Fix: apt-get – there is no public key available

An error may occur when updating the apt deb package manager cache on Linux (Ubuntu or Debian distros):

$ apt-get update

W: There is no public key available for the following key IDs: 467B942D3A79BD29
W: GPG error: https://repo.mysql.com/apt/ubuntu focal InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 467B942D3A79BD29

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Configure Local DNS Caching on Linux

On most modern Linux distros, you can enable the local caching of DNS queries by using the built-in systemd-resolved service. In this article, we will take a look at how to speed up the resolution of DNS queries by using systemd-resolved local client caching on Debian and Ubuntu. This allows you to reduce DNS resolution delays if you have an unstable network connection, when DNSSEC is enabled, and on hosts that make a large number of DNS queries (for example, mail servers).

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Configure Network Settings on Ubuntu (Network Manager, Systemd and Netplan)
Modern versions of Ubuntu offer many different ways to configure network settings, and it’s easy to get confused. In this article, we will have a look at how to configure network settings in Ubuntu using Network Manager, Systemd Networkd, Netplan, and the static configuration file /etc/network/interfaces (legacy way).

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How to Add and Change System Locale on Ubuntu and Debian

Linux localesettings determine the current operating system regional settings used in the terminal and GUI (such as date and time format, currency symbols, available character sets, etc.). This article looks at how to check or set locale settings on Linux distros (Ubuntu, Debian, Mint).

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Linux: Find Out Last System Reboot Time and Reason

Rebooting a Linux device can happen for several reasons. This could be a normal restart of the operating system by the user, an automatic installation of updates, kernel panics, physical hardware failures, software errors, or a power failure.

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Network Configuration with Systemd-networkd on Ubuntu/Debian

Systemd provides the systemd-networkd service that can be used to configure network settings on a Linux machine. In this article, we will look at how to use systemd-networkd to configure a network on Debian/Ubuntu distro as an example.

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Freeing Disk Space on Ubuntu Server

Many temporary and unused files are left on the Ubuntu drive after installing/uninstalling packages and dependencies. In addition, log files and old versions of the kernel can take up a fair amount of disk space. This article shows you how to clean up your Ubuntu Server hard drive by deleting temporary and unused files.

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