Checking version of installed AWS CLI tools on RHEL 8

Install aws cli on RHEL 8 / CentOS 8

The AWS Command Line Interface (CLI) is a all-in-one tool to manage services available on AWS cloud. On RHEL 8 / CentOS 8 the AWS CLI can be installed by using the python package management system PIP.

In this tutorial you will learn:

  • How to install AWS CLI tools on RHEL 8 / CentOS 8
  • How to configure AWS CLI tools on RHEL 8 / CentOS 8
  • How to remove AWS CLI tools on RHEL 8 / CentOS 8

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YUM on RHEL 8

How to Install YUM on RHEL 8 / CentOS 8

Fedora made the change to DNF back with Fedora 22, but CentOS and RHEL have stayed with YUM, until now. RHEL has jumped to the next gen package manager, and that’s a good thing, but if you’re missing YUM or have scripts that rely on it, you’ll still have access to the old package manager. What’s even better, you don’t need to do anything extra.

In this tutorial you will learn:

  • How to Use YUM on RHEL 8 / CentOS 8
  • What is YUM on RHEL 8 / CentOS 8, Really
  • Is there a Difference?

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Python package management system (pip) on Red Hat Enterprise Linux 8.

How to install pip in RHEL 8 / CentOS 8

Pip is a package management system used to install and manage software packages written in Python. RHEL 8 / CentOS 8 repository allows access to both pip versions for Python 2 as well as Python 3 interpreter. The pip command may be missing on your default RHEL 8 / CentOS 8 system installation.

The pip python package management tool can be easily installed by using the dnf command. Both, python 2 and 3 version can coexists on the same system and are accessible via pip2 and pip3 commands respectively.

In this tutorial you will learn:

  • How to install pip on RHEL 8 / CentOS 8 for python version 2.
  • How to install pip on RHEL 8 / CentOS 8 for python version 3.

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Use the repoquery command to list all available packages in RHEL 8 / CentOS 8

How to list installed packages on RHEL 8 / CentOS 8 Linux

There might come a time when you want to know if you have already installed a certain package on your RHEL 8 / CentOS 8. An application to be manually installed might require certain dependencies to work so you’ll have to check beforehand if these are satisfied. Or you might want to compile something and want to make sure you have all the right header libraries on your system.

In this tutorial you will learn:

  • How to use yum and dnf in RHEL 8 / CentOS 8 to list all packages
  • How to use the repoquery command to accomplish the same task
  • How to use the rpm command to list all packages installed on RHEL 8 / CentOS 8
  • How to filter the output of each command to seek certain packages
Use the repoquery command to list all available packages in RHEL 8 / CentOS 8

Use the repoquery command to list all available packages in RHEL 8 / CentOS 8

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Installed Google Chrome Browser on RHEL 8 / CentOS 8 Linux

How to install Google Chrome in RHEL 8 / CentOS 8 Linux

Google chrome browser is one of the most popular Internet browsers. It is developed by Google and can be easily installed on RHEL 8 / CentOS 8 Linux as an alternative for the Firefox browser which comes as default.

In this tutorial you will learn:

  • How to download Google Chrome browser.
  • How to install Google Chrome browser using GNU package manager and command line.
  • How to start Google Chrome Browser.

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Java on RHEL 8

How to Install Java on RHEL 8 / CentOS 8 Linux

Java is incredibly popular on servers, and if you plan on using RHEL 8 / CentOS 8, you’ll need to install it. There are a couple of ways to install Java on RHEL, both from the open source OpenJDK packages and directly from Oracle.

In this tutorial you will learn:

  • How to Install OpenJDK 8
  • How to Install OpenJDK 11
  • How to Install Oracle Java 8 JRE
  • How to Install Oracle Java 8 JDK
  • How to Switch Java Versions

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Install an RPM on RHEL 8

How to Install an RPM package on RHEL 8 / CentOS 8 Linux

There are a few different ways that you can install an RPM package on RHEL 8 / CentOS 8 as oppose to package installation from a systems repository. They each have their own merits, but DNF should probably be your first choice in most situations. It’s also good to remember that, for stability’s sake, it’s a good idea to limit your external RPM installs as much as possible.

In this tutorial you will learn:

  • How to Install an RPM with DNF
  • How to Install an RPM with Yum
  • How to Install an RPM with RPM

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How to create a simple encrypted Two-Way SSH tunnel

How to create a simple encrypted Two-Way SSH tunnel

Why would you need to create a simple Two-Way SSH tunnel? In your Linux system administration job have you ever found your self in a situation in which you cannot SSH to a any of your servers/hosts that may be behind a firewall, NAT or otherwise obstructed from an easy access.

In order to gain the access, you would need to reconfigure the firewall or create VPN which could be an enormous overhead just because you need to execute few commands from now and then. With Two-Way SSH tunnel you can connect to any destination under a single condition, which is, the ability to ssh login from the destination to the source.

If you can do that, you can as well reverse login from source to destination even if it is behind firewall or NAT.

In this tutorial you will learn:

  • How to create Two-Way SSH tunnel

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NRPE - Nagios Remote Plugin Executor

How to setup NRPE for client side monitoring

Nrpe, or Nagios Remote Plugin Executor, is the client side service of a monitoring setup. The monitoring server will send commands to the client, which listens passively when got no work to do. Upon incoming command, the nrpe checks it’s local configuration, and executes the plugin configured with the command, then sends back the results to the server for processing. You can read more about the server side installation in the Nagios installation guide, while this guide will focus on the client side.

In this tutorial you will learn:

  • How to install NRPE on Debian/Red Hat based distributions
  • How to configure NRPE to accept commands from the server
  • How to configure a custom check on the server and client side

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Bash Terminal

How to Debug Bash Scripts

There are techniques from traditional programming environments that can help.
Some basic tools like using an editor with syntax highlighting will help as well.
There are builtin options that Bash provides to make debugging and your everyday Linux System Administration job easier.

In this article you will learn some useful methods of debugging Bash scripts:

  • How to use traditonal techniques
  • How to use the xtrace option
  • How to use other Bash options
  • How to use trap

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epel-banner

How To enable the EPEL Repository on RHEL 8 / CentOS 8 Linux

Although it’s been a while since the release of Red Hat Enterprise Linux 8, the corresponding version of the EPEL repository (Extra Packages for Enterprise Linux) was only released few days ago. The repository contains packages that are not provided by the official software sources, as for example extundelete, an utility to recover deleted files from ext3/4 filesystems. Until now the solution to install those software was to build it from source or to use the previous version of EPEL (less than ideal). In this tutorial we will see how to add EPEL8 to RHEL 8 / CentOS 8.

In this tutorial you will learn:

  • How to add the EPEL8 repository to RHEL 8 / CentOS 8
  • How to check all the packages contained in the EPEL8 repository

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Install Puppet on RHEL 8 / CentOS 8

How to Install Puppet on RHEL 8 / CentOS 8

IT admins rely on Puppet to manage complex deployments every day. If your network is built on Red Hat systems, you’re going to need to install Puppet on RHEL 8 / CentOS 8. Puppet Labs provides a repository and packages, so the whole thing should be relatively hassle free.

In this tutorial you will learn:

  • How to Enable the Puppet Repo
  • How to Install Puppet for Servers/Puppet Masters
  • How to Update Servers/Puppet Masters
  • How to Install Puppet for Clients
  • How to Update Puppet Clients

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