirtualHost>

/etc/apache2/sites-available/media.webpresencestepbystep.com-le-ssl.conf

<IfModule mod_ssl.c>
<VirtualHost *:443>
<IfModule mpm_itk_module>
AssignUserID media_webpresencestepbystep_com media_webpresencestepbystep_com
</IfModule>
ServerName media.webpresencestepbystep.com
DocumentRoot /usr/web/media_webpresencestepbystep_com/media.webpresencestepbystep.com
ServerAdmin info@yourdomain.com
CustomLog /var/log/apache2/media.webpresencestepbystep.com-access_log combined
ErrorLog /var/log/apache2/media.webpresencestepbystep.com-error_log
SSLCertificateFile /etc/letsencrypt/live/media.webpresencestepbystep.com/fullchain.pem
SSLCertificateKeyFile /etc/letsencrypt/live/media.webpresencestepbystep.com/privkey.pem
Include /etc/letsencrypt/options-ssl-apache.conf
</VirtualHost>
</IfModule>

Website

Previous step Chapter 16: Using a script to automate the creation of a virtual host on an Apache web server
Next step: Chapter 18: Installing VirtualBox on a computer running Windows to host Linux as a virtual machine (VM) guest

Web presence step by step Chapter 16: Using a script to automate the creation of a virtual host on an Apache web server

Previous step: Chapter 15: Using dwservice.net to provide remote technical support as an alternative to TeamViewer
Next step: Chapter 17: Using subdomains to host multiple websites under a single domain name

Web presence step by step is a series of posts that show you to how to build a web presence.

In this chapter we install and use a script to automate the creation of a virtual host on an Apache web server.

A PHP script that automates the creation of a virtual host under Apache

This script collects and validates inputs, then executes the commands to create a virtual host under Apache.

A note about the source code view below

For formatting reasons, the text is limited to a fixed width. To fully view the text, you can scroll to the right to see the ends of lines, or use the print view for this blog post.

To view the source code in an another text editor, download and uncompress the zip file described below, or select and copy the text from the source code example below, and paste the text into a file on your computer called “addvhost.php”

Consider copying the file to your Apache web server’s /usr/bin directory with a chmod of 755 so that it can be executed from the system path. Steps to do so are included in the procedure below.

Saving the PHP script to a file called addvhost.php

Download this zip file:

https://blog.gordonbuchan.com/files/addvhost.zip

Uncompress the zip file to extract the file “addvhost.php” then copy the file to your Apache web server.

Source code of the script

Scroll right to see the ends of lines.

#!/usr/bin/php
<?PHP
// addvhost.php
// v0102
// updated to variable-ize vhostip as a base setting
// creates a virtual host under Apache
// Gordon Buchan 20210512 https://gordonbuchan.com
// MIT License https://mit-license.org
// tested on Ubuntu 20.04, may work on Debian
// directory structure allows for chroot jails for SFTP:
// in a jail you do not own your home directory, only your webdir
// tip: apt install finger whois
// ////////////////////////////////////////////////////////////////
// start summary
// initialize base settings in variables ie bvhwb
// ask for vhostsubdomain, vhostusername, vhostpassword
// infer vhosthomedir, vhostwebdir by convention
// create user, home directory, password
// create directory
// create index.php document
// chown vhosthomedir as root:root
// chown vhostwebdir as vhostusername:vhostusername
// chmod vhostwebdir
// create virtual host file
// enable virtual host
// echo suggestion that client restart apache, run certbot --apache, restart apache
// end summary

// ////////////////////////////////////////////////////////////////
// start base settings

$bvhostconfdir = "/etc/apache2/sites-available";
$bvhwb = "/usr/web";
$restartcommandstr = "systemctl apache2 restart";
$vhostenablecommandstr = "a2enmod";
$echoplaintextpasswords = TRUE;
$logplaintextpassword = TRUE;
$vhostserveradmin = "info@yourdomain.com";
// tip: could be "xxx.xxx.xxx.xxx"
$vhostip = "*";

// ////////////////////////////////////////////////////////////////
// end base settings

// ////////////////////////////////////////////////////////////////
// start function sink
 
// start polyfill
// str_contains() polyfill for pre PHP8: code for this function taken from php.net
if (!function_exists('str_contains')) {
	function str_contains(string $haystack, string $needle): bool 
	{
	return '' === $needle || false !== strpos($haystack, $needle);
	} // end function str_contains()
}
// ////////////////////////////////////////////////////////////////
// end polyfill

// validate functions
// We will be using the readline() function to ask questions on the command line.
// These functions allow us to do rich validation within a while statement to trap
// the readline in a loop until our conditions are satisfied.
// We will also echo text to the console with reasons for rejection to assist the client.
// For example: bad string format, vhost appears to exist already, etc.

// ////////////////////////////////////////////////////////////////
function vhostsubdomainverify($vhostsubdomainstr) {
global $bvhwb;
global $bvhostconfdir;

//assume true until proven false
$returnval = TRUE;

// is the string clean?
// note that "-" hyphen character is permitted, not part of symbol sieve
if ( preg_match('/[\'^£$%&*()}{@#~?><>,|=_+¬]/', $vhostsubdomainstr) ) {
	$returnval = FALSE;
	echo "string has special character that is not permitted\n";
}

// string does not contain a period symbol
if (!str_contains($vhostsubdomainstr,".") ) {
	$returnval = FALSE;
	echo "string does not contain a \".\" period symbol.\n";
}

// string contains two period symbols in a row
if (str_contains($vhostsubdomainstr,"..") ) {
	$returnval = FALSE;
	echo "string contain two \"..\" period symbols in a row.\n";
}

// string contains leading period symbol
$strlen = strlen($vhostsubdomainstr);
$begsample = substr($vhostsubdomainstr,0,1);
if ($begsample == ".") {
	$returnval = FALSE;
	echo "string begins with a \".\" period symbol.\n";
}

// string contains trailing period symbol
$endlen = strlen($vhostsubdomainstr);
$endsample = substr($vhostsubdomainstr,($endlen - 1),1);
if ($endsample == ".") {
	$returnval = FALSE;
	echo "string ends with a \".\" period symbol.\n";
}

// does the vhostsubdomain already exist?
$vhostsubdomainstrund = str_replace(".","_",$vhostsubdomainstr);
clearstatcache();
if (is_dir("$bvhwb/$vhostsubdomainstrund") ) {
	$returnval = FALSE;
	echo "webdir for proposed vhost already exists.\n";
} else {
} // end if (is_dir()

$grepforvhost1str = "grep -i 'ServerName $vhostsubdomainstr' $bvhostconfdir/*";
$grepforvhost2str = "grep -i 'ServerAlias $vhostsubdomainstr' $bvhostconfdir/*";
$grepforvhost1res = shell_exec($grepforvhost1str);
$grepforvhost2res = shell_exec($grepforvhost2str);

// if the string has contents something was there for the grep to find
if ($grepforvhost1res || $grepforvhost2res) {
	echo "subdomain appears to be part of an existing virtual host\n";
	$returnval = FALSE;
}

return $returnval;
} // end function vhostsubdomainverify()

// ////////////////////////////////////////////////////////////////
function prependverify($prependverify) {

// let us make our tests and comparisons case-insensitive
$lowerpv = strtolower($prependverify);

if ( ( $lowerpv == "n") || ($lowerpv == "no") || ($lowerpv == "y") || ($lowerpv == "yes") ) {
	$returnval = TRUE;
} else {
	echo "please indicate n or no, y or yes\n";
	$returnval = FALSE;
}

return $returnval;
} // end function prependverify()

// ////////////////////////////////////////////////////////////////
function usernameverify($vhostusername) {

// force to lower-case
$vhostusername = strtolower($vhostusername);

// assume TRUE until proven false
$returnval = TRUE;

// is the string clean?
// note that "-" hyphen character is permitted, as is the "_" underscore character, not part of symbol sieve
if ( preg_match('/[\'^£$%&*()}{@#~?><>,|=+¬]/', $vhostusername) ) {
	$returnval = FALSE;
	echo "string has special character that is not permitted\n";
}

$vhunstrlen = strlen($vhostusername);

if ($vhunstrlen < 2) {
	echo "username should be minimum 2 characters\n";
	$returnval = FALSE;
}
if ($vhunstrlen > 32) {
	echo "username should be maximum 32 characters\n";
	$returnval = FALSE;
}

// what does finger return?
$fingerstr = shell_exec("finger $vhostusername 2>&1");

if (!str_contains("$fingerstr","no such user") ) {
	echo "finger found this username to already be in use\n";
	$returnval = FALSE;
}

return $returnval;
} // end function usernameverify()

// ////////////////////////////////////////////////////////////////
function passwordplainverify($passwordplain) {

// assume TRUE until proven false
$returnval = TRUE;

// we should do some tests here
// but mostly just for length, not all that fancy stuff.
// but: we will want to offer to auto-generate a plaintext password

$ppstrlen = strlen($passwordplain);

if ($ppstrlen < 8) {
	echo "password should be at least 8 characters\n";
	$returnval = FALSE;
}

return $returnval;
} // end function passwordplainverify()

// ////////////////////////////////////////////////////////////////
function genpassverify($genpassverify) {

// let us make our tests and comparisons case-insensitive
$lowergpv = strtolower($genpassverify);

if ( ( $lowergpv == "n") || ($lowergpv == "no") || ($lowergpv == "y") || ($lowergpv == "yes") ) {
	$returnval = TRUE;
} else {
	echo "please indicate n or no, y or yes\n";
	$returnval = FALSE;
}

return $returnval;
} // end function genpassverify()

// ////////////////////////////////////////////////////////////////
function genuserverify($genuserverify) {

// let us make our tests and comparisons case-insensitive
$lowerguv = strtolower($genuserverify);

if ( ( $lowerguv == "n") || ($lowerguv == "no") || ($lowerguv == "y") || ($lowerguv == "yes") ) {
	$returnval = TRUE;
} else {
	echo "please indicate n or no, y or yes\n";
	$returnval = FALSE;
}

return $returnval;
} // end function genuserverify()

// end function sink

// ////////////////////////////////////////////////////////////////
// start get information at command line: vhostsubdomain, vhostusername, vhostpassword
// also, generate and derive values
echo "\naddvhost.php\n";
echo "Add a virtual host to Apache\n\n";

// ask and validate inputs
// the readline is trapped in a loop until vhostsubdomainverify() is satisfied
// function will also echo text to the console with reasons for rejection to assist the client
// bad string format or vhost appears to exist already, etc.

// ////////////////////////////////////////////////////////////////
// vhostsubdomain

$vhostsubdomain = "";
while (!$vhostsubdomain || !vhostsubdomainverify($vhostsubdomain) ) {
    $vhostsubdomain = readline("Enter domain xxxxxxxx.xxx or subdomain xxxxxxxx.xxxxxxxx.xxx: ");
}

// putting this here because it is right after we have the $vhostsubdomain string, and just before we need it for $genuseranswer
// will also need this later for derived values like the $vhostwebdir

$vhostsubdomainund = str_replace(".","_",$vhostsubdomain);

// should we prepend with www. as well?

$prependanswer = "";
while (!$prependanswer || !prependverify($prependanswer) ) {
    $prependanswer = readline("Do you wish to prepend the subdomain www.$vhostsubdomain as well (n/y)? ");
}

$prependanswer = strtolower($prependanswer);

// ////////////////////////////////////////////////////////////////
// vhostusername

// default username
// should we offer to automatically generate a username based on the subdomain host name?

$genuseranswer = "";
while (!$genuseranswer || !genuserverify($genuseranswer) ) {
    $genuseranswer = readline("Generate a username? ");
}

$genuseranswer = strtolower($genuseranswer);

if ( ($genuseranswer=="yes") || ($genuseranswer=="y") ) {
	// generate a username
	// we are counting on the novel construction of this name with _ modeled on subdomain

	$vhostusername = $vhostsubdomainund;
	$vhostusernamestrlen = strlen($vhostusername);
	// the unique stuff is closer to the front
	// so we will truncate to first 32 characters
	if ($vhostusernamestrlen > 32) {
		$vhostusername = substr($vhostusername,0,32);
	}

	// what does finger return?
	$fingerstr2 = shell_exec("finger $vhostusername 2>&1");
	if (!str_contains("$fingerstr2","no such user") ) {
		echo "finger found this username to already be in use\n";
		exit();
	}

} else {
	// the client said no to automatic generation of username so we will ask for one
	$vhostusername = "";
	while (!$vhostusername || !usernameverify($vhostusername) ) {
	    $vhostusername = readline("Enter username: ");
	}
} // end if ($genuseranswer=="yes")

// ////////////////////////////////////////////////////////////////
// vhostpasswordplain

// should we offer to automatically generate a plaintext password?

$genpassanswer = "";
while (!$genpassanswer || !genpassverify($genpassanswer) ) {
    $genpassanswer = readline("Generate a plaintext password? ");
}

$genpassanswer = strtolower($genpassanswer);

if ( ($genpassanswer=="yes") || ($genpassanswer=="y") ) {
	// generate a random plaintext password
	$vhostpasswordplain = "";
	$passwordlength = "8";
	$posscharsplain = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
	$posscharssymbols = '!@#%*?';
	$posscharspstrlen = strlen($posscharsplain);
	$posscharssstrlen = strlen($posscharssymbols);
	// first the plain characters
	for ($i=0;$i<($passwordlength-1);$i++) {
		$randomint = random_int(0,$posscharspstrlen-1);
		$randomchar = substr($posscharsplain,$randomint,1);
		$vhostpasswordplain .= $randomchar;
	} //end for $i
	// now the symbol character
		$randomint = random_int(0,$posscharssstrlen-1);
		$randomchar = substr($posscharssymbols,$randomint,1);
		$vhostpasswordplain .= $randomchar;
	// now shuffle the string so the symbol position moves and as bonus the string is different
	$vhostpasswordplain = str_shuffle($vhostpasswordplain);
} else {
	// the client said no to automatic generation of plaintext, so we will ask for one
	$vhostpasswordplain = "";
	while (!$vhostpasswordplain || !passwordplainverify($vhostpasswordplain) ) {
		$vhostpasswordplain = readline("Enter plaintext password: ");
	}
} // end if ($genpassanswer=="yes")

// ////////////////////////////////////////////////////////////////
// vhostpasswordhashed (transformation)

// yes, i tried password_hash() -- it did not work for SHA512, this does.
// tip: apt install whois to get mkpasswd command
$vhostpasswordhashed = shell_exec("mkpasswd -m sha-512 $vhostpasswordplain");
// remove linefeed from the string
$vhostpasswordhashed = str_replace("\n","",$vhostpasswordhashed);

// ////////////////////////////////////////////////////////////////
// end get information at command line: vhostsubdomain, vhostusername, vhostpassword

// ////////////////////////////////////////////////////////////////
// start print collected values

$vhosthomedir = "$bvhwb/$vhostusername";
$vhostwebdir = "$bvhwb/$vhostusername/$vhostsubdomain";

echo "\nvalues collected, generated, and derived\n\n";

echo "vhostsubdomain: $vhostsubdomain\n";
echo "prependanswer: $prependanswer\n";
echo "vhostusername: $vhostusername\n";
echo "genpassanswer: $genpassanswer\n";
if ($echoplaintextpasswords) {
	echo "vhostpasswordplain: $vhostpasswordplain\n";
}
echo "vhostpasswordhashed: $vhostpasswordhashed\n";
echo "vhosthomedir: $vhosthomedir\n";
echo "vhostwebdir: $vhostwebdir\n";

// ////////////////////////////////////////////////////////////////
// end print collected values

// ////////////////////////////////////////////////////////////////
// start engine section

// ////////////////////////////////////////////////////////////////
// create the $vhostusername with $vhosthomedir and $vhostpasswordhashed

// build the string, look at the string, then maybe do a shell_exec of the string
$shelluseraddstr = "useradd -m -d '$vhosthomedir' '$vhostusername' -s '/usr/bin/bash' -p '$vhostpasswordhashed'";

// disable for production
// echo "shelluseraddstr: $shelluseraddstr\n";

// so it will always be declared
$shelluseraddret = "";
// disable for testing other conditions without committing to this
$shelluseraddret = shell_exec($shelluseraddstr);

//echo "shelluseraddret: $shelluseraddret\n";
// non-null (non-0) exit value from shell indicates an error
if ($shelluseraddret) {
	echo "ERROR: there was a problem executing the shell command to create the vhostusername $vhostusername. Stopping.\n";
	exit();
} else {
	//echo "SUCCESS: the vhostusername $vhostusername was created\n";
}

echo "\n";

// ////////////////////////////////////////////////////////////////
// mkdir $vhostwebdir

$mkdirvhostwebdirret = mkdir($vhostwebdir,0775,TRUE);

if (!$mkdirvhostwebdirret) {
	echo "ERROR: there was a problem creating the vhostwebdir $vhostwebdir. Stopping\n";
	exit();
} else {
	//echo "SUCCESS: the vhostwebdir $vhostwebdir was created.\n";
}

// ////////////////////////////////////////////////////////////////
// fwrite $vhostwebdir/index.php

$indexfilecontents = "<?PHP\n\necho \"<p>$vhostsubdomain</p>\\n\";\n";

$fh1 = fopen("$vhostwebdir/index.php","w");
$filesuccess1 = fwrite($fh1,$indexfilecontents);
fclose($fh1);
 
if ($filesuccess1) {

	//chown root $vhosthomedir

	$vhosthomedirownretu1 = chown("$vhosthomedir","root");
	if ($vhosthomedirownretu1) {
		//echo "SUCCESS chown root $vhosthomedir\n";
	} else {
		echo "ERROR chown root $vhosthomedirdir not successful\n";
		exit();
	}

	//chgrp root $vhosthomedir

	$vhosthomedirownretg1 = chgrp("$vhosthomedir","root");
	if ($vhosthomedirownretg1) {
		//echo "SUCCESS chgrp root $vhosthomedir\n";
	} else {
		echo "ERROR chgrp root $vhosthomedirdir not successful\n";
		exit();
	}

	//echo "SUCCESS indexfile written to file: $vhostwebdir/index.php\n";

	// chmod the $vhostwebdir
	chmod("$vhostwebdir", 0755);
	$vhostwebdirperms = substr(sprintf('%o', fileperms("$vhostwebdir")), -4);
	//echo "vhostwebdirperms: $vhostwebdirperms\n";
	if ($vhostwebdirperms == "0755") {
		//echo "SUCCESS chmod 755 $vhostwebdir\n";
	} else {
		echo "ERROR chmod 755 $vhostwebdir not successful. Stopping.\n";
	exit();
	}

	// chown $vhostusername $vhostwebdir
	$vhostwebdirownretu1 = chown("$vhostwebdir",$vhostusername);
	if ($vhostwebdirownretu1) {
		//echo "SUCCESS chown $vhostusername $vhostwebdir\n";
	} else {
		echo "ERROR chown $vhostusername $vhostwebdir not successful\n";
		exit();
	}

	// chgrp $vhostusername $vhostwebdir
	$vhostwebdirownretg1 = chgrp("$vhostwebdir",$vhostusername);
	if ($vhostwebdirownretu1) {
		//echo "SUCCESS chgrp $vhostusername $vhostwebdir\n";
	} else {
		echo "ERROR chgrp $vhostusername $vhostwebdir not successful\n";
		exit();
	}

	// chmod the $vhostwebdir/index.php
	chmod("$vhostwebdir/index.php", 0755);
	$vhostindexperms = substr(sprintf('%o', fileperms("$vhostwebdir/index.php")), -4);
	//echo "vhostindexperms: $vhostindexperms\n";
	if ($vhostindexperms == "0755") {
		//echo "SUCCESS chmod 755 $vhostwebdir/index.php\n";
	} else {
		echo "ERROR chmod 755 $vhostwebdir/index.php not successful. Stopping.\n";
	exit();
	}

	// chown $vhostusername $vhostwebdir/index.php
	$vhostindexownretu1 = chown("$vhostwebdir/index.php",$vhostusername);
	if ($vhostindexownretu1) {
		//echo "SUCCESS chown $vhostusername $vhostwebdir/index.php\n";
	} else {
		echo "ERROR chown $vhostusername $vhostwebdir/index.php not successful\n";
		exit();
	}

	// chgrp $vhostusername $vhostwebdir/index.php
	$vhostindexownretg1 = chgrp("$vhostwebdir/index.php",$vhostusername);
	if ($vhostindexownretu1) {
		//echo "SUCCESS chgrp $vhostusername $vhostwebdir/index.php\n";
	} else {
		echo "ERROR chgrp $vhostusername $vhostwebdir/index.php not successful\n";
		exit();
	}
} else {
	echo "ERROR indexfile not written to file: $vhostwebdir/index.php\n";
	exit();
}

// ////////////////////////////////////////////////////////////////
// fwrite $bvhostconfdir/$vhostsubdomain.conf

$timestring = date("Y/m/d H:i:s T");

$vhostconffilecontents  = "# generated $timestring by addvhost.php\n";
$vhostconffilecontents .= "<VirtualHost $vhostip:80>\n";
$vhostconffilecontents .= "<IfModule mpm_itk_module>\n";
$vhostconffilecontents .= "\tAssignUserID $vhostusername $vhostusername\n";
$vhostconffilecontents .= "</IfModule>\n";
$vhostconffilecontents .= "ServerName $vhostsubdomain\n";
if ( ($prependanswer == "y") || ($prependanswer == "yes") ) {
	$vhostconffilecontents .= "ServerAlias www.$vhostsubdomain\n";
}
$vhostconffilecontents .= "DocumentRoot $vhostwebdir\n";
$vhostconffilecontents .= "ServerAdmin $vhostserveradmin\n";
$vhostconffilecontents .= "CustomLog /var/log/apache2/$vhostsubdomain-access_log combined\n";
$vhostconffilecontents .= "ErrorLog /var/log/apache2/$vhostsubdomain-error_log\n";
$vhostconffilecontents .= "</VirtualHost>\n";

// disable in production
// echo "vhostconffilecontents = \n$vhostconffilecontents\n";

// write the text file
$fh2 = fopen("$bvhostconfdir/$vhostsubdomain.conf","w");
$filesuccess2 = fwrite($fh2,$vhostconffilecontents);
fclose($fh2);
 
if ($filesuccess2) {
	//echo "SUCCESS virtual host config written to file: $bvhostconfdir/$vhostsubdomain.conf\n";
} else {
 	echo "ERROR virtual host config not written to file: $bvhostconfdir/$vhostsubdomain.conf\n";
 	exit();
}

// ////////////////////////////////////////////////////////////////
// shell_exec a2ensite $bvhostconfdir/$vhostsubdomain.conf

// so it will always be declared
$shella2enret = "";
// disable for testing other conditions without committing to this
$shella2enret = shell_exec("a2ensite $vhostsubdomain.conf");

//echo "shella2enret: $shella2enret\n";
// non-null (non-0) exit value from shell indicates an error
if ( str_contains($shella2enret,"ERROR") ) {
	//echo "ERROR: there was a problem executing the shell command to enable the vhostsubdomain $vhostsubdomain. Stopping.\n";
	exit();
} else {
	echo "SUCCESS: enabled vhostsubdomain $vhostsubdomain\n";
}

// ////////////////////////////////////////////////////////////////
// echo to console suggestion that systemctl restart apache2 be executed

echo "\n";
echo "Next steps:\n";
echo "This script did not restart apache2. That is up to you.\n";
echo "systemctl restart apache2\n";
echo "validate site on port 80\n";
echo "run certbot --apache to expand ssl cert\n";
echo "systemctl restart apache2\n";
echo "validate site on port 443\n";
echo "\n";

// ////////////////////////////////////////////////////////////////
// end engine section

Declaring the host name in DNS

Declare the host name in the DNS zone file for the domain:

Testing that the host name loads a “park page”

Use a web browser to visit the host name:

Executing commands as root

This chapter assumes that you are logged in as the root user. If you are not already root, escalate using this command:

sudo su

Installing the finger, whois, and unzip utilities

This script depends on the finger, whois, and unzip utilities.

Enter this command:

apt install finger whois unzip

Downloading and uncompressing the addvhost.zip file

Enter this command:

wget https://blog.gordonbuchan.com/files/addvhost.zip

Enter this command:

unzip addvhost.zip

Enter these commands:

mv addvhost.php /usr/bin
chmod 755 /usr/bin/addvhost.php

Enter this command:

addvhost.php

Completing the addvhost.php questionnaire, entering a username and a plaintext password

In this example, we decline the option to generate a username, and enter a value for the username. We also decline the option to generate a plaintext password, and enter a value for the plaintext password.

root@server01:~# addvhost.php

addvhost.php
Add a virtual host to Apache

Enter domain xxxxxxxx.xxx or subdomain xxxxxxxx.xxxxxxxx.xxx: webpresencestepbystep.ca
Do you wish to prepend the subdomain www.webpresencestepbystep.ca as well (n/y)? y
Generate a username? n
Enter username: webuserca
Generate a plaintext password? n
Enter plaintext password: password

values collected, generated, and derived

vhostsubdomain: webpresencestepbystep.ca
prependanswer: y
vhostusername: webuserca
genpassanswer: n
vhostpasswordplain: password
vhostpasswordhashed: $6$IdLp5YrW.Z3Tvnm$hlRvIBour47UcZrVm0QA2YgLp2z3C3e5W7PwiS3o.KbZz.mtFeCvWdew/eemdec3Wz9t.WEIuIm3Q2EKTuXYd1
vhosthomedir: /usr/web/webuserca
vhostwebdir: /usr/web/webuserca/webpresencestepbystep.ca

SUCCESS: enabled vhostsubdomain webpresencestepbystep.ca

Next steps:
This script did not restart apache2. That is up to you.
systemctl restart apache2
validate site on port 80
run certbot --apache to expand ssl cert
systemctl restart apache2
validate site on port 443

Enter this command:

systemctl restart apache2

Enter this command:

certbot --apache

Enter this command:

systemctl restart apache2

Visiting the virtual host

Use a web browser to visit the host name:

Completing the addvhost.php questionnaire, accepting a generated username and plaintext password

In this example, we accept the option to generate a username. We also accept the option to generate a plaintext password.

Take careful note of the plaintext password value, as shown in the “vhostpasswordplain” field.

root@server01:~# addvhost.php

addvhost.php
Add a virtual host to Apache

Enter domain xxxxxxxx.xxx or subdomain xxxxxxxx.xxxxxxxx.xxx: webpresencestepbystep.com
Do you wish to prepend the subdomain www.webpresencestepbystep.com as well (n/y)? y
Generate a username? y
Generate a plaintext password? y

values collected, generated, and derived

vhostsubdomain: webpresencestepbystep.com
prependanswer: y
vhostusername: webpresencestepbystep_com
genpassanswer: y
vhostpasswordplain: NQeQ2%VT
vhostpasswordhashed: $6$Woe9pPUwnXqUP$9RW60p6SSNfqLJSi4BeAyhe89mBpyTELk2/at7eJcKqou5Q9Y6Nti4P7EoyTV0CBfin6SxlvNHvkZjrpEGxxX0
vhosthomedir: /usr/web/webpresencestepbystep_com
vhostwebdir: /usr/web/webpresencestepbystep_com/webpresencestepbystep.com

SUCCESS: enabled vhostsubdomain webpresencestepbystep.com

Next steps:
This script did not restart apache2. That is up to you.
systemctl restart apache2
validate site on port 80
run certbot --apache to expand ssl cert
systemctl restart apache2
validate site on port 443

Enter this command:

systemctl restart apache2

Enter this command:

certbot --apache

Enter this command:

systemctl restart apache2

Visiting the virtual host

Use a web browser to visit the host name:

Previous step: Chapter 15: Using dwservice.net to provide remote technical support as an alternative to TeamViewer
Next step: Chapter 17: Using subdomains to host multiple websites under a single domain name

Web presence step by step Chapter 15: Using dwservice.net to provide remote technical support as an alternative to TeamViewer

Previous step: Chapter 14: Installing and configuring Live Helper Chat to add text chat support to a website
Next step: Chapter 16: Using a script to automate the creation of a virtual host on an Apache web server

Web presence step by step is a series of posts that show you to how to build a web presence.

In this chapter we install and configure dwservice.net to provide remote technical support as an alternative to TeamViewer.

dwservice.net allows a client to share their computer’s desktop so you can provide technical support

When you build and maintain technical systems, you need to support the clients of those systems, including customers, colleagues, and contractors. dwservice.net allows you to invite a client to share their computer’s desktop so you can provide technical support.

Creating an account on the dwservice.net service

Visit the dwservice.net site:

https://dwservice.net

Create a username and password for the dwservice.net site. You will need it later in this procedure.

dwservice.net provides client software for the Windows, MacOS, and Linux operating systems

This chapter contains sections describing how to install the dwservice.net client for Windows, MacOS, and Linux.

Windows

Visiting the website to download the installer on a Windows workstation

Visit the dwservice.net site:

https://dwservice.net

Click on “Download”:

Click on “Download”:

Right-click on the file name, click “Show in folder”:

Using the dwservice.net client on a Windows workstation in run-once mode

Double-click on the file to run the dwagent.exe setup program:

Select “Run,” click on “Next”:

View on the Windows workstation:

Accessing the Windows workstation from the dwservice.net site

Visit the dwservice.net site:

https://dwservice.net

Enter the username and password displayed on the Windows workstation running the dwservice.net client, click on “Sign in”:

Resources available on the Windows workstation

This page shows the resources available on the Windows workstation:

Screen (remote desktop)

Remote control of the desktop of the Windows workstation:

Files and Folders

Access to the filesystem on the Windows workstation:

Shell

Access to the operating system shell prompt on the Windows workstation:

Installing the dwservice.net client on a Windows workstation to enable unattended access

Right-click on the “dwagent.exe” file. Select “Run as administrator”:

Select “Install,” click on “Next”:

Select “Yes,” click on “Next”:

Select “Creating a new agent, click on “Next”:

Enter the username and password of a valid dwservice.net account in the “DWS user” and DWS password” fields. Enter a name to describe the workstation in the “Agent name” field. Click on “Next”:

Click on “Close”:

Visit the dwservice.net site:

https://dwservice.net

Enter the username and password of a valid dwservice.net account in the “DWS user” and DWS password” fields. Click on “Sign in”:

Click on “Agents”:

Click on the icon for the Windows workstation:

Resources available on the Windows workstation

This page shows the resources available on the Windows workstation:

Screen (remote desktop)

Remote control of the desktop of the Windows workstation:

Files and Folders

Access to the filesystem on the Windows workstation:

Shell

Access to the operating system shell prompt on the Windows workstation:

MacOS

Visiting the website to download the installer on a MacOS workstation

Visit the dwservice.net site:

https://dwservice.net

Click on “Download”:

Click on “Download”:

Click on “Allow”:

Locate the downloaded file, click on it:

This error message appears. Click on “OK”:

On the MacOS workstation, launch “System Preferences.” Click on “Security & Privacy”:

Click on “Open Anyway”:

Click on “Open”:

The dwservice.net package opens:

Click on “DWAgent”:

Click on “Run”:

View on the MacOS workstation:

Accessing the MacOS workstation from the dwservice.net site

Visit the dwservice.net site:

https://dwservice.net

Enter the username and password displayed on the MacOS workstation running the dwservice.net client, click on “Sign in”:

The following message appears on the MacOS workstation. Click on “Open System Preferences”:

Click on “Quit Now”:

On the MacOS workstation, restart the dwservice.net client.

Accessing the MacOS workstation from the dwservice.net site (again)

Visit the dwservice.net site:

https://dwservice.net

Enter the username and password displayed on the MacOS workstation running the dwservice.net client, click on “Sign in”:

Resources available on the MacOS workstation

This page shows the resources available on the MacOS workstation:

This image has an empty alt attribute; its file name is Screenshot-from-2021-05-01-06-49-07-1024x725.png

Screen (remote desktop)

Remote control of the desktop of the MacOS workstation:

Files and Folders

Access to the filesystem on the MacOS workstation:

Shell

Access to the operating system shell prompt on the MacOS workstation:

Installing the dwservice.net client on a MacOS workstation to enable unattended access

Click on “Open”:

Select “Install,” click on “Next”:

enter the “User Name” and “Password” for the MacOS workstation, click on “OK”:

Click on “Next”:

Select “Yes,” click on “Next”:

Select “Creating a new agent,” click on “Next”:

Enter the username and password of a valid dwservice.net account in the “DWS user” and DWS password” fields. Enter a name to describe the workstation in the “Agent name” field. Click on “Next”:

Click on “Close”:

View of the DWAgent Monitor on MacOS:

Click on “OK”:

Visit the dwservice.net site:

https://dwservice.net

Enter the username and password of a valid dwservice.net account in the “DWS user” and DWS password” fields. Click on “Sign in”:

Click on “Agents”:

Click on the icon for the MacOS workstation:

Resources available on the MacOS workstation

This page shows the resources available on the MacOS workstation. Click on “Screen”:

Allowing the dwaggui program to record the computer’s screen (needed for Screen/remote desktop access)

Click on “Open System Preferences”:

Allow the dwgguilnc program to record the screen:

Screen (remote desktop)

Remote control of the desktop of the MacOS workstation:

Files and Folders

Access to the filesystem on the MacOS workstation:

Shell

Access to the operating system shell prompt on the MacOS workstation:

Linux

Ensuring that Wayland is disabled

dwservice.net is not compatible with the Wayland display server.

from a root operating system prompt (use “sudo su” if you are not yet logged in as root), enter these commands:

cd /etc/gdm3
nano custom.conf

(Note: the directory location varies by distribution. For the Fedora distribution, specify the directory “etc/gdm”).

Remove the # comment before “WaylandEnable=false”:

Save and exit the file:

If you had to remove the “#” sign before “WaylandEnable=false” then reboot the Linux workstation so the change can take effect.

Visiting the website to download the installer on a Linux workstation

Visit the dwservice.net site:

https://dwservice.net

Click on “Download”:

Using the dwservice.net client on a Linux workstation in run-once mode

Open a terminal window on the Linux desktop. Change to the folder where the file was downloaded. Enter this command:

bash dwagent.sh

Select “Run,” click on “Next”:

View on the Linux Workstation:

Accessing the Linux workstation from the dwservice.net site

Visit the dwservice.net site:

https://dwservice.net

Enter the username and password displayed on the Linux workstation running the dwservice.net client, click on “Sign in”:

Resources available on the Linux workstation

This page shows the resources available on the Linux workstation:

Screen (remote desktop)

Remote control of the desktop of the Linux workstation:

Files and Folders

Access to the filesystem on the Linux workstation:

Shell

Access to the operating system shell prompt on the Linux workstation:

Installing the dwservice.net client on a Linux workstation to enable unattended access

Open a terminal window on the Linux desktop. Change to the folder where the file was downloaded.

Use “sudo su” to become root if you have not already done so. enter these commands:

Enter this command:

bash dwagent.sh 

Select “Install,” click on “Next”:

Click on “Next”:

Select “Yes,” click on “Next”:

Enter the username and password of a valid dwservice.net account in the “DWS user” and DWS password” fields. Enter a name to describe the workstation in the “Agent name” field. Click on “Next”:

Click on “Close”:

Visit the dwservice.net site:

https://dwservice.net

Enter the username and password of a valid dwservice.net account in the “DWS user” and DWS password” fields. Click on “Sign in”:

Click on “Agents”:

Click on the icon for the Linux workstation:

Resources available on the Linux workstation

This page shows the resources available on the Linux workstation:

Screen (remote desktop)

Remote control of the desktop of the Linux workstation:

Files and Folders

Access to the filesystem on the Linux workstation:

Shell

Access to the operating system shell prompt on the Linux workstation:

Previous step: Chapter 14: Installing and configuring Live Helper Chat to add text chat support to a website
Next step: Chapter 16: Using a script to automate the creation of a virtual host on an Apache web server

Web presence step by step Chapter 14: Installing and configuring Live Helper Chat to add text chat support to a website

Previous step: Chapter 13: Installing and configuring MyBB to create a community forum site
Next step: Chapter 15: Using dwservice.net to provide remote technical support as an alternative to TeamViewer

Web presence step by step is a series of posts that show you to how to build a web presence.

In this chapter we install and configure Live Helper Chat to add text chat support to a website.

Installing the php-curl and php-bcmath extensions, enabling the Apache headers module, and restarting the Apache web server

Live Helper Chat requires the php-curl library, the php-bcmath library, and the headers Apache module.

Use an SSH terminal program to connect to the Ubuntu Linux cloud server you created in Chapter 3: Buying an Ubuntu Linux cloud server from Digital Ocean.

Enter these commands:

apt install php-curl php-bcmath
a2enmod headers
apachectl restart

Creating the MySQL database that will store data for the Live Helper Chat software

Enter this command:

mysql -u root -P

In the MySQL console, enter these commands (where ‘xxxxxx’ is your password):

create user lhc01@localhost;
set password for lhc01@localhost = 'xxxxxx';
create database lhc01;
use lhc01;
grant all privileges on * to lhc01@localhost;
quit

Downloading the zip file containing the Live Helper Chat software

Visit this site:

https://livehelperchat.com

Click on “Download”:

Click on on the link below “Github – recommended link”:

The file downloads:

Extracting the contents of the zip file

If you need detailed instructions on how to uncompress zip files or rename directories on Windows, MacOS, or Linux

This chapter assumes that you have followed the steps in Chapter 8: Installing and configuring WordPress to create a website, and Chapter 9: Installing and configuring phpMyAdmin to manage MySQL databases. If you have not read those chapters, and you are not familiar with how to uncompress a zip file or rename a directory using your operating system, please consult those chapters.

Uncompressing the livehelperchat-master.zip file

We need to uncompress the livehelperchat-master.zip file:

Viewing the extracted folders and files

We can see the lhc_web directory:

Using FileZilla to upload the lhc_web directory to the directory containing the documents for your website

We will use the FileZilla file transfer program to upload the directory “lhc_web” to the directory containing the documents for your website.

If you need detailed instructions on how to install and use FileZilla on Windows, MacOS, or Linux

This chapter assumes that you have read Chapter 7: Configuring the SSH server on an Ubuntu Linux cloud server to limit SFTP directory visibility within chroot jail directories, or that you are familiar with the FileZilla file transfer program.

Using Filezilla, connect to the Ubuntu Linux cloud server you created in Chapter 3: Buying an Ubuntu Linux cloud server from Digital Ocean. On the right (remote) side, select the directory that contains the documents for your website. On the left (local) side, select the directory that contains the “lhc_web” directory. Right-click or command-click on the directory, select Upload:

The transfer completes:

Installing the Live Helper Chat software using the Live Helper Chat installation wizard

For our example domain, we will visit:

https://linuxstepbystep.com/lhc_web/index.php/site_admin/install/install

(substitute your domain name)

Click “Next”:

Complete the fields as shown. Click “Next”:

Complete the field as shown below. Click “Finish installation”:

Click “Login here”:

Generating the Live Helper Chat JavaScript text to add to an HTML header

(Note: for our example domain, we can visit this site at https://linuxstepbyste.com/lhc_web/index.php/site_admin)

Enter your username and password. Click “Login”:

Click on “Settings”:

Under “Mobile,” click on “Settings”:

Select the checkbox “Enable notifications,” click on “Save”:

Click on “Settings”:

Click on “Embed code”:

Click on “Widget embed code (new):

Complete the fields and select the options as required for your site. Copy the code from the text area to the page where you would like the web chat window to appear:

Embedding Live Helper Chat in a WordPress site

To embed the Live Helper Chat application in a WordPress site, we must first install the Insert Headers and Footers plugin for WordPress.

Installing the Insert Headers and Footers WordPress plugin

In your WordPress control panel, click on “Plugins,” then click on “Add New”:

In the search window, enter the text “insert headers and footers,” locate the plugin “Insert Headers and Footers,” click on “Install Now”:

Click on “Activate”:

Click on “Settings,” then click on “Insert Headers and Footers”:

Adding the JavaScript code using the Insert Headers and Footers WordPress plugin

Complete the fields as shown.

Scroll to the bottom of the page. Paste the JavaScript code you generated earlier in the section “Generating the Live Help Chat JavaScript text to add to an HTML header” to the field “Scripts in Footer,” click “Save”:

Cick on “Visit Site”:

The chat window is visible on the WordPress site:

Texting between the site’s visitors and the site’s operators:

Embedding Live Helper Chat in a simple web page

We can add the Live Helper Chat text chat window to a simple web page.

Using an SSH terminal program, connect to your Ubuntu Linux cloud server. Change to the directory containing the documents for your website. Enter the command:

nano test.html

Paste the JavaScript code you generated in the section “Generating the Live Help Chat JavaScript text to add to an HTML header,” press Control-X to save and exit the file:

Enter these commands (where username is the username that owns the documents for the website):

chown username:username test.html
chmod 755 test.html

View the test.html page in a web browser:

Accessing the Live Helper Chat operator panel

For our example domain, we can visit this site at https://linuxstepbyste.com/lhc_web/index.php/site_admin (Substitute your domain name.)

Enter your username and password. Click “Login”:

Click on “Chat”:

Configuring and Using the Android client

Download the “Live Helper Chat” app from the Google Play Store. When you launch the application, you will see this screen. Click on “+”:

Complete the fields below as shown (substitute your domain name). Click “Login”:

Configuring and using the iOS client

Download the “Live Helper Chat” app from the Apple App Store. When you launch the application, you will see this screen. Click on “Allow”:

Click on “+”:

Complete the fields as shown (substitute your domain name). Click “Login”:

Previous step: Chapter 13: Installing and configuring MyBB to create a community forum site
Next step: Chapter 15: Using dwservice.net to provide remote technical support as an alternative to TeamViewer

Web presence step by step Chapter 13: Installing and configuring MyBB to create a community forum site

Previous step: Chapter 12: Installing and configuring the WooCommerce plugin for WordPress to enable a shopping cart for transactions
Next step: Chapter 14: Installing and configuring Live Helper Chat to add text chat support to a website

Web presence step by step is a series of posts that show you to how to build a web presence.

In this chapter, we install and configure MyBB to create a community forum site.

If you are not familiar with SSH terminal programs

This chapter assumes that you have read Chapter 4: Using an SSH terminal program to connect to an Ubuntu Linux cloud server. If you are not familiar with SSH terminal programs, please consult that chapter.

Creating a MySQL database to host the data for the MyBB community forum site

Use an SSH terminal program to connect to the Ubuntu Linux cloud server you created in Chapter 3: Buying an Ubuntu Linux cloud server from Digital Ocean.

From the system prompt, enter the command:

mysql -u root -p

From the MySQL console prompt, enter these commands (use a unique password in place of ‘xxxxxx’):

create user bb01@localhost;
set password for bb01@localhost = 'xxxxxx';
create database bb01;
use bb01;
grant all privileges on * to bb01@localhost;
quit

Installing the php-gd extension

In order to generate graphics representing captchas, we need to install the php-gd extension.

Enter the command:

apt install php-gd

Enter the command:

systemctl restart apache2

Configuring a Gmail account to allow MyBB to send email messages

We need to select or create a Gmail account that the MyBB community forum software will use to send email messages. This can be the same Gmail account you selected or created in Chapter 11: Installing and configuring the WP Mail SMTP plugin for WordPress to enable WordPress to send email messages.

Click on the settings icon (gear symbol in upper-right):

Click on “See all settings”:

Click on “Accounts and Import”:

Click on “Other Google Account settings”:

Click on “Security”:

In the section “Less secure app access,” click on “Turn on access (not recommended)”:

Enable the control so that the page displays “Allow less secure apps: ON”:

Click on “Forwarding and POP/IMAP,” select the option “Enable IMAP,” click on “Save Changes”:

Downloading the MyBB zip file

Visit this site:

https://mybb.com/download/

Click on “Download MyBB x.x.xx” (where x.x.xx is the version):

The file downloads:

If you are using Chrome, right-click or command-click on the name of the file, select “Show in folder”:

Uncompressing the MyBB zip file and renaming the Upload directory

If you need detailed instructions on how to uncompress zip files or rename directories on Windows, MacOS, or Linux

This chapter assumes that you have followed the steps in Chapter 8: Installing and configuring WordPress to create a website, and Chapter 9: Installing and configuring phpMyAdmin to manage MySQL databases. If you have not read those chapters, and you are not familiar with how to uncompress a zip file or rename a directory using your operating system, please consult those chapters.

Uncompressing the mybb_xxxx.zip file

We need to uncompress the mybb_xxxx.zip file:

Uncompressing the zip file extracts 2 directories: “Documentation,” and “Upload”:

Renaming the directory named “Upload” to “community”

Rename the “Upload” directory to “community”:

Using FileZilla to upload the community directory to the directory containing the documents for your website

We will use the FileZilla file transfer program to upload the directory renamed as “community” to the directory containing the documents for your website.

If you need detailed instructions on how to install and use FileZilla on Windows, MacOS, or Linux

This chapter assumes that you have read Chapter 7: Configuring the SSH server on an Ubuntu Linux cloud server to limit SFTP directory visibility within chroot jail directories, or that you are familiar with the FileZilla file transfer program.

Using Filezilla, connect to the Ubuntu Linux cloud server you created in Chapter 3: Buying an Ubuntu Linux cloud server from Digital Ocean. On the right (remote) side, select the directory that contains the documents for your website. On the left (local) side, select the directory that contains the “community” directory. Right-click or command-click on the directory, select Upload:

The transfer completes:

Installing the MyBB software using the MyBB installation wizard

For our example domain, we will visit:

https://linuxstepbystep.com/community

(substitute your domain name)

Click “Next”:

Click “Next”:

Click “Next”:

Complete the fields as show below. Click “Next”:

Scroll to the bottom of the web page. Click “Next”:

Click “Next”:

Click “Next”:

Complete the fields as show below. Click “Next”:

Complete the fields as show below. Click “Next”:

This screen will display when we have finished:

Visiting the community forum site

For our example domain, we will visit:

https://linuxstepbystep.com/community

(substitute your domain name)

Logging into the admin account

Enter the username and password for the admin user. Click “Login”:

Click on “Admin CP”:

Enter the username and password for the admin user. Enter the secret PIN. Click “Login”:

Configuring the MyBB community forum site

Click on “Configuration”:

Scroll towards the bottom of the web page:

Click on “Mail Settings”:

Configure settings for “Mail handler”

Mail handler: select "SMTP mail"
SMTP hostname: smtp.gmail.com
SMTP port: 587
SMTP username: the address of the gmail account you selected or created earlier in this procedure
SMTP Encryption Mode: select "TLS encryption"

Click “Save Settings”:

Click on “Login and Registration Options”:

For “Registration Method,” select “Send Email Verification”:

Scroll to the bottom of the web page. Click on “Save Settings”:

Registering as a new user on the community forum site

Use a web browser to visit the community forum site. Click on “Register.” On the page titled “Registration Agreement,” consider then if you decide click “I agree”:

Complete the fields as show in the example below. Click “Submit Registration!”:

MyBB displays this message:

Check the email account you provided during registration. View the message sent by MyBB community forum site:

To activate your account, click on the link in the email:

Welcome as a member:

We will create a post. Click on “My Forum”:

Click on “Post Thread”:

In the field “Thread Subject:” enter a subject.

In the field “Your Message:” enter the text of a message.

Click on “Post Thread”:

The message is displayed. Click on “My Category”:

We now have 1 thread and 1 post:

Previous step: Chapter 12: Installing and configuring the WooCommerce plugin for WordPress to enable a shopping cart for transactions
Next step: Chapter 14: Installing and configuring Live Helper Chat to add text chat support to a website

Forwarding ports to a KVM guest using iptables and Network Address Translation (NAT)

This post describes how to create a BASH script that opens the KVM virtual network adapter to outside traffic, and forwards ports from the KVM host to the KVM guest using iptables and Network Address Translation (NAT).

The KVM virtual network adapter rejects packets from the outside world by default

By default, the virtual network adapter for KVM (virbr0) is configured to block network traffic originating from outside the host computer. This can be resolved with iptables directives, which will be described below.

You do not need to use /etc/ufw/before.rules or /etc/libvirt/hooks/qemu to forward ports to a KVM guest

Many Internet articles and posts on this subject give the incorrect impression that the only way to forward ports to a KVM guest is via UFW and its /etc/ufw/before.rules file, and/or that you need to create a post-configuration script as a qemu “hook” in the /etc/libvirt/hooks/qemu file. You can open the virtual network adapter to outside traffic and forward ports to the KVM guest under NAT solely using iptables directives.

An example of a BASH script that opens the virtual adapter to outside traffic, and forwards ports from the host to the guest

To illustrate the solution, here is a sample BASH script that contains iptables directives that open the virtual adapter to outside traffic, and forwards ports 80/tcp, 443/tcp, and 8022/tcp from the host to the guest.

A note about the source code view below

For formatting reasons, the text is limited to a fixed width. To fully view the text, you can scroll to the right to see the ends of lines, or use the print view for this blog post.

#!/usr/bin/bash
# generated 2021/04/07 20:37:46 EDT by forwardportstoguestgenerator.php v0102
# Gordon Buchan https://gordonbuchan.com

# values
kvmsubnet="192.168.122.0/24"
wanadaptername="enx4ce1734b693e"
wanadapterip="192.168.46.123"
kvmadaptername="virbr0"
kvmadapterip="192.168.122.174"

# allow virtual adapter to accept packets from outside the host
iptables -I FORWARD -i $wanadaptername -o $kvmadaptername -d $kvmsubnet -j ACCEPT
iptables -I FORWARD -i $kvmadapterip -o $wanadaptername -s $kvmsubnet -j ACCEPT
# forward ports from host to guest
iptables -t nat -A PREROUTING -i $wanadaptername -d $wanadapterip -p tcp --dport 80 -j  DNAT --to-destination $kvmadapterip:80
iptables -t nat -A PREROUTING -i $wanadaptername -d $wanadapterip -p tcp --dport 443 -j DNAT --to-destination $kvmadapterip:443
iptables -t nat -A PREROUTING -i $wanadaptername -d $wanadapterip -p tcp --dport 8022 -j DNAT --to-destination $kvmadapterip:22

A PHP script that generates a BASH script that opens the virtual network adapter to outside traffic, and forwards ports from the host to the guest

This script runs the ifconfig and virsh commands to compile lists of possible WAN interfaces and KVM guests. This script prompts for choices at console, and generates a text file containing a BASH script with iptables directives that open the virtual adapter to outside traffic, and forward ports from the host to the guest using network address translation (NAT).

A note about the source code view below

For formatting reasons, the text is limited to a fixed width. To fully view the text, you can scroll to the right to see the ends of lines, or use the print view for this blog post.

To view the source code in an another text editor, download and uncompress the zip file described below, or select and copy the text from the source code example below, and paste the text into a file on your computer called “forwardportstoguest.php”

Consider copying the file to your Apache web server’s /usr/bin directory with a chmod of 755 so that it can be executed from the system path. Steps to do so are included in the procedure below.

Saving the PHP script to a file called forwardportstoguestgenerator.php

Download this zip file:

https://blog.gordonbuchan.com/files/forwardtoguest0102.zip

Uncompress the zip file to extract the file “forwardportstoguestgenerator.php” then copy the file to your KVM host computer.

or

Select and copy the text from the source code example above, and paste the text into a file on your computer called “forwardportstoguestgenerator.php”

#!/usr/bin/php
<?PHP
// forwardportstoguestgenerator.php
// v0102
// scan ifconfig and virsh, create iptables directives to forward ports to kvm guests
// chmod this script 755 to run as ./forwardportstoguestgenerator.php or run with php forwardportstoguestgenerator.php
// writes to a text file the BASH script forwardportstoguestscript.sh
 
// 2021/04/07
// Gordon Buchan https://gordonbuchan.com
// MIT license https://mit-license.org
 
// overview
// run the command "ifconfig" to isolate potential wan adapter names and ip addresses
// infer the KVM subnet based on the first 3 sections of the ip address of the "virbr0" adapter
// run the command "virsh net-dhcp-leases default" to isolate potential kvm guest names and ip addresses
// ask client to choose WAN adapter
// ask client to choose KVM guest
// create a batch file containing iptables directives to open the virtual adapter to packets from outside the host
// and to forward ports from the host adapter to the KVM guest adapter 80/tcp, and 443/tcp, 8022/tcp
 
// //////////////////////////////////////////////////////////////////////////////////
// start function sink
 
// str_contains() polyfill for pre PHP8
if (!function_exists('str_contains')) {
    function str_contains(string $haystack, string $needle): bool
    {
        return '' === $needle || false !== strpos($haystack, $needle);
    }
}
 
// end function sink
// //////////////////////////////////////////////////////////////////////////////////
 
// start get the WAN adapter names and ip addresses
 
// capture output of ifconfig command to variable $ifcstr
$ifcstr = `ifconfig`;
 
// convert string $ifcstr to array of lines $ifcstrarr
// use linefeed as field delimiter in array population
$ifcstrarr = explode("\n",$ifcstr);
 
// count lines in the array
$ifcstrarrnumlines = count($ifcstrarr);
 
$adnamestrarr = array();
$adipstrarr = array();
 
$kvmsubnet = "";
 
// iterate through array of lines
for ( $i=0;$i<$ifcstrarrnumlines;$i++) {
 
    if ( str_contains($ifcstrarr[$i],"flags")) {
        $flagsstr = "flags";
        $flagsstrloc = strpos("$ifcstrarr[$i]", $flagsstr) - 2;
        $adnamestr = substr($ifcstrarr[$i],0,$flagsstrloc);
    } // close if str contains "flags"
 
    // we will eventually filter virbr0, but for now we can find out the subnet for the KVM guest network
 
    if ( str_contains($ifcstrarr[$i],"inet") && !str_contains($ifcstrarr[$i],"inet6") ) {
 
        $inetstr = "inet";
        $inetstrloc = strpos("$ifcstrarr[$i]",$inetstr) + 5;
        $adipstr = substr($ifcstrarr[$i],$inetstrloc,"20");
        $spacestrloc = strpos("$adipstr"," ");
        // trimming the variable
        $adipstr = substr($adipstr,0,$spacestrloc);
 
        if (str_contains($adnamestr,"virbr0")) {
            // start infer KVM subnet
            // //////////////////////////////////////////////////////////
            // do stuff here to get the virbr0 ip address so we can infer subnet
            $kvmsubnetraw = $adipstr;
            $lastdotloc = strrpos($kvmsubnetraw,".");
            $kvmsubnet = substr($kvmsubnetraw,0,$lastdotloc) . ".0/24";
            echo "\nKVM subnet\nkvmsubnet: $kvmsubnet\n\n";
            // end infer KVM subnet
            // //////////////////////////////////////////////////////////
        } else {
            // stuff the arrays they will match by number because done at same time
            // filter for loopback device
            if (!($adipstr == "127.0.0.1")) {
                $adnamestrarr[] = $adnamestr;
                $adipstrarr[] = $adipstr;
            }
        }
 
    } // close if str contains "inet"
 
} // end for $i
 
//so we are always defined
$adnamestrarrnumlines = "";
$adnamestrarrnumlines = count ($adnamestrarr);
if (!$adnamestrarrnumlines) {
    echo "no WAN adapters found.\nStopping.\n";
    exit();
}

// if we do not have a KVM subnet, then something is wrong. Stop.
if (!$kvmsubnet) {
    echo "KVM subnet not detected. Stopping.\n";
    exit();
}
 
// end get the WAN adapter names and ip addresses
// //////////////////////////////////////////////////////////////////////////////////
 
// start get the KVM guest names and ip addresses
 
// capture output of virsh command to variable $ifcstr
$virshleastr = `virsh net-dhcp-leases default`;
 
// convert string $virshleastr to array of lines $virshleastrarr
// use linefeed as field delimiter in array population
$virshleastrarr = explode("\n",$virshleastr);
 
// count lines in the array
$virshleastrarrnumlines = count($virshleastrarr);
 
$kvmnamestrarr = array();
$kvmipstrarr = array();
 
// iterate through array of lines
for ( $j=0;$j<$virshleastrarrnumlines;$j++) {
    if ( str_contains($virshleastrarr[$j],"ipv4")) {
        $ipv4str = "ipv4";
        $ipv4strloc = strpos("$virshleastrarr[$j]", $ipv4str) + 11;
        $kvmlinestr = substr($virshleastrarr[$j],$ipv4strloc,50);
        $slashstr = "/";
        $slashstrloc = strpos("$kvmlinestr",$slashstr);
        $kvmipstr = substr($kvmlinestr,0,$slashstrloc);
        $kvmnamestr = substr($kvmlinestr,$slashstrloc+5,12);
        $kvmnamestr = trim($kvmnamestr);
        //stuff the arrays they will match by number because done at same time
        $kvmnamestrarr[] = $kvmnamestr;
        $kvmipstrarr[] = $kvmipstr;
    } // close if str contains "ipv4"
} // end for $j
 
$kvmnumlines = count ($kvmnamestrarr);
if (!$kvmnumlines) {
    echo "no VM guest DHCP leases found. Please start a VM.\nStopping.\n";
    exit();
}

// end get the KVM guest names and ip addresses
// //////////////////////////////////////////////////////////////////////////////////
 
// start ask client to choose WAN adapter
 
// show the possible WAN adapters as a numbered list to console:
echo "WAN adapters\n";
for ($k=0;$k<$adnamestrarrnumlines;$k++) {
    $displaynum = $k + 1;
    echo "$displaynum. $adnamestrarr[$k] $adipstrarr[$k]\n";
}
 
echo "\n";
 
// use readline function to ask questions interactively
// trap function in a while condition for sanity checking on input until satisfied
$wananswer = "";
while (!$wananswer || ($wananswer>$displaynum) || !is_numeric($wananswer) ) {
    $wananswer = readline("Please choose a WAN adapter (1-$displaynum): ");
}
 
echo "choice entered: $wananswer\n";
 
// because humans start at 1 and computers start at 0
$wanchoiceminus = $wananswer - 1;
 
$wanadaptername = $adnamestrarr[$wanchoiceminus];
$wanadapterip = $adipstrarr[$wanchoiceminus];
 
echo "\n";
echo "wanadaptername: $wanadaptername\n";
echo "wanadapterip: $wanadapterip\n";
echo "\n";
 
// end ask client to choose WAN adapter
// //////////////////////////////////////////////////////////////////////////////////
 
// start ask client to choose KVM guest
 
// show the possible KVM guests as a numbered list to console:
echo "KVM guests\n";
echo "(hint: if a VM is not listed here, start the VM so it gets a DHCP lease)\n";
for ($m=0;$m<$kvmnumlines;$m++) {
    $displaynum = $m + 1;
    echo "$displaynum. $kvmnamestrarr[$m] $kvmipstrarr[$m]\n";
}
 
echo "\n";
 
// use readline function to ask questions interactively
// trap function in a while condition for sanity checking on input until satisfied
$kvmanswer = "";
while (!$kvmanswer || ($kvmanswer>$displaynum) || !is_numeric($kvmanswer) ) {
    $kvmanswer = readline("Please choose a KVM guest (1-$displaynum): ");
}
 
echo "choice entered: $kvmanswer\n";
 
// because humans start at 1 and computers start at 0
$kvmchoiceminus = $kvmanswer - 1;
 
// we should not confuse kvm guest name with kvmadaptername
// we hardcode the name of the kvm adapter as the string "virbr0"
$kvmadaptername = "virbr0";
$kvmadapterip = $kvmipstrarr[$kvmchoiceminus];
 
echo "\n";
echo "kvmadaptername: $kvmadaptername\n";
echo "kvmadapterip: $kvmadapterip\n";
echo "\n";
 
// end ask client to choose KVM guest
// //////////////////////////////////////////////////////////////////////////////////
 
// start engine section
 
// construct the string variable containing the contents of the script file
 
$timestring = date("Y/m/d H:i:s T");
 
// start from nothing
$scriptcontents = "";
 
$scriptcontents .= "#!/usr/bin/bash\n";
$scriptcontents .= "# generated $timestring by forwardportstoguestgenerator.php v0102\n";
$scriptcontents .= "# Gordon Buchan https://gordonbuchan.com\n";
$scriptcontents .= "\n";
$scriptcontents .= "# values\n";
$scriptcontents .= "kvmsubnet=\"$kvmsubnet\"\n";
$scriptcontents .= "wanadaptername=\"$wanadaptername\"\n";
$scriptcontents .= "wanadapterip=\"$wanadapterip\"\n";
$scriptcontents .= "kvmadaptername=\"$kvmadaptername\"\n";
$scriptcontents .= "kvmadapterip=\"$kvmadapterip\"\n";
$scriptcontents .= "\n";
$scriptcontents .= "# allow virtual adapter to accept packets from outside the host\n";
$scriptcontents .= "iptables -I FORWARD -i \$wanadaptername -o \$kvmadaptername -d \$kvmsubnet -j ACCEPT\n";
$scriptcontents .= "iptables -I FORWARD -i \$kvmadapterip -o \$wanadaptername -s \$kvmsubnet -j ACCEPT\n";
$scriptcontents .= "# forward ports from host to guest\n";
$scriptcontents .= "iptables -t nat -A PREROUTING -i \$wanadaptername -d \$wanadapterip -p tcp --dport 80 -j  DNAT --to-destination \$kvmadapterip:80\n";
$scriptcontents .= "iptables -t nat -A PREROUTING -i \$wanadaptername -d \$wanadapterip -p tcp --dport 443 -j DNAT --to-destination \$kvmadapterip:443\n";
$scriptcontents .= "iptables -t nat -A PREROUTING -i \$wanadaptername -d \$wanadapterip -p tcp --dport 8022 -j DNAT --to-destination \$kvmadapterip:22\n";
 
$scriptfilename = "forwardportstoguestscript.sh";
 
# write the text file
$fh = fopen("$scriptfilename","w");
$filesuccess = fwrite($fh,$scriptcontents);
fclose($fh);
 
if ($filesuccess) {
    echo "SUCCESS script written to file: $scriptfilename\n";
    chmod("$scriptfilename", 0755);
    $scriptperms = substr(sprintf('%o', fileperms("$scriptfilename")), -4);
    echo "scriptperms: $scriptperms\n";
    if ($scriptperms == "0755") {
        echo "SUCCESS chmod 755 $scriptfilename successful.\n";
    } else {
        echo "ERROR chmod 755 not $scriptfilename not successful.\n";
    }
} else {
    echo "ERROR script not written to file: $scriptfilename\n";
}
 
// end engine section
// /////////////////////

Executing as root

If you have not logged in as root, please escalate to root.

Enter this command:

sudo su

Installing php cli and net-tools

The PHP script requires the php cli and the ifconfig command from net-tools. The script also requires virsh, but you likely have that tool installed already if you are hosting KVM guests.

Ubuntu

Enter the command:

apt install php7.4-cli net-tools

Fedora

Enter the command:

dnf install php-cli net-tools

Executing the PHP script forwardportstoguestgenerator.php to generate the BASH script forwardportstoguestscript.sh

Enter the command:

php forwardportstoguestgenerator.php

When prompted, choose a WAN adapter and a KVM guest.

You will see output similar to the following:

root@server:/usr/bin# php forwardportstoguestgenerator.php
KVM subnet
kvmsubnet: 192.168.122.0/24
WAN adapters
1. enx4ce1734b693e 192.168.46.123
2. wlp0s20f3 192.168.46.103
Please choose a WAN adapter (1-2): 1
choice entered: 1
wanadaptername: enx4ce1734b693e
wanadapterip: 192.168.46.123
KVM guests
(hint: if a VM is not listed here, start the VM so it gets a DHCP lease)
1. midland 192.168.122.174
Please choose a KVM guest (1-1): 1
choice entered: 1
kvmadaptername: virbr0
kvmadapterip: 192.168.122.174
SUCCESS script written to file: forwardportstoguestscript.sh
scriptperms: 0755
SUCCESS chmod 755 forwardportstoguestscript.sh successful.

Executing the BASH script forwardportstoguestscript.sh

Enter the command:

bash forwardportstoguestscript.sh

Testing the forwarded ports

Using a different workstation on the network, connect to the IP address of the computer hosting the KVM guest.

If you have forwarded the public-facing ports on your router to the IP address of the computer hosting the KVM guest, test whether traffic on the ports is forwarded to the KVM guest.