today's howtos
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How to Install Calibre E-book Server on Ubuntu 22.04
Calibre is a free and open-source e-book manager. In this tutorial, you will learn to install the Calibre server on an Ubuntu 22.04 machine.
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Install Sysdig System Visibility Tool on Ubuntu 22.04 - kifarunix.com
This tutorial will take you through how to install Sysdig system visibility tool on Ubuntu 22.04. Sysdig is a simple visibility tool that provides deep visibility into your system.
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A brief history of looking up host addresses in Unix
In the beginning, back in V7 Unix and earlier, Unix didn't have networking and so the standard C library didn't have anything to look up host addresses. When BSD famously added IP networking to BSD Unix, that had to change, so BSD added C library functions to look up this sort of information, in the form of the gethost* functions, which first appeared in 4.1c BSD but are probably most widely known in the 4.2 BSD version. Because this was before DNS was really a thing, functions like gethostbyname() searched through /etc/hosts.
The next step in practice in host lookups was done by Sun, when they introduced what was then called YP (until it had to be renamed to NIS because of trademark issues). To avoid having to distribute a potentially large /etc/hosts to all machines and to speed up lookups in it, Sun made their gethostbyaddr() be able to look up host entries through YP; on the YP server, your hosts file was compiled into a database file for efficient lookups (along with all of the other YP information sources). As a fallback, gethostbyaddr could still use your local /etc/hosts, which was useful to insure that you weren't completely out to sea if the YP server stopped responding to you. People who didn't use YP (which was a lot of us) still used /etc/hosts, and perhaps distributed a (large) local version to all of their machines.
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I wish that systemd (and everything) would rate-limit configuration warnings
The obvious reason you're seeing this message is that the 22.04 'oidentd@.service' template service unit specifies the now-obsolete 'StandardError=syslog' setting. You're seeing this message frequently because systemd apparently generates these messages whenever the unit is started and oidentd.socket is set to start it on every connection (ie, oidentd.socket specifies 'Accept=yes', which is also the only time you can have a templated socket service unit).
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Using Prometheus's recent '@ end()' PromQL feature to reduce graph noise
Modern versions of Prometheus support a special '@' time modifier on PromQL queries. These let you evaluate a part of the query at a specific, fixed time, rather than at either the 'now' of an instant query or at every step of a range query. In addition to literal times, this can use two special time functions, 'start()' and 'end()', which evaluate to the start and end of a range query.
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Vim settings I'm using for editing YAML (with a sideline into Python)
I normally stick with minimal Vim customizations, partly because as a system administrator I'm not infrequently editing files as a different user instead of myself. However, due to Prometheus and other things I'm editing more and more YAML these days, and YAML files have such a rigid and annoying requirement for their indentation and formatting that it's painful to edit them in a stock vi-like Vim setup. Initially I stuck 'modelines' at the top of most of the the Prometheus YAML files, but by default these are ignored if you're root so I had to remember to ':set' them by hand. Recently I decided that enough was enough, so I'd set our Prometheus server up so that YAML editing worked properly.
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How To Install VirtualBox on Linux Mint 21 - idroot
In this tutorial, we will show you how to install VirtualBox on Linux Mint 21. For those of you who didn’t know, VirtualBox is a free and open-source hypervisor for x86 and x86-64 virtualization, which the Oracle Corporation develops. Not only is VirtualBox an extremely feature-rich, high-performance product for enterprise customers, it is also the only professional solution that is freely available as Open Source Software under the terms of the GNU General Public License (GPL) version 2. It can be installed on operating systems, including Linux, Windows, Solaris, and macOS.
This article assumes you have at least basic knowledge of Linux, know how to use the shell, and most importantly, you host your site on your own VPS. The installation is quite simple and assumes you are running in the root account, if not you may need to add ‘sudo‘ to the commands to get root privileges. I will show you the step-by-step installation of a VirtualBox Virtualization on Linux Mint 21 (Vanessa).