nixCraft Linux & Unix Sysadmin/DevOps Tutorial Newsletter

[nixCraft]

Welcome to nixCraft Linux/Unix newsletter for Wednesday, 15 April 2020. I hope you will enjoy this version of the newsletter.

Dear readers,
Millions of livelihoods have been shattered and there is growing uncertainty due to Covid19. I have not sent a newsletter since Jan-2020. I am resuming it, and this one covers all topics/tutorials posted since Jan/2020. Stay safe indoors.

• Linux / Unix desktop fun: gti get jeep/car when you mistype git
  One of the most common mistakes developers and ops people make is typing gti instead of git command. I set an alias i.e. alias gti=git, but then you may miss out on the jeep/car on your screen.
   
• System76 Announces AMD Threadripper Linux Workstations
  System76 is a Denver, Colorado-based American computer manufacturer. They are specializing in the sale of Linux powered laptops, desktops, and servers. Last year System76 announced two Intel laptops with Coreboot, which as an alternative to proprietary BIOS using Intel 10th Gen CPUs. Now, System76 updated its Linux workstations line and ship with the latest AMD chips for CPU-intensive workloads. But how much of a difference can 64 cores AMD CPU make?
   
• Letsencrypt is revoking certificates on March 4
  Let’s Encrypt is a non-profit certificate authority that provides X.509 certificates for Transport Layer Security (TLS) encryption free of cost. The TLS certificate is valid for 90 days only. However, Due to the bug, they need to revoke many (read as “certain”) Let’s Encrypt TLS/SSL certificates. Let us see how to find out if you are affected by this bug and how you can fix it to avoid any problems with your TLS/SSL certificates.
   
• Linux uninstall package / software using the CLI
  How do I uninstall package or software using the command line in Linux operating systems? How can I uninstall software on a Debian or Ubuntu Linux? Can you tell me command to uninstall package on a CentOS/RHEL/Oracle/Fedora Linux?
   
• Unix Basics Quiz {trending}
  Let us test your basic knowledge of Unix systems, including commands.
   
• Ansible zypper update all packages on OpenSUSE/SUSE
  I got a cluster of servers powered by OpenSUSE / SUSE Enterprise Linux. How can I update all of them using the zypper module of Ansible? How can I use Ansible for system updates and reboot the server when kernel upgrades took place on SUSE/OpenSUSE?
   
• CentOS 8 set up WireGuard VPN server {trending}
  How do I install and set up WireGuard VPN server on a CentOS 8 Linux? How can I configure CentOS 8 as the WireGuard VPN server?
   
• CentOS 8 Set Up OpenVPN Server In 5 Minutes {trending}
  How do I set up an OpenVPN Server on CentOS 8 Linux server to shield my browsing activity from bad guys on public Wi-Fi, and more?
   
• Linux Quiz {trending}
  Let us test your basic knowledge of Linux systems, including commands.
   
• How to enable firewalld logging for denied packets on Linux
  How do I enable firewalld logging for denied packets on Linux operating systems so that I can view all dropped packets information? How can I view a log of the traffic blocked by FirewallD under a CentOS/RHEL (Red Hat Enterprise Linux)/Suse/OpenSUSE Linux?
   
• How to Set Up and Use LXD on CentOS 8.x / RHEL 8.x {trending}
  LXD is a next generation system container manager. It offers a user experience similar to virtual machines but using Linux containers instead. It’s image based with pre-made images available for a wide number of Linux distributions. How do I set up and install LXD on a CentOS 8.x or RHEL 8.x server?
   
• Vim show line numbers by default on Linux
  How do I show line numbers in Vim by default on Linux?
   
• Linux bind IP that doesn’t exist with net.ipv4.ip_nonlocal_bind {trending}
  How do I allow Linux processes to bind to IP address that doesn’t exist yet on my Linux systems or server?
   
• Change my default shell in Linux using chsh
  How do I change my default shell in Linux?
   
• Linux iptables delete prerouting rule command
  I am a new Linux server sysadmin. I need to delete the PREROUTING rule. How do I delete the prerouting rule on Linux server?
   
• How to Install phpredis on CentOS 8 / RHEL 8
  How do I install PHP extension called phpredis (php-redis) for interfacing with Redis cluster on CentOS 8 or RHEL 8?
   
• How to Undo in Vim / Vi text editor {trending}
  How do I undo a recent change in the vim text editor?
   
• Ubuntu Install Tinc and Set Up a Basic VPN {trending}
  How do I install Tinc and Set Up a Basic VPN on Ubuntu Linux 18.04/20.04 LTS server?
   
• Ansible apt update all packages on Ubuntu / Debian Linux {trending}
  I have a bunch of servers powered by Ubuntu and Debian Linux. How do I update all of them using the apt module of Ansible? How can I use Ansible for system updates and reboot the box when kernel upgrades took place?
   
• Linux extend file system after resize disk volume
  I increased the size of the volume in Linux using my cloud service providers’ online tool. My original disk size was 200GB, and I grew to 400GB. However, I only able to use 200GB and not 400GB. How do I resizing my disk and extend the file system resizing a disk volume?
   
• Thinkpad update firmware on Linux (X1 extreme/P1 gen2) {trending}
  I have ThinkPad P1 Gen 2 or X1 Extreme 2nd Laptop. Can I easily Install ThinkPad firmware updates on Linux using GUI?
   
• OpenSUSE install sudo to execute commands as root
  There is no sudo installed by default on my OpenSUSE Linux server. Other users and I need to use ‘su -‘ command to run commands as root. How do I install a sudo package on OpenSUSE Linux?
   
• Explain DEBIAN_FRONTEND apt-get variable for Ubuntu / Debian {trending}
  Can you explain DEBIAN_FRONTEND apt or apt-get variable? How and why I need to use this in Docker or shell scripts under a Debian and Ubuntu Linux?
   
• Linux / Unix Desktop Fun: Text Mode ASCII-art Box and Comment Drawing {trending}
  Boxes command is a text filter and a little known tool that can draw any kind of ASCII art box around its input text or code for fun and profit. You can quickly create email signatures, or create regional comments in any programming language. This command was intended to be used with the vim text editor, but can be used with any text editor which supports filters, as well as from the command line as a standalone tool.
   
• Ubuntu add-apt-repository command not found error and solution
  I am trying to run a command named ‘sudo add-apt-repository ppa:foo/bar‘ but getting the following error on screen: sudo: add-apt-repository: command not found. How do I fix this problem on Ubuntu Linux 14.04 or 16.04 or 18.04 or 20.4 LTS and Debian Linux server?
   
• Linux and Unix dig Command Examples {trending}
  I am a new Linux/Unix command line user. How do I use dig command line utility to query DNS (Domain Name System) servers on Linux and Unix-like operating systems? How do I use dig command to find the IP address of a host name or host Name of an IP address?
   
• Make Linux/Unix Script Portable With #!/usr/bin/env As a Shebang {trending}
  If you want to make sure that script is portable across different UNIX like operating systems you need to use /usr/bin/env command as shebang.
   
• exa a modern replacement for ls command in rust for Linux/Unix {trending}
  ls is a command to show files in Linux and Unix-like operating systems. A ls command first appeared in a version of AT&T UNIX as well as in Multics. BSD and GNU Coreutils package provides the ls command with minor syntax changes. There is now third alternative named exa. It is a modern replacement for ls command.
   
• 20 Unix/Linux Command Line Tricks – Part I {trending}
  Let us start new year with these Unix and Linux command line tricks to increase productivity at the Terminal. I have found them over the years, and I am now going to share with you.
   
• Linux append text to end of file
  I am new Linux user and sysadmin for CentOS enterprise Linux 7 running on couple of VMs and bare metal boxes. How to add lines to end of file? How do I append text to end of file using the cli on Linux? What command I need to type to send the output of the command to end of file?
   
• How to append text to a file when using sudo command on Linux or Unix
  As we learned that there are multiple ways to append text to a file using the sudo command.
   
• Append Current Date To Filename in Bash Shell
  How do I append current date (mm_dd_yyyy format) to a filename (e.g., backup_mm_dd_yyyy.sql) under Linux and UNIX like operating systems? How can I append a current date from a variable to a filename under Linux or Unix bash shell? How do I append date to filename?
   
• How to update/upgrade Pi-hole with an OpenVPN on Ubuntu/Debian Linux server
  I installed an OpenVPN server with Pi-hole software to block block ads, reduced my 4G/3G/LTE traffic on the same Debian or Ubuntu Linux server. How do I upgrade my Pi-hole to the latest version using command line?

Until next time.