When you attempt to VBoxLinuxAdditions.run script to install VirtualBox Guest Additions you may receive a following error message:

Building the main Guest Additions module ...fail!

Futher, investigation into a suggested log file may reveal:

/tmp/vbox.0/Makefile.include.header:97: *** Error: unable to find the sources of your current Linux kernel. Specify KERN_DIR= and run Make again.  Stop.

Read more

Introduction

The following text will describe a configuration procedure of LEMP server on Debian 9 Stretch Linux. The LEMP stack described by the below guide will consist of:

• Debian 9 Stretch Linux
• Nginx Web server
• MariaDB or MySQL relational database
• PHP 7 scripting language

Please be aware that our main objective is to configure bare bones LEMP stack on Debian 9 Stretch Linux. From this reason, no security hardening or performance fine-tuning recommendations are included in the article.

Once you have your bare bones, LEMP stack configured, consider a further hardening of your server based on the target deployment environment.

Conventions

Read more

Although Bash scripting is not a full fledged compile-able programming language, it is still very powerful and the script size can grow to enormous size. Therefore, even when you are just occasional bash scripting user or complete beginner some techniques is good to know in order to help debug you bash code. In this article we list some most command and basic bash scripting debbuging techniques.

The first debugging technique is bu using -x bash option during script execution. This will print all lines of code that is execute. For an illustration let’s consider a following example:

#!/bin/bash

echo hello

myvar=3
echo $myvar

To debug this bash shell script use -x bash option during script execution:

$ bash -x bash-script.sh 
+ echo hello
hello
+ myvar=3
+ echo 3
3

Read more

Objective

Obtaining a working LEMP stack (Linux, nginx, mariadb, php) on Debian 9 Stretch

Operating System and Software Versions

• Operating System: – Debian 9 Stretch

Requirements

Root access on a working Debian 9 Stretch installation

Difficulty

EASY

Conventions

Read more

Introduction

With the use of modern Gnu/Linux distributions package managers, package dependencies are no more a problem per-se, but usually each distribution ships with a certain version of a program, and we want to install a new version we have to compile it, or rely on third party repositories. The same thing happens if the repositories of our favorite distribution doesn’t contain a certain application we need. Also for an application distributor can be time-consuming having to provide different package formats for the same application.

Flatpak is a relatively new technology which aims at solving those kind of problems. Applications installed with Flatpack come pre-packaged with all their dependencies and run in their own sandboxed environment. In this tutorial we will see how to install and use flatpak on Fedora 28.

Read more

Below you can find a list of most frequently used commands in association with systemd targets:

List current active default target

# systemctl get-default

List all active systemd targets:

# systemctl list-units --type target

Read more

The following article will guide you through the upgrade process of Fedora 28 workstation to Fedora 29. There are multiple ways on how to perform the Fedora upgrade. This article will explain how to download fedora and upgrade to Fedora 29 via graphical user interface as well as how to use the dnf command to perform the Fedora upgrade via the Linux command line.

In this article you will learn:

• How to update the package index repository on Fedora 28 via GUI.
• How to download Fedora 29 via GUI.
• How to install Fedora 29 via GUI.
• How to upgrade Fedora via the Linux command line.

Read more

The easiest way on how to determine whether a local or remote host is a virtual machine or bare metal physical server is to use Puppet Lab’s tool facter. First we need to install facter:

Ubuntu/Debian:
# apt-get install facter
Fedora
# yum install facter

Read more