Identifying the CentOS Release version

How to check CentOS version

There are several ways on how to check what version of CentOS is running on your system. The simplest way to check for the CentOS version number is to execute the cat /etc/centos-release command. Identifying the accurate CentOS version may be required to help you or your support team to troubleshoot your CentOS system.

Read more

main-image

How to query packages information with the rpm package manager

RPM is the recursive acronym for RPM Package Manager: it is the default low level package manager in some of the most famous and most used Linux distributions, such as Fedora, Red Hat Enterprise Linux, CentOS, OpenSUSE and their derivatives. The software, as you can expect, is free and open source; when invoked with the -q option it can be used to query packages to retrieve specific information, such as dependencies, recommendations, files etc. In this tutorial we learn how to perform such queries.

In this tutorial you will learn:

  • How to run rpm in “query” mode
  • How to obtain general information about a package
  • How to read a package changelog
  • How to list the files provided by a package
  • How to list the scripts used by a package
  • How to list a package dependencies and recommendations
  • How to list packages rendered obsolete by an rpm
main-image

How to query packages information with the rpm package manager

Read more

How to work with dnf package groups

How to work with dnf package groups

Dnf is the default high-level package manager in the Red Hat family of distributions, which includes Fedora, Red Hat Enterprise Linux and all its clones. It is the successor of Yum, and indeed using the yum command in recent versions of the distributions mentioned above, is just another way to call dnf. Dnf has a lot of nice features
and plugins which help us install, update and remove software packaged in the “.rpm” format. In this tutorial we explore dnf package groups and learn how to handle them.

In this tutorial you will learn:

  • What is a package group
  • How to get information about a package group
  • How to list all available package groups
  • How to install, upgrade and remove a package group
How to work with dnf package groups

How to work with dnf package groups

Read more

The chrony NTP server source list on AlmaLinux

How to configure NTP server and client on AlmaLinux

NTP stands for Network Time Protocol and is used for clock synchronization across multiple computers. An NTP server is responsible for keeping a set of computers in sync with each other. On a local network, the server should be able to keep all client systems to within a single millisecond of each other.

Such a configuration would be necessary if, for example, the systems needed to start or stop a task in unison at a precise time. In this article, we’ll show you how to configure an NTP server on AlmaLinux and how to configure a client system to sync its system time with said server. This can be done from a fresh AlmaLinux installation or on a system that has migrated from CentOS to AlmaLinux.

In this tutorial you will learn:

  • How to install and configure chrony NTP server
  • How to open firewall to incoming NTP requests
  • How to connect to an NTP server from a client machine
The chrony NTP server source list on AlmaLinux

The chrony NTP server source list on AlmaLinux

Read more

Setting up a MySQL database and user on AlmaLinux

How to install MySQL on AlmaLinux

In this guide, we will show you how to install MySQL on AlmaLinux. There are two separate packages for this on AlmaLinux, depending on what you need to do. You can either install the MySQL client package, which is used to connect to MySQL servers, or install the MySQL server software, which can be used to host your own databases. We’ll cover both below.

After installing a MySQL server, we’ll also go over the first steps you’ll need to get started with hosting a database, which includes making a username and password, creating a database, and granting user permissions on that database. AlmaLinux is a good Linux distro for hosting MySQL, whether you’ve freshly installed AlmaLinux or migrated from CentOS to AlmaLinux.

In this tutorial you will learn:

  • Install MySQL Client on AlmaLinux
  • Install MySQL Server on AlmaLinux
  • How to setup a MySQL database
Setting up a MySQL database and user on AlmaLinux

Setting up a MySQL database and user on AlmaLinux

Read more

Installing Git on AlmaLinux

How to install Git on AlmaLinux

Git is a versioning control system, mainly used by programmers to issue changes to applications and keep track of the revisions. However, it’s also commonly used by everyday users, since they’re able to browse and download the source code and binaries of millions of applications from websites like GitHub and GitLab.

On Linux, familiarity with Git and access to the command line utility is borderline essential. That is, if you’re the type of user who likes to install programs to unlock additional features and the like.

In this guide, we’ll show you the step by step instructions to install Git on AlmaLinux. Once it’s installed, you can read our other guide on how to get started using Git. This is a great process to do right after installing AlmaLinux or migrating from CentOS to AlmaLinux.

In this tutorial you will learn:

  • How to install Git on AlmaLinux
Installing Git on AlmaLinux

Installing Git on AlmaLinux

Read more

Installing Apache on AlmaLinux

How to install Apache on AlmaLinux

Apache is one of the most popular and longstanding HTTP servers. It’s an open-source and cross-platform web server software developed and maintained by Apache Software Foundation. It’s easy to set up and learn to use, which has led to its widespread adoption for small and large scale websites.

In this guide, we’ll go over the step by step instructions to install Apache on AlmaLinux. Feel free to follow along with us, whether you have a fresh AlmaLinux installation or have migrated from CentOS to AlmaLinux.

In this tutorial you will learn:

  • How to install Apache web server on AlmaLinux
  • How to control Apache web server with systemctl commands
  • How to open firewall for HTTP (port 80) and HTTPS (port 443)
  • How to host a website with Apache
  • How to install SSL certificate with Let’s Encrypt
Installing Apache on AlmaLinux

Installing Apache on AlmaLinux

Read more

Adding a new user account on AlmaLinux

How to add user on AlmaLinux

After installing AlmaLinux or migrating from CentOS to AlmaLinux, most users will eventually run into the need to do some user account management. This is especially true if you only have a root account on your system and need to setup one or more normal users.

In this guide, we’ll show you the step by step instructions to add a new user on an AlmaLinux system. This can be done through both GUI and command line. We’ll be covering both methods in this guide, so you can pick whichever option is most convenient for you.

In this tutorial you will learn:

  • How to add a new user on AlmaLinux from command line
  • How to add a new user on AlmaLinux from GNOME GUI
Adding a new user account on AlmaLinux

Adding a new user account on AlmaLinux

Read more

CentOS Linux

CentOS vs CentOS Stream

Up until a late 2020 announcement from Red Hat, CentOS Linux had a longstanding reputation as a dependable and enterprise-class Linux distribution. And now, the main purpose of CentOS is shifting. Along with that comes a name change to CentOS Stream.

In this article, we’ll talk about this change of direction for CentOS, and what it means for the huge community of users and businesses that have relied on the distro for years. We’ll also see what’s next, as many users are left scrambling for a replacement so they can avoid switching to CentOS Stream.

Read more

Docker running a container image on AlmaLinux

Install Docker on AlmaLinux

Docker is a tool that is used to run software in a container. It’s a great way for developers and users to worry less about compatibility with an operating system and dependencies because the contained software should run identically on any system.

If you’ve recently installed AlmaLinux or migrated from CentOS to AlmaLinux, you may be wondering how to get Docker up and running on the system. Unfortunately, Red Hat Enterprise Linux doesn’t offer native support for Docker, and neither does AlmaLinux, since it is a fork of RHEL. Instead, Red Hat pushes support for Podman, an alternative to Docker. This makes Docker a bit harder to install, but it’s still possible on AlmaLinux.

In this guide, we’ll show you how to install Docker on AlmaLinux and get started with installing containerized software. After Docker is installed, you can use it to install software packages much the same way you would use your distro’s package manager to download an app. The difference of using Docker is that everything is more automated, with compatibility and dependencies no longer being potential issues.

In this tutorial you will learn:

  • How to install Docker
  • How to run Docker without root
  • How to search for a Docker image
  • How to install a Docker image
  • How to run a Docker image
  • How to monitor Docker with various commands
Docker running a container image on AlmaLinux

Docker running a container image on AlmaLinux

Read more

Changing the time zone via command line and GUI on AlmaLinux

How to set/change time zone on AlmaLinux

The objective of this guide is to show how to set the system time zone on AlmaLinux. This can be done from both GUI and command line, so we’ll be covering both methods in the following instructions.

Setting your system time and time zone is usually done when initially installing AlmaLinux or migrating from CentOS to AlmaLinux. If you skipped that step during installation, have switched time zones, or your system clock has drifted out of sync, we’ll help you get it fixed.

In this tutorial you will learn:

  • How to set time zone on AlmaLinux from GNOME GUI
  • How to set time zone on AlmaLinux from command line
Changing the time zone via command line and GUI on AlmaLinux

Changing the time zone via command line and GUI on AlmaLinux

Read more

How to disable or enable the firewall on AlmaLinux

How to disable/enable firewall on AlmaLinux

firewalld is the firewall manager that comes pre-installed on AlmaLinux, whether you’ve freshly installed AlmaLinux or migrated from CentOS to AlmaLinux. By default, the firewall is turned on, meaning that a very limited number of services are able to receive incoming traffic.

This is a nice security feature, but it means that the user must be knowledgeable enough to configure the firewall whenever they install a new service on the system, like HTTPD or SSH for example. Otherwise, connections from the internet can’t reach these services.

In this guide, we’ll see how to disable or enable the firewall in AlmaLinux, along with checking the status of the firewall. These are good troubleshooting options when trying to determine if a firewall rule is blocking traffic to or from a particular service.

DID YOU KNOW?
firewalld is simply a front end for the system’s nftables (formerly iptables) firewall. This makes the firewall easier to interact with, but essentially firewalld just translates all our commands into corresponding nft commands.

In this tutorial you will learn:

  • How to check the firewall status on AlmaLinux
  • How to stop firewall on AlmaLinux
  • How to start firewall on AlmaLinux
  • How to permanently disable firewall on AlmaLinux
  • How to enable firewall to start after reboot
How to disable or enable the firewall on AlmaLinux

How to disable or enable the firewall on AlmaLinux

Read more