LAMP stack server installation on RHEL 8 / CentOS 8

How to install LAMP Server on RHEL 8 / CentOS 8 Linux

The LAMP server is the foundation of Linux web hosting. If you’re looking to set up a LAMP stack to host your website, this guide will provide you with the necessary information on how to get start with LAMP on RHEL 8 / CentOS 8 Linux server.

In this tutorial you will learn:

  • How to install all LAMP prerequisite packages on RHEL 8 / CentOS 8.
  • How to secure MariaDB database.
  • How to start httpd and MariaDB services.
  • How to open HTTP and HTTPS firewall ports.

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Enabled IPv6 on RHEL 8 Linux system.

RHEL 8 / CentOS 8 enable/disable IPv6

An Internet Protocol Version 6 (IPv6) address is an identifier of a network interface of a computer or a network node involved in an IPv6 computer network. This article will guide the user via simple steps on how to disable or re-enable IPv6 network addresses on RHEL 8 / CentOS 8. To temporarily enable/disable the IPv6 address on RHEL 8 / CentOS 8 we will use the sysctl command. Additionally, to permanently disable the IPv6 address we will modify the GRUB boot options.

In this tutorial you will learn:

  • How to temporarily disable the IPv6 address.
  • How to permanently disable IPv6 by modifying the GRUB boot options.

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Active SSH service and firewall SSH port 22 open on RHEL 8

RHEL 8 / CentOS 8 enable ssh service

The following article will explain how to install and start SSH service on RHEL 8 / CentOS 8 system. SSH is a client-server service providing secure encrypted connections over the network connection.

In this tutorial you will learn:

  • How to Install SSH service.
  • How to start SSH service.
  • How to enable SSH to start after reboot.
  • How to open SSH port 22 for incoming traffic.

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How to check Linux version

How to check Linux Version

The common scenario is that you have been given an access to a Linux system physically or via remote login and you have no idea what Linux version is installed on this particular system. Given that many of the today’s Linux Distributions have implemented systemd as part of their core design, to check for a Linux version is in many cases relatively simple procedure.

The simplest way to check Linux version is by using the hostnamectl command without any arguments. For example the below hostnamectl command will return the Linux distribution name, version and codename in use along with the currently loaded Linux kernel version:

$ hostnamectl 
   Static hostname: x220
         Icon name: computer-laptop
           Chassis: laptop
        Machine ID: 2d4efda5efb0430faeb2087d0a335c6b
           Boot ID: f8c4a3a776a74d42878347efc2c00634
  Operating System: Debian GNU/Linux 10 (buster)
            Kernel: Linux 4.9.0-9-amd64
      Architecture: x86-64
DID YOU KNOW?

It is a common mistake to refer to the entire GNU/Linux operating system simply as Linux. The important note here is that the so called Linux is actually only the Kernel part of the system whereas GNU is the actual system as in collection of pre-compiled binaries, libraries and system tools. Both GNU and Linux kernel must function in tandem in order for the operating system to actually work.

Hence, one cannot exists without the other, so next time when you talk about your operating system and you wish to be technically correct, refer to it as GNU/Linux or simply as Lignux.

In this tutorial you will learn:

  • Basic introduction to Linux package
  • How to check system architecture and Linux kernel version
  • How to check CPU architecture
  • How to check CentOS, Redhat, Debian, Ubuntu, Mint, Arch, Fedora Linux system version

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Ansible Architecture

How to install and configure Ansible on Redhat Enterprise Linux 8

This tutorial covers step by step installation and configuration of Ansible on Redhat Enterprise Linux 8.
Ansible is the leading Open Source configuration management system. It makes it easy for administrators and operations teams to control thousands of servers from central machine without installing agents on them.

In this tutorial you will learn:

  • Ansible Overview
  • Install and Configure Python
  • Set Password-less SSH
  • Install Ansible
  • Testing and Managing the Ansible

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Disabling proxy for internal repository

How to add repositories to Red Hat Linux with and without a proxy

Objective

Our objective is to set up access to internal and remote yum repositories while some of them are behind proxy servers.

Operating System and Software Versions

  • Operating system: Red Hat Enterprise Linux 7.5

Requirements

Privileged access to the system

Difficulty

EASY

Conventions

  • # – requires given linux commands to be executed with root privileges either directly as a root user or by use of sudo command
  • $ – given linux commands to be executed as a regular non-privileged user

Introduction

In a corporate environment it is common to limit Internet access – both for security and accountability. This is often accomplished by using proxy servers that enable access to the Internet after some sort of authentication, while inspect and log all traffic passing trough them. This way the company can, for example find the employee who downloaded the virus that wreak havoc within the corporate system (or at least the employee who’s credentials where stolen to do so), or filter the traffic, preventing access to well-known harmful sites to protect employee equipment.

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Tomcat providing the examples application

How to set up Apache webserver proxy in front of Apache Tomcat on Red Hat Linux

Objective

Our objective is to setup Apache httpd to work as a proxy in front of the Apache Tomcat application container.

Operating System and Software Versions

  • Operating system: Red Hat Enterprise Linux 7.5
  • Software: Apache httpd, Apache Tomcat

Requirements

Privileged access to the system

Difficulty

EASY

Conventions

  • # – requires given linux commands to be executed with root privileges either directly as a root user or by use of sudo command
  • $ – given linux commands to be executed as a regular non-privileged user

Introduction

Using Apache httpd as a proxy to an Apache Tomcat application container is a common setup. It comes with many use cases, the most trivial is serving static content from httpd, while providing services implementing heavy business logic from an application written in Java that resides in the Tomcat container.

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Summary of interactive yum update

Preparing for applying updates on Red Hat Linux

Objective

Our objective is to ensure that updating the operating system will run smoothly and without errors.

Operating System and Software Versions

  • Operating system: Red Hat Enterprise Linux 6+

Requirements

Privileged access to the systems

Difficulty

EASY

Conventions

  • # – requires given linux commands to be executed with root privileges either directly as a root user or by use of sudo command
  • $ – given linux commands to be executed as a regular non-privileged user

Introduction

Keeping the system up to date is an every day task for a sysadmin, as well as a desktop user. By applying the latest (stable) available software on the system we can take advantage of the latest features, and will be more protected from security issues and hopefully suffer less from bugs. To update the system you will need configured yum repositories that act as the source of the updated software.

If you sit next to the machine that is running the operating system to be updated, you can easily act if something goes wrong during update, like checking the output on the terminal, or boot to a live system if the upgraded one does not return from reboot – but this is not always the case. Think of a datacenter with hundreds or thousands of (virtual) machines, or simply a physical PC that you have to upgrade remotely.

There are simple steps we can perform to prepare the system for upgrade, and possibly clear any problem that would endanger a successful update.

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Installing custom scripts with rpm

Unifying custom scripts system-wide with rpm on Red Hat/CentOS

Objective

Our goal is to build rpm packages with custom content, unifying scripts across any number of systems, including versioning, deployment and undeployment.

Operating System and Software Versions

  • Operating system: Red Hat Enterprise Linux 7.5
  • Software: rpm-build 4.11.3+

Requirements

Privileged access to the system for install, normal access for build.

Difficulty

MEDIUM

Conventions

  • # – requires given linux commands to be executed with root privileges either directly as a root user or by use of sudo command
  • $ – given linux commands to be executed as a regular non-privileged user

Introduction

One of the core feature of any Linux system is that they are built for automation. If a task may need to be executed more than one time – even with some part of it changing on next run – a sysadmin is provided with countless tools to automate it, from simple shell scripts run by hand on demand (thus eliminating typo errors, or only save some keyboard hits) to complex scripted systems where tasks run from cron at a specified time, interacting with each other, working with the result of another script, maybe controlled by a central management system etc.

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FreeIPA login page

How to install and configure FreeIPA on Red Hat Linux

Objective

Our objective is to install and configure a standalone FreeIPA server on Red Hat Enterprise Linux.

Operating System and Software Versions

  • Operating System: Red Hat Enterprise Linux 7.5
  • Software: FreeIPA 4.5.4-10

Requirements

Privileged access to the target server, available software repository.

Difficulty

MEDIUM

Conventions

  • # – requires given linux commands to be executed with root privileges either directly as a root user or by use of sudo command
  • $ – given linux commands to be executed as a regular non-privileged user

Introduction

FreeIPA is mainly a directory service, where you can store information about your users, and their rights regarding login, become root, or just run a specific command as root on your systems that are joined your FreeIPA domain, and many more. Although this is the main feature of the service, there are optional components that can be very useful, like DNS and PKI – this makes FreeIPA an essential infrastructural part of a Linux-based system. It has a nice web-based GUI, and powerful command line interface.

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Solving dependencies with rpm

Working with package dependencies on Red Hat Linux

Objective

Our goal is to get used to the tools available to find out information about package dependencies on an RPM based system.

Operating System and Software Versions

  • Operating system: Red Hat Enterprise Linux 7.5
  • Software: rpm 4.11, yum 3.4.3

Requirements

Privileged access to the system.

Difficulty

EASY

Conventions

  • # – requires given linux commands to be executed with root privileges either directly as a root user or by use of sudo command
  • $ – given linux commands to be executed as a regular non-privileged user

Introduction

RPM, which stands for Red Hat Package Manager, is a well-known and mature package manager used by all Red Hat flavor distributions, as well as SuSE. With RPM the packager can define relations between packages, and even with versions of packages – for example, an Apache Tomcat server needs proper Java environment present to be able to run.

On the other hand, to install a Java environment, you don’t need a Tomcat server – you may decide to run some different Java based application, maybe one written by yourself started by hand when needed to do it’s job. In other words, the Tomcat server depends on Java.

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