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Recently, after an OS updated and rebooted, I was not able to login to the desktop environment. When that happened, I thought to myself, “I wish I could just do a quick EBS snapshot like I would on the cloud before running any OS updates.” On my Linux desktop, the root volume is an LVM volume, I knew that snapshot was possible, but never tried to create one before. A friend at work encouraged that I should make use of it, and it was not that hard to get started....

Sometimes we want to see the content of a Systemd unit file. One obvious way to do it is to just cat/vim the content of the unit file directly. For example, to display the content of systemd-tmpfiles-clean.timer, we can perform the following step: ➜ systemctl status systemd-tmpfiles-clean.timer | grep Loaded Loaded: loaded (/usr/lib/systemd/system/systemd-tmpfiles-clean.timer; static) ➜ cat /usr/lib/systemd/system/systemd-tmpfiles-clean.timer; # SPDX-License-Identifier: LGPL-2.1-or-later # # This file is part of systemd. # # systemd is free software; you can redistribute it and/or modify it # under the terms of the GNU Lesser General Public License as published by # the Free Software Foundation; either version 2....

Today, I decided to have a quick revision on SELinux as it’s been a long while that I worked on any projects that required my attention to fiddling with SELinux. While I was looking for an sealert in /var/log/messages on my Fedora based desktop, I found a real issue that I need to fix. Like most of my blog posts, I’d like to start writing the post while I was about to solve the issue....

Earlier today, I have a need to check for a UDP opening port on a remote Linux server. And I felt blank in my brain, like I never done this before. Then I remember with TCP, I could use nc command to check it. Something like: ➜ nc -vz opnsense 22 Ncat: Version 7.92 ( https://nmap.org/ncat ) Ncat: Connection to 2400:a888:333:0:222:ffff:fe54:67de failed: TIMEOUT. Ncat: Trying next address... Ncat: Connection to 192....

This post documents what I learned about creating custom Axum extractor which can be used with the validator for validation. Create a new test project: ➜ cargo new request-validator cd request-validator The first crate to be added is axum for Axum framework. request-validator on  main [?] via 🦀 v1.79.0 ➜ cargo add axum Updating crates.io index Adding axum v0.7.5 to dependencies Features: + form + http1 + json + matched-path + original-uri + query + tokio + tower-log + tracing - __private_docs - http2 - macros - multipart - ws Updating crates....