Introduction

I am a PHP developer. I use Linux, Apache, MySQL, and PHP to further that goal.

This video/article will show how to create a self signed SSL on a test virtual machine running on a private IP with a non-routable domain name with the Top Level Domain (TLD) of .internal.

I only use self signed SSL’s for my test servers that I have created. For production I use Let’s Encrypt.

The steps below will show how to create a self signed SSL certificate for a  virtual host. Using these instruction each virtual server will have it’s own certificate.

I include the instructions for configuring the secured Apache configuration including PHP-FPM. If you are not using PHP-FPM you can remove that code from the Apache secured configuration as provided.

Prerequisites

• • Access to a web server via SSH.
  • A user capable of becomming sudo.

Overview

You’ll:

1. Create a self-signed certificate for one <-domain.tld-> , in my case that will be ‘lamp.internal’.  The Top Level Domain (TLD) of .internal is not publicly routable.
2. Configure one virtual host for one domain using the cert.
3. Enable the virtual host in Apache.

Step 1. Create Self-Signed Certificates

For each domain, <-domain.tld-> (use the domain name and TLD that you desire), run:

• • sudo mkdir -p /etc/ssl/internal/<-domain.tld->
  • sudo openssl req -x509 -nodes -days 825 -newkey rsa:2048 \
    -keyout /etc/ssl/internal/<-domain.tld->/<-domain.tld->.key \
    -out /etc/ssl/internal/<-domain.tld->/<-domain.tld->.crt \
    -subj “/C=<-YourCountryCode->/ST=<-YourState->/L=<-YourCity->/O=<-YourCompany->/OU=<-YourDepartment->/CN=<-domain.tld->”

Replace

• • <-domain.tld-> with your domain.
  • <-YourCountryCode-> with your company code.
  • <-YourState-> with your state.
  • <-YourCity-> with your city.
  • <-YourCompany-> with your company.
  • <-YourDepartment-> with your department.

Step 2. Create Apache Virtual Host Config

Create a file like /etc/apache2/sites-available/<-domain.tld-ssl->.conf with the following contents.

• • sudo vi /etc/apache2/sites-available/<-domain.tld-ssl->.conf

<VirtualHost *:443>
    ServerName <-domain.tld->
    ServerAlias www.<-domain.tld-> # if you are configuring your virtual host to redirect to <-www.domain.tld-> you will need this directive.
    DocumentRoot /var/www/<-domain.tld->/public_html

    SSLEngine on
    SSLCertificateFile /etc/ssl/internal/<-domain.tld->/<-domain.tld->.crt
    SSLCertificateKeyFile /etc/ssl/internal/<-domain.tld->/<-domain.tld->.key

    # mod_rewrite
    # .htaccess has the other needed mod_rewrite code
    <Directory /var/www/<-domain.tld->/public_html/>
        Options Indexes FollowSymLinks
        AllowOverride All
        Require all granted
    </Directory>

    # Start PHP-FPM
    # This is the PHP-FPM code. If you are not running PHP-FPM you can comment out or remove.
    # Adjust PHP socket version if needed.
    <FilesMatch \.php$>
        SetHandler "proxy:unix:/var/run/php/php8.3-fpm.<-php-fpm-user->.sock|fcgi://localhost/"
    </FilesMatch>
    # End PHP-FPM

    ErrorLog ${APACHE_LOG_DIR}/<-domain.tld->.error.log
    CustomLog ${APACHE_LOG_DIR}/<-domain.tld->.access.log combined

</VirtualHost>

Step 3 Enable SSL and Site

• • sudo a2enmod ssl
  • sudo a2ensite <-domain.tld-ssl->.conf.
  • sudo systemctl reload apache2

Step 4. Add Domain to /etc/hosts file

• • sudo vi /etc/hosts
  • hit the i key to put vi in insert mode
  • add a line return
  • Enter the IP of the server, then a tab, then <-domain.tld->
  • Enter the IP of the server, then a tab, then www.<-domain.tld->
  • Press the escape key to exit insert mode
  • Press the colon key
  • Press the q key followed by the w key, followed by the enter key
  • These steps will configure the local virtual server.
  • In my case the Virtual host resides on VirtualBox that is installed on a Windows 10 laptop so the Windows host file needs to be updated as well.
  • To update the Windows host file:
    • Launch as notepad as administrator by right mouse clicking on notepad and selecting “Run as administrator”.
    • From the top menu click on Open.
    • Travers to Windows->System32->drivers->etc.
    • In the lower right of the dialog  box set the file exnstention to “All Files (*.*).
    • Click on the file hosts.
    • Scroll to the bottom and press return to obtain a new line.
    • Press the tabb key, enter the domain followed by another tab then enter the domain name.
    • From the main file click on File, Select save and exit the diaolg pager.
  •  If you are on a Linux Desktop then you will need to update that Linux box’s /etc/host file:
    • At the command line enter “sudo vi /etc/hosts
    • hit the i key to put vi in insert mode
    • add a line return
    • Enter the IP of the server, then a tab, then <-domain.tld->
    • Enter the IP of the server, then a tab, then www.<-domain.tld->
    • Press the escape key to exit insert mode
    • Press the colon key
    • Press the q key followed by the w key, followed by the enter key

Step 5. Verify the Apache Configuration

• • sudo apache2ctl configtest
  • Should Return : Syntax OK

Step 6. Verify SSL Certificate:

Use openssl to test:

echo -e "GET / HTTP/1.1\r\nHost: <-domain.tld->\r\nConnection: close\r\n\r\n" | openssl s_client -connect <-domain.tld->:443 -servername <-domain.tld-> -quiet

Look for:

• • Verify return code: 0 (ok)
  • verify error:num=18:self-signed certificate : this is normal.
  • Run : sudo apache2ctl configtest – which will return “Syntax OK”

Step 7. Check with a Browser:

• • Visit https://<-domain.tld-> to verify. (ensure it is https)
  • Since this is self signed, there will be an SSL warning.

Since I am doing this for PHP development and for testing, all my websites are on a local web server that is on a private domain. To resolve my non-routable domain names, I use the Windows and Linux hosts files as a simple domain name system (DNS). If I am using the private IP range of 192.168.1.001 to 192.168.1.253 and I configure my server to use the IP 192.168.1.55 I would add “192.168.1.55<tab><-domain.tld->” to the Windows and Linux hosts files.

When accessing this private server that is configured with a self-signed cert, your browser will show a warning — you can proceed manually.

To create more self-signed certificates for other virtual hosting accounts just repeat these instruction.

Conclusion

That’s it. With this setup, I can easily create self-signed SSL certificates for any of my test environments running on private, non-routable Top Level Domain (TLD). Each virtual host gets its own certificate, and the Apache configuration can be reused and tweaked as needed — especially if you’re using PHP-FPM. This is how I like to keep my development environments secure and consistent without relying on external certificate authorities. For production, I always use Let’s Encrypt — but for local testing, this works just fine.

To view Apache 2 logs on Ubuntu, you can look in the /var/log/apache2 directory.

Here are the common log files you’ll want to check:

Access Logs

These logs contain information about requests that come to the Apache server. This log can contain client IP, requested URL, response status, and more.

Path: /var/log/apache2/access.log

View: sudo tail -f /var/log/apache2/access.log

Error Logs

This log file records any errors Apache encounters, including server misconfigurations, failed requests, or issues with the application running on the server.

Path: /var/log/apache2/error.log

View: sudo tail -f /var/log/apache2/error.log

Other Logs (Virtual Hosts)

If you’re using virtual hosts (for different websites hosted on the same server), you might have separate logs for each virtual host. These logs would be inside a subdirectory under “/var/log/apache2/”, such as “/var/log/apache2/your-site-name-access.log” and “/var/log/apache2/your-site-name-error.log“.

To actively monitor Apache logs, you can use “tail -f” to follow the logs in real-time. If you’re debugging something, this is very helpful.

Conclusion

Apache only has a few log files. For virtual host you will find logs for each virtual host. These normally come in the format of /var/log/apache2/your-site-name-access.log and /var/log/apache2/your-site-name-error.log.

In Ubuntu Linux, logs are typically stored in the “/var/log/” directory. These logs can provide insights into system events, errors, and other important information. Here are some of the key log files and their uses:

auth.log

/var/log/auth.log: This log contains authentication-related events, such as login attempts and sudo commands.

To view: sudo less /var/log/auth.log

dmesg.log

/var/log/dmesg: This log stores kernel messages, which include hardware information and system boot details.

To view: sudo less /var/log/dmesg

faillog

/var/log/faillog: faillog is a system utility that tracks failed login attempts.

To view: sudo less /var/log/faillog

kern.log

/var/log/kern.log: This file contains kernel messages and can help diagnose low-level system problems.

To view: sudo less /var/log/kern.log

php8.x-fpm.log

/var/log/php8.x-fpm.log: This log file contains log messages generated by PHP-FPM related to the operation of PHP scripts running through it.

To view: sudo less /var/log/php8.x-fpm.log

syslog.log

/var/log/syslog: This is the general system log. It contains messages related to system activity and applications, and it’s a good place to start for troubleshooting.

To view: sudo less /var/log/syslog

ufw.log

/var/log/ufw.log: This log file is where UFW (Uncomplicated Firewall) records information about the firewall’s activity.

To view: sudo less /var/log/ufw.log

Conclusion

These 7 Ubuntu Linux logs can be used for system monitoring, troubleshooting, security, auditing, and debugging.

 

 

Introduction

The Apache web server, serves content from a server to a browser. Apache is widely used on the the web. In this article I will cover most, if not all, of the Apache commands you will need to know.

Start Apache Service

• • sudo systemctl start apache2 # For Debian-based systems (Ubuntu)
  • sudo systemctl start httpd # For Red Hat-based systems (CentOS, Fedora)

Stop Apache Service

• • sudo systemctl stop apache2 # For Debian-based systems (Ubuntu
  • sudo systemctl stop httpd # For Red Hat-based systems (CentOS, Fedora)

Restart Apache Service

• • sudo systemctl restart apache2 # For Debian-based systems (Ubuntu)
  • sudo systemctl restart httpd # For Red Hat-based systems (CentOS, Fedora)

Reload Apache Configuration

• • sudo systemctl reload apache2 # For Debian-based systems (Ubuntu)
  • sudo systemctl reload httpd # For Red Hat-based systems (CentOS, Fedora)

Check Apache Status

• • sudo systemctl status apache2 # For Debian-based systems (Ubuntu)
  • sudo systemctl status httpd # For Red Hat-based systems (CentOS, Fedora)

Enable Apache to Start at Boot

• • sudo systemctl enable apache2 # For Debian-based systems (Ubuntu)
  • sudo systemctl enable httpd # For Red Hat-based systems (CentOS, Fedora)

Disable Apache to Start at Boot

• • sudo systemctl disable apache2 # For Debian-based systems (Ubuntu)
  • sudo systemctl disable httpd # For Red Hat-based systems (CentOS, Fedora)

Test Apache Configuration

• • apachectl configtest

Check Apache Version

• • apache2 -v # For Debian-based systems (Ubuntu)
  • httpd -v # For Red Hat-based systems (CentOS, Fedora)

Stop Apache Gracefully

• • sudo apachectl graceful

Run Apache in the Foreground (Debug Mode)

• • sudo apachectl -X

Disable a Site

• • sudo a2dissite [site-name] # For Debian-based systems (Ubuntu)

Enable a Site

sudo a2ensite [site-name] # For Debian-based systems (Ubuntu)

Check Apache Modules

apache2ctl -M # For Debian-based systems (Ubuntu)
httpd -M # For Red Hat-based systems (CentOS, Fedora)

Enable/Disable Apache Modules

sudo a2enmod [module_name] # Enable a module
sudo a2dismod [module_name] # Disable a module

Conclusion

These commands should help you effectively manage your Apache HTTP Server. Always ensure you have the proper permissions (often requiring sudo) to execute administrative actions.

Introduction

This article is an introduction to many Linux command line commands. Each command has one or more arguments which I did not include.

This is not a comprehensive list, however this list will get you well on your way.

Here are some fundamental Linux commands that are essential for everyday use:

File and Directory Management:

• • ls – List directory contents
  • cd – Change directory
  • pwd – Print working directory (shows the current directory)
  • mkdir – Make a new directory
  • rmdir – Remove an empty directory
  • rm – Remove files or directories
  • cp – Copy files or directories
  • mv – Move or rename files or directories
  • touch – Create an empty file or update the timestamp of a file

File Viewing and Editing:

• • cat – Display file contents
  • more / less – View file contents page by page
  • head – Display the first few lines of a file
  • tail – Display the last few lines of a file

File Permissions and Ownership:

• • chmod – Change file permissions
  • chown – Change file owner and group
  • chgrp – Change the group ownership of a file

System Information:

• • df – Display disk space usage
  • du – Show disk usage of files and directories
  • top – Display system processes
  • ps – Show running processes
  • free – Show memory usage
  • uptime – Show how long the system has been running
  • uname – Show system information

Package Management (Debian-based systems like Ubuntu):

• • apt-get – Package management tool

Searching:

• • find – Search for files in a directory hierarchy
  • grep – Search for text patterns within files

Networking:

• • ping – Test network connectivity
  • ifconfig (or ip a) – Show network interface configuration
  • netstat – Show network connections
  • scp – Secure copy (copy files over SSH)

Archive and Compression:

• • tar – Create and extract tar archives
  • zip / unzip – Compress or decompress files

Other Useful Commands:

• • sudo – Execute a command as a superuser
  • man – Show the manual for a command
  • history – Show the history of previously executed commands
  • alias – Create custom command shortcuts

Conclusion

In this article we cover a lot of the Linux command line commands. This may not be a comprehensive list of Linux command, however the contents of this article will get you well on your way to managing Linux from the command line.

Introduction

In this article and associated video, we will cover Linux file and directory ownership and permissions.

Every file and directory on a Linux system is associated with an owner and a group. This is how the system identifies who has control over the files and directories and who is part of the group that can access it.

• • Owner : The user who owns a file or directory. Customarily the owner has the ability to add/edit/delete files/directories and modify their permissions.
  • Group : A set of users who share the same permissions for a file or a directory.
  • Others : Everyone else who is not the owner or a member of the group.

1) Symbolic Notation : when permissions and users are represented by letters.

Permissions:

• • “r” : Read
  • “w” : Write
  • “x” : Execute
  • “+” : Add a permission
  • “–” : Remove a permission
  • “=” : Set exact permissions

Ownership:

• • Owner : u
  • Group : g
  • Others : o

Examples:

Add execute permission for the owner: $ chmod u+x file.txt

Remove write permission for others: $ chmod o-w file.txt

2) Numeric Notation

Each permission corresponds to a number:

• • “r = 4” : read
  • “w = 2” : write
  • “x = 1” : execute

The permissions for each user (owner, group, others) are represented as a three-digit number.

• • “7” = “rwx” (read, write, execute)
  • “6” = “rw-” (read, write)
  • “5” = “r-x” (read, execute)
  • “4” = “r–” (read)
  • “3” = “-wx” (write, execute)
  • “2” = “–w–” (read)
  • “1” = “–x” (execute)
  • “0” = “–––” (no permissions)

To set permissions numerically, you add the values for owner, group, and others. For example:

File : $ chmod 644 file.txt

• • “6” (owner) = `rw-` (read, write)
  • “4” (group) = `r–` (read)
  • “4” (others) = `r–` (read)

Directory : $ chmod 755 <directory>

• • “7” (owner) = `rwx` (read, write, execute)
  • “5” (group) = `r-x` (read, execute)
  • “5” (others) = `r-x` (read, execute)

3) File Ownership

• • Owner : The user who owns a file.
  • Group : A set of users who share the same permissions for a file.
  • Others : Everyone else who is not the owner or a member of the group.

4) File Permissions

• • Read (r) : Permission to open and read the contents of a file.
  • Write (w) : Permission to modify or delete the contents of a file.
  • Execute (x) : Permission to execute a file (i.e., run it as a program).

5) Directory Ownership

Owner (User): Each directory in Linux is associated with an owner, which is typically a user. The owner has specific permissions to read, write, and execute files within that directory, depending on the permissions set. The owner is usually the user who created the directory, but ownership can be changed.

Group : In addition to the owner, a directory is associated with a group. The group defines a set of users who share common access rights to the directory. Group members can have different permission levels compared to the owner or other users.

Permissions

Linux uses three main types of permissions for directories:

• • Read (r) : The user can list the contents of the directory.
  • Write (w) : The user can create, delete, or rename files in the directory.
  • Execute (x) : The user can navigate into the directory and access files or subdirectories.

These permissions are assigned to three categories of users:

• • Owner: The user who owns the directory.
  • Group: Users who are members of the group assigned to the directory.
  • Others: All other users on the system.

6) Directory Permissions

• • Read (r) : for directories, this allows listing the files inside the directory.
  • Write (w) : for directories, this allows adding, deleting, or renaming files within the directory.
  • Execute (x): for directories, this allows accessing the directory, meaning the ability to enter the directory and work with its file.

7) Changing Ownership

To change the owner and group of a file or directory, you use the `chown` command.

Example : $ sudo chown <newuser>:<newgroup> file.txt (could be a directory).

8) Changing Permissions

To modify the permissions, you use the “chmod” command. Permissions can be set using symbolic notation (letters) or numeric notation (numbers).

• • Read (“r”) : Allows listing the contents.
  • Write (“w”) : Allows modifying the directory’s contents (adding/removing files).
  • Execute (“x”) : Allows accessing files inside the directory (entering the directory).

Example: sudo chmod 755 <directory> (could be a file)

9) Listing Permissions

File: One the command line issue the command “vdir”.

Directories: One the command line issue the command “vdir -id”.

Conclusion

This article and associated video cover Linux file and directory ownership and permissions and how to change them.

Changing file ownership and permissions can be completed by one of two approaches – Symbolic Notation or Numeric Notation.

To change file or directory ownership we use the chown command.

To change file or directory permissions we use the chmod command.

What is Linux vi

vi is a powerful text editor that runs on Linux and UNIX systems, commonly used for editing configuration files, programming, and general text manipulation. It is known for its efficiency and speed once users are familiar with its commands.

vi is my editor of choice while I am connected to a web server via the Secure Shell (SSH). I am a PHP programmer and have a home lab that consists of using VirtualBox to create virtual machines. These virtual machines are web servers created for PHP development and testing. They are Linux, Apache, MySQL, and PHP (LAMP).

I use Ubuntu servers to create these LAMP web servers. Vi is one of the tools in my toolbox.

Why use vi?

Pre-installed: vi is usually available by default on almost all Linux distributions, making it convenient when working on servers or systems with minimal software installed.

Efficiency: vi allows advanced users to perform complex text editing tasks quickly and with precision.

Lightweight: It is a lightweight editor that consumes minimal system resources, which is ideal for working on remote servers or in environments with limited resources.

The best way to learn Vi is to create a new file and try it out for yourself.

1) VI Operates in Three Main Modes:

• • Normal Mode: This is the default mode. You can navigate and manipulate text using various commands.
  • Insert Mode: Add, Edit, Delete, and Copy text. Press the i key to activate insert mode. In insert mode, one can add, edit, delete, copy text, and move text around.
  • Command Mode: You enter this mode by pressing : (colon key) while in normal mode, to run commands like saving, quitting, or searching.

2) I Only Use a Subset of What is Available.

• • Type “vi <file-name>” on the command line to edit or create a file.
  • Pressing the “i” key switches us into Insert mode.
  • Pressing the “ESC” key switches us out of Insert mode into normal mode.
  • Pressing the “:” (colon) switches us into command mode.
  • dd command – Remove a line.
  • :q To quit when no changes have occurred.
  • :q! To not save changes.
  • :w Save and continue editing.
  • :wq To write (save) and quit (exit editing of file)
  • :set nu — Display line numbers.
  • :set nonu – Stop displaying line numbers.

3) Commands I Rarely or Never Use:

• • yy — Copy the current line. Referred to as yank(ed)
  • p — Paste the yanked line.
  • o — New line under the current line.
  • O — New line above the current line.
  • A — Append to the end of the line.
  • a — Append after the cursor’s current position.
  • I — Insert text at the beginning of the current line.
  • b — Go to the beginning of the word.
  • e — Go to the end of the word.
  • x — Delete a single character. (where the cursor is blinking)
  • dd — Delete the current line.
  • [number]dd — Delete X number of lines.
  • [number]yy — Yank X number of lines.
  • G — Go to the end of the file.
  • XG — Go to line X in a file.
  • gg — Go to the first line in a file.
  • h — Move left one character.
  • j — Move down one line.
  • k — Move up one line.
  • l — Move right one character.

Conclusion

Vi is the editor I like to use when connected to a remote server. I manage virtual web hosts on VirtualBox. Vi makes it easy to manage all the configurations a LAMP server contains.

In this article we learned that vi has Three Main Mode, is always available on Linux and Unix servers, and is easy to use once some of the features are understood.