today's howtos
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How to program a multitenant SaaS platform in Kubernetes | Red Hat Developer
In a previous article, I described how to create a SaaS platform in a Kubernetes cluster. This article takes a detailed look inside the demonstration project that accompanied that earlier article. The demonstration project is the code base shared by all tenants using the SaaS platform. This article describes the structure of the demonstration application. You'll also see how to get the code up and running for multiple containerized tenants in a Kubernetes cluster, and how to expose the service to clients.
A key aspect of SaaS architecture is a generic code base used by all tenants running in the Kubernetes cluster. The application logic used by each tenant is encapsulated in a Linux container image that's declared within the definition of the tenant's Kubernetes deployment. We'll see multiple examples of this generic approach and its benefits in this article.
The Linux container for each tenant is configured by setting a standard set of environment variables to values specific to that tenant. As shown in the previous article, adding a new tenant to the SaaS platform involves nothing more than setting up a database and creating a Kubernetes Secret, deployment, service, and route resources, all of which are assigned to a Kubernetes namespace created especially for the tenant. The result is that a single code base can support any number of tenants.
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Linux commands: Top 20 most important commands you need to know
There are thousands of commands that you can learn to use on a Linux system, but most users will find themselves executing the same few commands over and over. For users looking for a way to get started, we have compiled 20 of the most important Linux commands you need to know. These commands are some of the most useful, common, and essential tools that you will need in order to administer your Linux system or perform everyday tasks.
Every Linux distro has inherent access to a terminal, though the interface may look different depending on your desktop environment or configuration. Join us in this tutorial to learn about the 20 most important Linux commands. By the end, you will know enough to begin navigating your Linux terminal.
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How to kill process based on the port number in Linux
At any given moment your Linux system is running multiple processes simultaneously. Some of these processes have access to your network if they are being used to upload or download data. These processes typically bind themselves to a particular port number, and this can allow us to kill the process based on a port number.
The kill command is one way that system administrators can stop a process from running. However, the kill command only accepts a process ID as an argument. The pkill and killall commands are two more options, but these accept process names as arguments.
In order to kill a process based on its port number, we will need to use the fuser command, or use other command line tools in conjunction with the usual kill command. In this tutorial, we will show you multiple ways to kill a process based on its port number in Linux.
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How to print environment variables on Linux
The environment variables on a Linux system contain changing values that are referenced mainly by scripts and system programs. Environment variables differ from shell variables, because they can be accessed by any user or process across the entire system. In this tutorial, you will learn how to print environment variables on Linux.
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How to Install Brightness Controller on Linux Mint 21 LTS
At one point, Desktop Dimmer was a popular application to control screen brightness. However, the Desktop Dimmer application is now outdated and no longer works in Linux Mint 21. The best possible alternative to the Desktop Dimmer application is Brightness Controller, a graphical user interface (GUI) based application that works like Desktop Dimmer to help us control screen brightness. While Brightness Controller may not be an exact replacement for Desktop Dimmer, it does offer similar functionality. It is currently the best option for those looking for a screen brightness controller.
The following tutorial will teach you how to install Brightness Controller on Linux Mint 21 release series using a LaunchPAD APT PPA with the command line terminal.
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Important cURL Commands for Linux Developers
Curl has made data transfer between two machines connected on the same network much easier. As curl command adheres to a specific URL syntax to successfully transfer data over a network.
By default, no user interaction is needed during the execution of the curl command. Out of the numerous protocols it supports, the prominent ones are HTTP, HTTPS, SFTP, SCP, SMTP, SMTPS, FTP, FTPS, and FILE.
This article will walk us through some essential curl-related commands that can be useful to developers seeking a breakthrough under a Linux operating system environment.