nixCraft Linux & Unix Sysadmin/DevOps Tutorial Newsletter

[nixCraft]

Welcome to nixCraft Linux/Unix newsletter for Wednesday, 04 May 2022. I hope you will enjoy this version of the newsletter.

 

Let us start this newsletter with some bash terminal tips.

You can use the Ctrl keys to increase productivity when using bash on your macOS, Linux and Unix machines. For example, instead of typing the clear command to clear the screen, you can press the Ctrl+L to clear the screen.  These are part of the GNU readline library and default on most Linux distros as Emacs keybindings for the bash. I have attached a small cheat sheet with this newsletter for your consumption. Do try it out:

Did you know you can collect and summarize all hardware details of your machine using any one of the following commands:

sudo lshw -html > config.html # dump to the html file
xdg-open config.html # view it

Also do try out inxi command to dump hardware info on your FreeBSD or Linux machine:

inxi -Fx 

I have a detailed tutorial about finding your BIOS version under Linux, including upgrading BIOS firmware using Linux. No need to use Windows or bootable ISO anymore. Check out the following resources: 

1. 10 Linux commands to know the system
2. Linux Command To Find the System Configuration And Hardware Information

Other tutorials from nixCraft:

• How to install and edit desktop files on Linux (Desktop entries)
  Linux comes with three commands for developers, sysadmins and users to set up a hierarchy of applications, typically displayed as a menu. In other words, these commands allow third-party software to add menu items that work for all desktops. In addition, it allows Linux system administrators to edit menus in a way that affects all desktops using the following commands to install and edit desktop files on Linux to make Desktop entries
   
• Update CentOS 8 Linux
  As you know, Red Hat ended the security and update status for CentOS 8 Linux on 31/Dec/2021. As a result, you need to switch to either CentOS Stream, or if you need 100% RHEL compatibility, read the following guide about migrating CentOS 8 to various distros:
  • How to migrate from CentOS 8 to Rocky Linux (conversion)
  • How to migrate from CentOS 8 to AlmaLinux (conversion)
  • How to migrate from CentOS 8 to CentOS stream conversion
     
• How to upgrade from Ubuntu 20.04 LTS to 22.04 LTS
  Ubuntu 22.04 LTS (“Jammy Jellyfish”) is released now. This tutorial explains how to safely upgrade from Ubuntu 20.04 LTS (Focal Fossa) to Ubuntu 22.04 LTS using the command-line and GUI options.
   
• How much does a Linux desktop OS cost?
  Let us say you want to support Linux and buy an actual Linux desktop OS like you buy Windows desktop operating system from the market. How much would it cost price-wise, and what would you get in return when you buy a yearly subscription?
   
• How to use htmlq to extract content from HTML files on Linux, macOS or FreeBSD
  Most of us use love and use the jq command. It works on Linux or Unix-like systems to extract data from JSON documents. Recently I found htmlq, which is like jq and written in Rust lang. Imagine being able to sed or grep for HTML data. We can search, slice, and filter HTML data with htmlq. Let us see how to install and use this handy tool on Linux or Unix and play with HTML data.
   
• How to install GIMP 2.10 on Ubuntu or Debian Linux
  This quick tutorial explains how to download and install the latest GIMP application on Ubuntu or Debian Linux and friend using the CLI.
   
• Debian 11 Set Up OpenVPN Server In 5 Minutes
  I am a new Debian Linux 11 server user. How do I set up an OpenVPN Server on Debian Linux version 11 server to shield my browsing activity from bad guys on public Wi-Fi, and more?
   
• How to install aws cli on Linux
  The AWS CLI is an essential tool for developers and sysadmin to automate and interact with AWS cloud services. It is an open-source tool built on the AWS SDL for Python. As a result, you no longer need to use AWS Management Console. Instead, you can use Linux terminal and commands for managing AWS resources. Let us see how to install AWS CLI on Linux using the command-line options.
   
• How to install Chromium browser on Ubuntu Linux
  Chromium is a free and open-source web browser project designed and maintained by Google. Google Chrome browser uses Chromium codebase and other proprietary components for additional features required to play games, music and movies protected by DRM. This page explains how to install Chromium browser on Ubuntu Linux 20.04 and 22.04 LTS desktop computers.
   
• How to find out if Raspberry PI Linux OS needs a reboot
  When you use the apt command to update the Raspberry Pi OS, no notification indicates whether you need to reboot the Raspberry Pi 3 or 4 for Linux kernel updates. So say you have a lab of 4 RPi4 and managing updates using ansible, then you need an automated way to find out if a reboot is required to load a new Linux kernel on your Raspberry Pi OS.
   
• How to trim leading and trailing white space in bash
  So I have this specific use case where I get data in a comma-separated values (CSV) file. I pick up the company name, address, telephone, email, and some other data from that file. Once data is collected, I create a final pdf using a simple script. Unfortunately, data comes with unwanted leading and trailing white spaces in each field. So my final pdf file gets messed up because of those white space. Let us see how to trim leading and trailing white space for a string in Bash running on Linux or Unix machines.
   
• How to on enable kernel crash dump on Debian Linux
  How do I enable kernel crash dump Debian Linux 9/10/11 using the command-line option? How can I view crash reports on Debian machine?
   
• How To Convert AWS Route53 to Cloudflare Let’s Encrypt DNS challenge with acme.sh
  I already wrote about setting up wildcard Let’s Encrypt SSL/TLS with AWS Route53 DNS for Nginx or Apache. One of my clients decided to use Cloudflare CDN and DNS at some point. They changed their DNS to Cloudflare. Naturally, their wildcard certificate failed because it was using Route53 DNS authentication to issue the certificate. Let us see how to convert existing or expired TLS/SSL certification renewal from AWS Route53 to Cloudflare.
   
• How to install YubiKey Manager GUI on Linux
  One can use a hardware security key such as YubiKey for OTP or FIDO2 for additional security on Linux to protect disks, ssh keys, password manager, web applications and more. Since I am a full-time Linux desktop user, I thought today I would document how to install the YubiKey GUI Manager to configure functionality on your YubiKey on a Linux desktop.
   
• How to install whois on Ubuntu / Debian Linux
  While working on the client’s system, I found that the whois client was missing. So I used that in one of my deployment scripts. I should add that to cloud-init or Ansible, but the Ubuntu server was already running.
   
• How to install and upgrade OpenSSH server on FreeBSD
  Another day I wrote about setting up ssh public key password-less authentication for FreeBSD server version 12/13 with an optional 2FA hardware USB key (FIDO 2) for additional protection. However, FIDO2 and key type ecdsa-sk and ed25519-sk are not supported by the OpenSSH client and server version shipped with FreeBSD 12 or 13. But, fear not, we can safely upgrade the OpenSSH version using ports collection. This page explains how to install and configure the latest portable version of the OpenSSH client and server on FreeBSD 13.
   
• How to set up ssh public key password-less on FreeBSD
  SSH is an essential tool for login into the FreeBSD Unix box. Without SSH, you cannot manage a remote server easily. Furthermore, SSH means secure shell, and it is a replacement for insecure protocols such as telnet. This page explains how to configure and set up ssh key-based password-less authentication on a FreeBSD server or workstation.