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today's howtos

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  • R Programming Language

    R is an open-source programming language mostly used for statistical computing and data analysis and is available across widely used platforms like Windows, Linux, and MacOS. It generally comes with the command-line interface and provides a vast list of packages for performing tasks. R is an interpreted language that supports both procedural programming and object-oriented programming.

    In this R tutorial, we will learn about R programming language from basics to advance with a huge dataset of R core concepts, statistics, machine learning, etc explained with proper examples.

  • How to create a Singleton class properly in Java

    A Singleton class is a class of which only one instance exists. There is a need for such a design pattern for loggers, database connections and other scenarios.

    The main challenge comes when you want to implement a Singleton in a mutli-threaded environment and ensure that all the threads are synchronised when creating the Singleton instance.

  • Enable multi-factor authentication on OpenBSD

    In this article I will explain how to add a bit more security to your OpenBSD system by adding a requirement for user logging into the system, locally or by ssh. I will explain how to setup 2 factor authentication (2FA) using TOTP on OpenBSD

    What is TOTP (Time-based One time Password)

    When do you want or need this? It adds a burden in term of usability, in addition to your password you will require a device that will be pre-configured to generate the one time passwords, if you don't have it you won't be able to login (that's the whole point). Let's say you activated 2FA for ssh connection on an important server, if you get your private ssh key stolen (and without password, bouh!), the [attacker] will not be able to connect to the SSH server without having access to your TOTP generator.

  • Using pkgsrc on OpenBSD

    This quick article will explain how to install pkgsrc packages on an OpenBSD installation. This is something regulary asked on #openbsd freenode irc channel. I am not convinced by the relevant use of pkgsrc under OpenBSD but why not Smile

    I will cover an unprivileged installation that doesn't require root. I will use packages from 2020Q4 release, I may not update regularly this text so you will have to adapt to your current year.

  • How to update sudo version on Linux

    On Linux, the sudo command (short for "substitute user do" or "superuser do") is designed to allow a user to run a program with access capabilities of another user (most commonly the superuser "root"). sudo is commonly used to give selected users administrative control on a Linux system. Although sudo has built-in mechanisms to prevent misuse (e.g., security policies, input/output logging), the potential impact of any vulnerability in sudo command is still extremely high.

    For example, the latest heap buffer overflow vulnerability discovered in sudo (CVE-2021-3156) can trigger privilege escalation and allow any unprivileged user (those not in the sudoers list, or even nobody) to bypass password authentication and gain the root access. This vulnerability can easily be exploited as the second-stage attack once a low-level service account gets breached via brute-force attacks.

  • Creating namespaces in Linux using unshare - The Linux Juggernaut

    In a previous post, we talked about how kernel namespaces and cgroups form the building blocks of containerization in Linux. In this article, we will explore namespaces in more depth by demonstrating some examples of creating namespaces using the unshare command.

More in Tux Machines

digiKam 7.7.0 is released

After three months of active maintenance and another bug triage, the digiKam team is proud to present version 7.7.0 of its open source digital photo manager. See below the list of most important features coming with this release. Read more

Dilution and Misuse of the "Linux" Brand

Samsung, Red Hat to Work on Linux Drivers for Future Tech

The metaverse is expected to uproot system design as we know it, and Samsung is one of many hardware vendors re-imagining data center infrastructure in preparation for a parallel 3D world. Samsung is working on new memory technologies that provide faster bandwidth inside hardware for data to travel between CPUs, storage and other computing resources. The company also announced it was partnering with Red Hat to ensure these technologies have Linux compatibility. Read more

today's howtos

  • How to install go1.19beta on Ubuntu 22.04 – NextGenTips

    In this tutorial, we are going to explore how to install go on Ubuntu 22.04 Golang is an open-source programming language that is easy to learn and use. It is built-in concurrency and has a robust standard library. It is reliable, builds fast, and efficient software that scales fast. Its concurrency mechanisms make it easy to write programs that get the most out of multicore and networked machines, while its novel-type systems enable flexible and modular program constructions. Go compiles quickly to machine code and has the convenience of garbage collection and the power of run-time reflection. In this guide, we are going to learn how to install golang 1.19beta on Ubuntu 22.04. Go 1.19beta1 is not yet released. There is so much work in progress with all the documentation.

  • molecule test: failed to connect to bus in systemd container - openQA bites

    Ansible Molecule is a project to help you test your ansible roles. I’m using molecule for automatically testing the ansible roles of geekoops.

  • How To Install MongoDB on AlmaLinux 9 - idroot

    In this tutorial, we will show you how to install MongoDB on AlmaLinux 9. For those of you who didn’t know, MongoDB is a high-performance, highly scalable document-oriented NoSQL database. Unlike in SQL databases where data is stored in rows and columns inside tables, in MongoDB, data is structured in JSON-like format inside records which are referred to as documents. The open-source attribute of MongoDB as a database software makes it an ideal candidate for almost any database-related project. 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 the MongoDB NoSQL database on AlmaLinux 9. You can follow the same instructions for CentOS and Rocky Linux.

  • An introduction (and how-to) to Plugin Loader for the Steam Deck. - Invidious
  • Self-host a Ghost Blog With Traefik

    Ghost is a very popular open-source content management system. Started as an alternative to WordPress and it went on to become an alternative to Substack by focusing on membership and newsletter. The creators of Ghost offer managed Pro hosting but it may not fit everyone's budget. Alternatively, you can self-host it on your own cloud servers. On Linux handbook, we already have a guide on deploying Ghost with Docker in a reverse proxy setup. Instead of Ngnix reverse proxy, you can also use another software called Traefik with Docker. It is a popular open-source cloud-native application proxy, API Gateway, Edge-router, and more. I use Traefik to secure my websites using an SSL certificate obtained from Let's Encrypt. Once deployed, Traefik can automatically manage your certificates and their renewals. In this tutorial, I'll share the necessary steps for deploying a Ghost blog with Docker and Traefik.