Mastering Linux System Administration. Richard Blum

      1 Log onto your CentOS server as the root user account.

      2 From the command‐line prompt, enter the command dnf install flatpak. There are lots of dependencies required, so you'll see quite a few packages install.

      3 Once flatpak is installed, you will need to point it to a flatpak container repository. The most popular one is Flathub. Configure that by entering the command flatpak remote‐add ‐‐if‐not‐exists flathub https://flathub.org/repo/flathub.flatpakrepo. You should see output that's similar to this:# flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo Note that the directories '/var/lib/flatpak/exports/share' '/root/.local/share/flatpak/exports/share' are not in the search path set by the XDG_DATA_DIRS environment variable, so applications installed by Flatpak may not appear on your desktop until the session is restarted. #

      4 Test the flatpak command by entering the command flatpak list.# flatpak list #Not too exciting. When you first install flatpak, there won't be any containers installed, but now you know that flatpak is installed.

       Recognize Red Hat packages. Developers bundle the files required for an application into a package to make it easier to install. A package management system allows you to easily track what software packages are installed on your Linux system, as well as install, update, and remove them. Red Hat–based Linux distributions use the Red Hat Package Management (RPM) system for managing application software. The rpm command‐line tool provides access to the package management database, allowing you to quickly determine the status of installed packages.Master It The curl software package allows you to easily transfer data using a multitude of protocols (such as FTP, HTTP, and SCP) from the command line. What command would you use to determine whether curl is installed on your Linux system? If the package is installed, what command would you use to view the version and a description of the package?

       Use automated Red Hat package managers. Most Red Hat–based Linux distributions are based on the rpm utility but use different front‐end tools at the command line. Red Hat, CentOS, and Fedora use dnf for installing and managing software packages. The dnf tool automatically installs any software packages required by the package you install.Master It The perf utility allows you to monitor the performance of a Linux system. What command would you use to check whether the perf software is available as an rpm package for your Linux system, and what command would you use to install it? What command would you use to remove it?

       Manually install Red Hat packages. Not all Linux systems are connected to the Internet, allowing the automated package management tools to connect to a repository. In those situations, you'll need to manually find and download RPM software packages and then use the rpm command to manually install the package. The most common options used to install software are the ‐Uvh options, which will update the package if it's already installed and provide verbose information on the installation progress.Master It What steps would you need to take to install the perf utility if your Linux system is not connected to the Internet?

        Install flatpak application containers. Application containers are relatively new in software package management. Containers bundle all of the software required for an application to run, including all files the application is dependent on. This makes containers portable and easily moved between systems. Red Hat Linux–based distributions use the flatpak container format.Master It Cointop is a terminal‐based application for tracking cryptocurrencies. What command would you use to check if there's a flatpak container for it, and what command would you use to install it?