You can use self-signed certificates for internal use or testing of HTTPS web services. This means you don’t need to buy a certificate from a commercial CA or generate a free Let’s Encrypt certificate. This article describes how to use the OpenSSL tool to issue a self-signed certificate in Linux, bind it to the Nginx web server and add it to the trusted certificate list on the user’s computer.
Continue reading “Creating a Self-Signed Certificate in Linux with OpenSSL”
If you specified an incorrect hostname when you installed the Proxmox VE node, you can change it.
Continue reading “How to Change the Hostname of a Proxmox VE Node”
Bash shell scripts in Linux are used in plaintext. Obfuscation allows you to hide a Bash script’s source code by compiling it into a binary. On Linux, you can use the shc tool to compile bash scripts. This tool can convert bash script code into C language and compile it. The output will be a binary file that can be run on almost any other Linux machine.
Continue reading “Linux: Compiling a Bash Script into Binary”
When the Linux operating system is installed on a computer, a unique machine identifier is automatically generated and saved in the /etc/machine-id file. This is similar to the Computer Security Identifier (Machine SID) in Windows.
Continue reading “How to Reset the Machine-ID of a Linux VM”
In this article, we will look at how to connect to a Microsoft SQL Server database from a Linux host (Ubuntu in this example) using an ODBC driver.
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In this article, we will look at how to completely disable system logging on Linux host (including /var/log, journald, and bash command history).
An error may occur when updating the apt deb package manager cache on Linux (Ubuntu or Debian distros):
$ apt-get updateW: 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
Continue reading “Fix: apt-get – there is no public key available”
In some cases, when connecting to a Linux host via SSH, there can be a very long delay before a password prompt appears (from 30 seconds up to 2 minutes).
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).
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).
Continue reading “Configure Network Settings on Ubuntu (Network Manager, Systemd and Netplan)”
