The author selected the Free Software Foundation to receive a donation as part of the Write for DOnations program. Introduction When the browser loads a page, it executes a lot of code to render the content. The code could be from the same origin as the root document, or a different origin. By default, the […]

The author selected the Internet Archive to receive a donation as part of the Write for DOnations program. Introduction Jenkins is a popular automation server, often used to orchestrate continuous integration (CI) and continuous deployment (CD) workflows. However, the process of setting up Jenkins itself has traditionally been a manual, siloed process for the system

The author selected Girls Who Code to receive a donation as part of the Write for DOnations program. Introduction Docker can be an efficient way to run web applications in production, but you may want to run multiple applications on the same Docker host. In this situation, you’ll need to set up a reverse proxy.

Introduction HTML provides a select element that allows end-users to choose from a dropdown menu of options. However, there may be situations where a select menu can benefit from additional user experience niceties, like allowing a user to filter available choices. React Select is a highly configurable select menu library for React that features dynamic

Introduction Flex Layout is a component engine that allows you to create page layouts using CSS Flexbox with a set of directives available to use in your templates. The library is written in pure TypeScript, so no external stylesheets are needed. It also provides a way to specify different directives at different breakpoints to create

How to Create PHP Development Environments with Docker Compose Workshop Kit Materials This workshop kit is designed to help a technical audience become familiar with Docker Compose and learn to set up a working development environment for a Laravel application using containers. The aim is to provide a complete set of resources for a speaker

The author selected the COVID-19 Relief Fund to receive a donation as part of the Write for DOnations program. Introduction SSH uses passwords for authentication by default, and most SSH hardening instructions recommend using an SSH key instead. However, an SSH key is still only a single factor, though a much more secure factor. The

The author selected the COVID-19 Relief Fund to receive a donation as part of the Write for DOnations program. Introduction SSH uses passwords for authentication by default, and most SSH hardening instructions recommend using an SSH key instead. However, an SSH key is still only a single factor, though a much more secure factor. The

Introduction In this article, you will examine how to implement Context API and the React Hook useContext() in your React project. The Context API is a React structure that allows you to share specific data from all levels of your application and aids in solving prop-drilling. React Hooks are functions that serve as a modular

Introduction While many users need the functionality of a database management system like MariaDB, they may not feel comfortable interacting with the system solely from the MariaDB prompt. phpMyAdmin was created so that users can interact with MariaDB through a web interface. In this guide, we’ll discuss how to install and secure phpMyAdmin so that

The author selected Wikimedia Foundation Inc. to receive a donation as part of the Write for DOnations program. Introduction Seafile is an open source, self-hosted, file synchronization and sharing platform. Users can store and optionally encrypt data on their own servers with storage space as the only limitation. With Seafile you can share files and

How To Build a Website With HTML Workshop Kit Materials This workshop kit is designed to help an instructor guide an audience without a background in web development through the steps of recreating and personalizing this HTML website from start to finish in roughly ninety minutes. Participants will finish the workshop with an understanding of

The author selected the COVID-19 Relief Fund to receive a donation as part of the Write for DOnations program. Introduction Python includes a number of built-in functions—these are global Python functions that can be called from any Python code without importing additional modules. For example, you can always call the print built-in function to output

Introduction A sticky sidebar is a web design technique to keep the sidebar on the screen even if the user has scrolled past the position where it initially displayed. This is useful for making sub-navigation easily accessible, highlighting your content in your sidebar more as a user scrolls, and potentially increasing your ad impressions, clicks,

Introduction Imagine you are working on an API endpoint to create a new user. User data—such as firstname, lastname, age, and birthdate—will need to be included in the request. A user mistakenly entering their name in as the value for the age field when you are expecting a numeric value would not be desirable. A

Introduction Loading indicators improve UX (user experience) in any application—web or mobile. These animations provide feedback to the user that an action is being carried out and a result will return shortly. In web applications, there are two major events that need loaders: Network requests like navigating to a different page or an AJAX request.

Introduction You may have noticed that on many websites you can now toggle between dark and light themes. This is often done using CSS custom properties (aka CSS variables). In this tutorial you’ll see how you can achieve something similar using only CSS and a touch of JavaScript. To learn more about how this code

Introduction While running a WordPress installation through a hosting service can be a convenient way to start a website, it’s not without security vulnerabilities that may sometimes be hard to troubleshoot. Brute-force attacks, cyberattacks that rapidly work to guess and access personal information like logins or passwords, happen when these vulnerabilities are exploited. Brute-force attacks

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction ClickHouse is an open source, column-oriented analytics database created by Yandex for OLAP and big data use cases. ClickHouse’s support for real-time query processing makes it suitable for applications that require sub-second analytical

The author selected the COVID-19 Relief Fund to receive a donation as part of the Write for DOnations program. Introduction Mahara is an open-source ePortfolio and social networking system that bills itself as a “learner-centered personal learning environment.” Mahara is especially popular in academic institutions where it provides learners a platform to curate and share

Introduction The latest alpha release of React introduced a new concept called Hooks. Hooks were introduced to React to solve common problems. However, they primarily serve as an alternative for classes. With Hooks, you can create functional components that use state and lifecycle methods. Hooks are currently available in React v16.7.0-alpha. There are no plans

The author selected the Open Source Initiative to receive a donation as part of the Write for DOnations program. Introduction Laravel is a free, open source PHP framework, based on Symfony and used for creating web applications. SendGrid is a cloud-based SMTP provider that allows you to send email without having to maintain email servers.

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction Sandboxing is a computer security technique that focuses on isolating a program or process from parts of a system that it does not need to interact with during normal operation. When a new

The author selected the Internet Archive to receive a donation as part of the Write for DOnations program. Introduction GoAccess is a tool for monitoring web server logs in realtime. It’s written in C and uses the popular ncurses library for its dashboard interface, which can be accessed directly from the command-line. This is great

Introduction In this article, we’ll learn how to use most methods available in the Node.js console class more effectively. Prerequisites This tutorial was verified with Chrome browser version 70.0.3538.77 and Node.js version 8.11.3. Using console.log, console.info, and console.debug The console.log method prints to standard out, whether this is the terminal or browser console.It outputs strings

Introduction Laravel as a framework either for building websites or a container to build APIs (lumen) has evolved as a developer’s framework of choice. Laravel comes with a lot of growing features – take for example Laravel’s events. Events in Laravel used to be a simple pub-sub library, but now Laravel events can broadcast all

If you are constantly needing to SSH into multiple servers, it can real daunting to remember all the different usernames, hostnames, IP addresses, and even sometimes custom private keys to connect to them. It’s actually extremely easy to create command line shortcuts to solve this problem. There’s two major ways to do it, and we’ll

Introduction Neo4j is a graph database that records relationships between data nodes, whereas traditional relational databases use rows and columns to store and structure data. Since each node stores references to all the other nodes that it is connected to, Neo4j can encode and query complex relationships with minimal overhead. Prerequisites To follow this tutorial,

Introduction There is a kind of animation that has not stopped increasing its presence in the most modern and original websites: the animations based on the scroll event of JavaScript. This trend literally exploded when the parallax effects appeared, and since then its use has become more frequent. But the truth is that you must

Introduction Reduce is a method that can be difficult to understand especially with all the vague explanations that can be found on the web. There are a lot of benefits to understanding reduce as it is often used in state management (think Redux). The signature for the reduce array method in JavaScript is: arr.reduce(callback, initialValue);

Introduction Promises give us an easier way to deal with asynchrony in our code in a sequential manner. Considering that our brains are not designed to deal with asynchronicity efficiently, this is a much welcome addition. Async/await functions, a new addition with ES2017 (ES8), help us even more in allowing us to write completely synchronous-looking

Strings can be converted to integers by using the int() method. If your string does not have decimal places, you’ll most likely want to convert it to an integer by using the int() method. Let’s use an example of the user sammy keeping track of lines of code written each day. We may want to

We can convert numbers to strings using the str() method. We’ll pass either a number or a variable into the parentheses of the method and then that numeric value will be converted into a string value. To convert the integer 12 to a string value, you can pass 12 into the str() method: str(12) Output’12’

Introduction CSS has several options for which units to use when determining the size of various CSS properties. Learning all your options for CSS units can be key for styling in a way that’s easy to manage and looks great on any screen. What is a CSS Unit? A CSS unit determines the size of

Introduction vertical-align defines the vertical alignment for the content of a table cell or for an inline element against the rest of the inline flow. vertical-align can take a % or length value, or it can take one of the following 8 keywords: baseline: The default. Baseline of the element aligned to the baseline of

white-space is a CSS property that helps control how whitespace and line breaks within an element’s text are treated. The white-space property can take these values: normal: The default value. Multiple whitespaces are collapsed into one. The text wraps to the next line when needed. nowrap: Multiple whitespaces are collapsed into one, but the text

In Web Design and Development, like most fields, you have to evolve to keep up with the times. This is especially true with new features that get added to one of a designers most often used tools, like CSS. CSS3, the latest specification for CSS, has several new features designers can start taking advantage of

Drop caps have been used for a long time with print media to give panache to the first letter of the first paragraph of a section or chapter. These drop caps help draw attention and entice the reader, and it’s often a good occasion to use a very stylized font because it’s applied on only

Introduction When it comes to validating the content of input fields on the frontend, things are much easier now than they they used to be. We can use the :required, :optional, :valid and :invalid pseudo-classes coupled with HTML5 form validation attributes like required or pattern to create very visually engaging results. These pseudo-classes work for

The author selected the COVID-19 Relief Fund to receive a donation as part of the Write for DOnations program. Introduction Kubernetes and the microservice architectures that it enables can create very efficient and scalable systems. But problems arise when one of these microservices develops performance problems. Typically, we first notice that response times from our

Introduction Selecting a parent element has long been impossible to do using just CSS, but a pseudo-class, :focus-within, changes that story somewhat. It allows to style an element when it has focus, but also when any of its inner elements (descendants) have focus. A prime example is with a form where you’d want a container

In this article, you’ll learn about how to use the z-index CSS property… The only way to break into the 3rd dimension with CSS! Most of the time when you’re styling things with CSS, it’s on a 2D plane. HTML elements are placed horizontally/vertically on the page like stacking blocks in Tetris. The z-index changes

Now that that we have custom properties in CSS, we pretty much have full power over our own variables in CSS. But even before those become helpful, we can use a keyword available since the CSS Color Module Level 3, currentColor, to keep colors consistent within elements. currentColor acts like a variable for the current

Font variations is a new set of features defined as part of the OpenType specification. It allows for font files to contain multiple variation of a font within a single file, called a variable font. This in turns allows the use of one font file on the web that can achieve multiple font styles. On

Introduction In programming, counters are variables that hold a value that increments according to customizable rules. They have many purposes, such as helping to keep tabs on loops by storing the number of times the loop has been executed. Though routinely used in programming languages, counters have not traditionally been included in the syntax for

Introduction React Navigation is a popular library for routing and navigation in a React Native application. This library helps solve the problem of navigating between multiple screens and sharing data between them. At the end of this tutorial, you will have a rudimentary social network. It will display the number of connections a user has

Introduction When looking to migrate data from one Redis instance to another, there are a number of methods one could employ, such as replication or snapshotting. However, migrations can get more complicated when you’re moving data to a Redis instance managed by a cloud provider, as managed databases often limit how much control you have

The author selected the Electronic Frontier Foundation to receive a donation as part of the Write for DOnations program. Introduction Cloudflare is a service that sits between the visitor and the website owner’s server, acting as a reverse proxy for websites. Cloudflare provides a Content Delivery Network (CDN), as well as DDoS mitigation and distributed

Introduction Form validation, also known as form field validation, ensures that a user fills out all required fields in a web form. If a field has an invalid value, it will display an error message and prevent form submission until the values satisfy all the rules. Template-driven validation is a type of form validation where

Introduction Snapshot testing allows you to ensure your output continues to behave as expected. This is useful because as you revisit your code to make updates over time, there is an increased likelihood that those changes may cause something to break. Unlike strict Test Driven Development (TDD), where the standard practice is to write failing

The author selected the Diversity in Tech Fund to receive a donation as part of the Write for DOnations program. Introduction DDEV is an open-source tool that uses Docker to build local development environments for many different PHP frameworks. Using the power of containerization, DDEV can greatly simplify how you work on multiple projects that

Introduction A managed Redis instance can provide benefits like high availability and automated updates. However, any time you make a connection to a remote database server, you run the risk of malicious actors sniffing the sensitive information you send to it. redis-cli, the Redis command line interface, doesn’t natively support connections over TLS, a cryptographic

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction Even with the growing popularity of cloud services, the need for running native applications still exists. By using noVNC and TigerVNC, you can run native applications inside a Docker container and access them

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction Even with the growing popularity of cloud services, the need for running native applications still exists. By using noVNC and TigerVNC, you can run native applications inside a Docker container and access them

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction Mattermost is an open source collaboration and messaging platform created with security and configurability in mind providing comparable functionality to Discord or Slack. It offers group, threaded and one-to-one messaging, unlimited search history

Introduction Dragging-and-dropping is a common user interaction that you can find in many graphical user interfaces. There are pre-existing JavaScript libraries for adding a drag-and-drop feature to your app. However, there may be situations where a library is not available or introduces an overhead or dependency that your project does not need. In these situations,

The author selected the Apache Software Foundation to receive a donation as part of the Write for DOnations program. Introduction When you have critical websites you’ll want to know when they are experiencing any issues so you can fix them before there’s an impact on your users. One way to receive notifications is to set

Introduction This article will teach you how to render an array in React and the best practices to use when rendering different elements within components. One of the advantages of using a modern web language like JavaScript is that you can quickly automate the generation of HTML chunks. Using something like a loop against an

Introduction The Python built-in filter() function can be used to create a new iterator from an existing iterable (like a list or dictionary) that will efficiently filter out elements using a function that we provide. An iterable is a Python object that can be “iterated over”, that is, it will return items in a sequence

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction Postfix is a mail transfer agent (MTA), an application used to send and receive email. It can be configured so that it can be used to send emails by local application only. This

Download the Complete eBook! How To Manage a Redis Database eBook in EPUB format How To Manage a Redis Database eBook in PDF format Introduction to the eBook This book aims to provide an approachable introduction to Redis concepts by outlining many of the key-value store’s commands so readers can learn their patterns and syntax,

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction System logs are an extremely important component of managing Linux systems. They provide an invaluable insight into how the systems are working and also how they are being used because, in addition to

The author selected Software in the Public Interest to receive a donation as part of the Write for DOnations program. Introduction ERPNext is an Enterprise Resource Planning (ERP) suite that leverages the power and flexibility of open-source technologies. It excels at managing core business processes such as finance, sales, human resources, manufacturing, purchases, services, helpdesk

The author selected Software in the Public Interest (SPI) to receive a donation as part of the Write for DOnations program. Introduction Usually, Linux-based servers don’t come with a graphical user interface (GUI) pre-installed. Whenever you want to run GUI applications on your instance, the typical solution is to employ Virtual Network Computing (VNC). Unfortunately,

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction Discourse is an open-source discussion platform. You can use Discourse as a mailing list, a discussion forum, or a long-form chat room. In this tutorial, you will install Discourse in an isolated environment

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction Discourse is an open-source discussion platform. You can use Discourse as a mailing list, a discussion forum, or a long-form chat room. In this tutorial, you will install Discourse in an isolated environment

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction System logs are an extremely important component of managing Linux systems. They provide an invaluable insight into how the systems are working and also how they are being used because, in addition to

Introduction Progressive web apps are web applications built with technologies that make them behave like native apps. A benefit of progressive web apps is the ability to work smoothly when network coverage is unreliable. Also, unlike native apps, no installation is required, but they are faster than typical web apps. In this article, you’ll build

Introduction In this quickstart guide, we’ll install a LAMP stack on an Ubuntu 20.04 server. For a more detailed version of this tutorial, with more explanations of each step, please refer to How To Install Linux, Apache, MySQL, PHP (LAMP) Stack on Ubuntu 20.04 Prerequisites To follow this guide, you’ll need access to an Ubuntu

Introduction Django is a free and open-source web framework written in Python that adheres to the model template view (MTV) software architectural pattern. The MTV pattern is Django’s take on the model–view–controller (MVC) pattern. According to the Django Software Foundation, the model is the single definitive source of your data, the view describes the data

Introduction A Virtual Private Network (VPN) allows you to traverse untrusted networks as if you were on a private network. It gives you the freedom to access the internet safely and securely from your smartphone or laptop when connected to an untrusted network, like the WiFi at a hotel or coffee shop. When combined with

The author selected the Open Internet/Free Speech Fund to receive a donation as part of the Write for DOnations program. Introduction It is nearly impossible to build websites that work perfectly the first time without errors. For that reason, you need to test your web application to find these errors and work on them proactively.

The author selected Girls Who Code to receive a donation as part of the Write for DOnations program. Introduction A Binary Large Object (BLOB) is a MySQL data type that can store binary data such as images, multimedia, and PDF files. When creating applications that require a tightly-coupled database where images should be in sync

Introduction Forgetting passwords happens to the best of us. If you forget or lose the root password to your MySQL or MariaDB database, you can still gain access and reset the password if you have access to the server and a sudo-enabled user account. This tutorial will cover resetting the root password for older and

Introduction Nginx is one of the most popular web servers in the world and is responsible for hosting some of the largest and highest-traffic sites on the internet. It is more resource-friendly than Apache in most cases and can be used as a web server or reverse proxy. In this guide, we’ll explain how to

The author selected the COVID-19 Relief Fund to receive a donation as part of the Write for DOnations program. Introduction BGP (Border Gateway Protocol) is one of the core protocols responsible for routing packets across the internet, so when it goes wrong, significant outages can occur. For example, in 2019, a small ISP made a

Introduction One way to guard against out-of-memory errors in applications is to add some swap space to your server. In this guide, we will cover how to add a swap file to an Ubuntu 20.04 server. What is Swap? Swap is a portion of hard drive storage that has been set aside for the operating

Vuex is an easy to use and performant solution to handle state management. It makes it a breeze to manage large-scale Vue.js applications and ensures a predictable way to mutate the state by exposing a store. You may already know about Vuex, but if you don’t Joshua Bemenderfer gave us a great introduction. You can

The author selected United Nations Foundation to receive a donation as part of the Write for DOnations program. The original WordPress version of this tutorial was written by Kathleen Juell. Introduction Drupal is a content management system (CMS) written in PHP and distributed under the open-source GNU General Public License. People and organizations around the

Introduction The Apache HTTP server is the most widely-used web server in the world. It provides many powerful features including dynamically loadable modules, robust media support, and extensive integration with other popular software. In this guide, you will install an Apache web server with virtual hosts on your CentOS 8 server. Prerequisites You will need

Introduction Python is a flexible and versatile programming language, with strengths in scripting, automation, data analysis, machine learning, and back-end development. This tutorial will walk you through installing Python and setting up a programming environment on an Ubuntu 20.04 server. For a more detailed version of this tutorial, with more thorough explanations of each step,

###Introduction Python is a flexible and versatile programming language, with strengths in scripting, automation, data analysis, machine learning, and back-end development. This tutorial will walk you through installing Python and setting up a programming environment on an Ubuntu 18.04 server. For a more detailed version of this tutorial, with better explanations of each step, please

The author selected the Tech Education Fund to receive a donation as part of the Write for DOnations program. Introduction A service mesh is a dedicated infrastructure layer that helps administrators handle service-to-service communication. Offering many powerful tools, these service meshes can make your system safer, more reliable, and more visible too. A service mesh

Introduction SSH, or secure shell, is an encrypted protocol used to administer and communicate with servers. When working with an Ubuntu server, chances are you will spend most of your time in a terminal session connected to your server through SSH. In this guide, we’ll focus on setting up SSH keys for an Ubuntu 20.04

A previous version of this article was written by Toli. Introduction Elasticsearch is a platform for distributed search and analysis of data in real time. It is a popular choice due to its usability, powerful features, and scalability. This article will guide you through installing Elasticsearch, configuring it for your use case, securing your installation,

Introduction A LEMP software stack is a group of open source software that is typically installed together to enable a server to host dynamic websites and web apps. This term is actually an acronym which represents the Linux operating system, with the ENginx web server (which replaces the Apache component of a LAMP stack). The

The author selected Open Internet/Free Speech Fund to receive a donation as part of the Write for DOnations program. Introduction Ampache is an open-source music streaming server that allows you to host and manage your digital music collection on your own server. Ampache can stream your music to your computer, smartphone, tablet, or smart TV.

Introduction A “LAMP” stack is a group of open source software that is typically installed together to enable a server to host dynamic websites and web apps written in PHP. This term is an acronym which represents the Linux operating system, with the Apache web server. The backend data is stored in a MariaDB database

Introduction A Certificate Authority (CA) is an entity responsible for issuing digital certificates to verify identities on the internet. Although public CAs are a popular choice for verifying the identity of websites and other services that are provided to the general public, private CAs are typically used for closed groups and private services. Building a

While I’m sure we can all agree that queues are the coolest things since sliced bread, we can actually do much better by mixing them with a variation of trees called heaps. With heaps we can structure our data into a more intelligent queue that’s sorted by importance rather than order. Concepts Unlike with binary

Introduction When you first start using a fresh Linux server, adding and removing users is often one of first things you’ll need to do. In this guide, we will cover how to create user accounts, assign sudo privileges, and delete users on a CentOS 8 server. Prerequisites This tutorial assumes you are logged into a

Introduction MariaDB is an open-source database management system, commonly used as an alternative for the MySQL portion of the popular LAMP (Linux, Apache, MySQL, PHP/Python/Perl) stack. It is intended to be a drop-in replacement for MySQL. In this tutorial, we will explain how to install the latest version of MariaDB on a CentOS 8 server.

Introduction Relational database management systems are a key component of many websites and applications. They provide a structured way to store, organize, and access information. PostgreSQL, also known as Postgres, is a relational database management system that provides an implementation of Structured Query Language, better known as SQL. It’s used by many popular projects, both

The author selected the COVID-19 Relief Fund to receive a donation as part of the Write for DOnations program. Introduction The firewall is arguably one of the most important lines of defense against cyber attacks. The ability to configure a firewall from scratch is an empowering skill that enables the administrator to take control of

Introduction firewalld is firewall management software available for many Linux distributions, which acts as a frontend for Linux’s in-kernel nftables or iptables packet filtering systems. In this guide, we will show you how to set up a firewalld firewall for your CentOS server, and cover the basics of managing the firewall with the firewall-cmd administrative

When I first dived into JavaScript and programming; I never really thought about immutable data. I would say animal is panda, then animal is lion. var animal = ‘panda’;animal = ‘lion’; I was free to do whatever I wanted with my data! But… things changed… I grew up. People started telling me: “you should always

Static site generators are very à la mode right now and with the JAMStack becoming a more-than-viable alternative for many web projects these days, it’s no wonder! JAMStack or not, static site generators (SSGs) offer some major advantages over more traditional CMSs, and when it comes to SSGs, there are plenty of options to choose

Today we’ll be covering how a number of formatting options available with the vue-i18n plugin for internationalization (i18n). We’ll also be covering how to handle fallbacks when no string is available for a locale. We’ll be using the vue-i18n plugin written by Kazuya Kawaguchi, and this article is building up from this previous one, which

Introduction The sudo command provides a mechanism for granting administrator privileges — ordinarily only available to the root user — to normal users. This guide will show you how to create a new user with sudo access on CentOS 8, without having to modify your server’s /etc/sudoers file. Note: If you want to configure sudo

Introduction When running multiple services and applications on a Kubernetes cluster, a centralized, cluster-level logging stack can help you quickly sort through and analyze the heavy volume of log data produced by your Pods. One popular centralized logging solution is the Elasticsearch, Fluentd, and Kibana (EFK) stack. Elasticsearch is a real-time, distributed, and scalable search

Introduction The LEMP software stack is a group of software that can be used to serve dynamic web pages and web applications. The name “LEMP” is an acronym that describes a Linux operating system, with an (E)Nginx web server. The backend data is stored in a MariaDB database and the dynamic processing is handled by

Introduction Snapshot testing is a type of testing in Jest which monitors regression in your code and also serves as an integration test. The first means that if you add more code to your project and something small breaks, snapshot testing can catch it. The second means that snapshot testing is a way of making

Introduction Nginx Nginx is a fast and lightweight alternative to the sometimes overbearing Apache 2. However, Nginx just like any kind of server or software must be tuned to help attain optimal performance. Requirements A fresh Debian 7 droplet with the intial setup completed. The droplet must also have a freshly installed and configured Nginx

Download the Complete eBook! Making Servers Work: A Practical Guide to System Administration eBook in EPUB format Making Servers Work: A Practical Guide to System Administration eBook in PDF format Introduction to the eBook This book highlights practical sysadmin skills, common architectures that you’ll encounter, and best practices that apply to automating and running systems

The author selected Open Sourcing Mental Illness to receive a donation as part of the Write for DOnations program. Introduction A MySQL transaction is a group of logically related SQL commands that are executed in the database as a single unit. Transactions are used to enforce ACID (Atomicity, Consistency, Isolation, and Durability) compliance in an

Vue is best used when with its templating features. It becomes very intuitive to build fancy user interfaces. Take its directives, for example, which refers to tag attributes with the v- prefix. You could have a variable url in your Vue instance that your anchor tag uses as its href. That would look like this:

In the last post, More Advanced Routing with Vue, we covered using Transitions with Vue Router. This time we’ll cover Data Fetching with Vue Router. Data Fetching allows us to load asynchronous data in our routed components. We can also specify whether data is fetched before or after a component is loaded. Both of these

Introduction Jest is a popular JavaScript testing framework that comes packed with a lot of goodies for developers. If you’re completely unfamiliar with how Jest works in general, I recommend you start with this introduction. Once you understand the basics of Jest, you’re ready to jump right in and see how it can be used

not quite… Better! The cookie is one of the web’s favorite emoji and it’s also one of web’s most important technology. Let’s take a look at what it’s all about, shall we? The Basics of Browser Cookies Browser cookies were introduced to the web in order to keep persistent information about the user. The first

Last time we covered advanced Vue Router topics we discussed Navigation Guards and Redirects. This time we’ll be tackling how to implement Vue Router Transitions. We’ve already covered Vue Transitions in Understanding Vue.js Transitions, so we’ll use that as a starting point. Combining Vue Router with transitions will allow us to customize the user’s experience

Having your datasets arranged all willy-nilly will only add more time and resources to manage and search through. Whether your data is sorted or not will directly affect what search methods you can use and can mean the difference between a search taking a million operations or taking 10, like with Binary Search. For simplicity’s

The author selected the Electronic Frontier Foundation Inc to receive a donation as part of the Write for DOnations program. Introduction Security threats are continually becoming more sophisticated, so developers and systems administrators need to take a proactive approach in defending and testing the security of their applications. A common method for testing the security

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction With developer tools moving to the cloud, adoption of cloud IDE (Integrated Development Environment) platforms is growing. Cloud IDEs are accessible from every type of modern device through web browsers, and they offer

Introduction Docker is a great tool for automating the deployment of Linux applications inside software containers, but to take full advantage of its potential each component of an application should run in its own individual container. For complex applications with a lot of components, orchestrating all the containers to start up, communicate, and shut down

The author selected the the Apache Software Foundation to receive a donation as part of the Write for DOnations program. Introduction Pagination is the concept of constraining the number of returned rows in a recordset into separate, orderly pages to allow easy navigation between them, so when there is a large dataset you can configure

JavaScript comes with some pretty handy out-of-the-box tools for searching through an array. But with a large data set the O(n) methods like indexOf, find, or a basic loop just aren’t the best or even feasible. Instead, we can use Binary search to go over an array without looking at what we obviously don’t need,

If you’re familiar with Redux or Vuex, then the Svelte stores offer a similar feature for state management. If your app is getting complicated, then it becomes difficult for components to relay data between themselves. Moving it to a global data store is a better option. Here, we’ll look at two store options that Svelte

In this article, you’re going to learn how to use recursive programming, what it is, and how to optimize it for use in algorithms. We’ll be using JavaScript as our programming language of choice to understand the concept of recursion. Prerequisites I’ll be using Big O Notation to compare optimization strategies, which you can brush

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction With developer tools moving to the cloud, adoption of cloud IDE (Integrated Development Environment) platforms is growing. Cloud IDEs are accessible from every type of modern device through web browsers, and they offer

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction With developer tools moving to the cloud, adoption of cloud IDE (Integrated Development Environment) platforms is growing. Cloud IDEs are accessible from every type of modern device through web browsers, and they offer

If you have ever created a web application which requires different features (like push notifications, webcam access, midi access), you probably noticed that their APIs look very different. // for the geolocation API you need to call getCurrentPosition to check if geolocation is accessiblenavigator.geolocation.getCurrentPosition(gotLocation, didNotGetLocation);// for notifications we can directly check on the Notification objectif

The idea behind a CLI (Command Line Interface) is to use simple, editable commands in order to produce a greater output. The Vue CLI is no different. When a new project begins, the last thing a developer should worry about is project scaffolding. Luckily, the Vue team has bundled scaffolding, prototyping, and a variety of

The author selected the Electronic Frontier Foundation Inc to receive a donation as part of the Write for DOnations program. Introduction DNSControl is an infrastructure-as-code tool that allows you to deploy and manage your DNS zones using standard software development principles, including version control, testing, and automated deployment. DNSControl was created by Stack Exchange and

Introduction Ansible is a configuration management tool that is designed to automate controlling servers for administrators and operations teams. With Ansible you can use a single central server to control and configure many different remote systems using SSH and Python as only requirements. Ansible carries out tasks on servers that it manages based on task

Since Gatsby handles our routes for us, that leaves us with nowhere to wrap our app with a Redux store or provider. In this article we’ll learn a clever trick to get around that. For the sake of simplicity, all of the examples will be using React’s Context API for our state management to save

Introduction code-server is Microsoft Visual Studio Code running on a remote server and accessible directly from your browser. This means that you can use various devices, running different operating systems, and always have a consistent development environment on hand. In this tutorial, you will set up the code-server cloud IDE platform on your Ubuntu 18.04

Introduction Server automation now plays an essential role in systems administration, due to the disposable nature of modern application environments. Configuration management tools such as Ansible are typically used to streamline the process of automating server setup by establishing standard procedures for new servers while also reducing human error associated with manual setups. Ansible offers

The author selected the Free Software Foundation to receive a donation as part of the Write for DOnations program. Introduction ProxySQL is a SQL-aware proxy server that can be positioned between your application and your database. It offers many features, such as load-balancing between multiple MySQL servers and serving as a caching layer for queries.

Introduction The path element of SVG can be used to create innovative animations for the frontend of your website or web application. In this tutorial, we will show you how to set up your HTML, CSS, and JavaScript to to move elements along an SVG path using the PathSlider library. By following the entire tutorial,

If you have been building for the web for a little while, you would have like me encountered at least some issues when making swipers – for some reason, they always seem to have a mind of their own for a while and they come around. It’s either, the swiper isn’t as responsive as you

Introduction Web development often involves the use of different development stacks, including the LAMP stack, the MEAN stack, the MERN stack, etc. JAMstack is another stack that offers some unique benefits to developers. This article will discuss those benefits and some general definitions and terms in order to provide an introduction to the JAMstack. What

Introduction Laravel form requests are special classes that extend the functionality of regular request classes, enabling advanced validation features. Form requests also help to keep your controller actions a lot cleaner, because you can move all your validation logic to the form request class. Another benefit is that it allows you to filter requests before

Introduction With the adoption of the Redux JavaScript library, the Reason syntax extension and toolchain, and the Cycle JavaScript framework, functional programming with JavaScript is becoming increasingly relevant. Two important ideas with roots in functional thought are currying, which transforms a function of multiple arguments into a series of function calls, and partial application, which

Many web applications include an in-app notification system that will notify you instantly when someone carries out an action related to you or your account. On Facebook, you will be notified when someone likes your status, or when someone comments on your profile. This tutorial will guide you through replicating this functionality by creating a

Introduction In this article we’ll use the Docker Plugin for Visual Studio Code. Docker allows us to package our applications into images and run them as containers on any platform that has Docker installed. We’ll use this plugin with two developer stacks: Node.js and Go. Installation You need to have docker installed on your work

Introduction When creating a professional website, using an image carousel to showcase your portfolio will display your experience with front-end development in a fun and creative way. This tutorial will walk you through the essential steps of creating and styling this web page component. You will write the HTML, style it with CSS, and use

As a developer, chances are you spend most of your time in your terminal, typing in commands to help you get around some tasks. Some of these commands come built into your Operating System, while some of them you install through some third party helper such as npm, or brew, or even downloading a binary

Introduction GraphQL gained popularity in terms of front-end development due to the various advantages it offers over REST APIs. However, setting up your own GraphQL server is both error-prone and complicated. Due to this, managed services such as Prisma have been made to manage your GraphQL server, allowing you to focus on the development of

Introduction In this tutorial, we will use the React frontend Javascript framework and CSS Grid to build an infinite scroll image gallery, using the Unsplash API to embed the photographic images. Using a codepen coding challenge from Scotch.io as a base for our code, we will use React.js to build out the interface, Axios to

Introduction Building accessible applications or websites is not the norm today. This is because the idea of accessibility is known to most developers, while in actual sense it is often neglected and not a common practice today in the world of web development. According to World Bank Statistics about 15% of the world population experience

###IntroductionIf you hate stubbing out Python classes, here’s how you can create an extension in Visual Studio Code to do it for you. In this article, you’ll see how to create that extension. We will use several techniques to do so. Prompting User Input Array Map and Join Functions ES6 Template Literals Writing to the

Introduction When you’re building a web site, you’ll often want to share your Social Media accounts for visitors to follow. In this tutorial, you’ll create a Social Follow component in React, using the social media icons provided by Font Awesome. When you’re done, you’ll have a component that looks like this: Prerequisites Node.js installed locally,

When you require an easy to deploy setup, it is possible to build static sites with React using Gatsby.js. These provide good speed and smooth developer experience. Gatsby has been consistently growing with developers using it for blog, marketing, and e-commerce sites. Every time, you build a site you can help search engine’s crawlers to

Introduction Extension Packs in Visual Studio Code are useful when you want to install a collection of related extensions. In this article, you’ll create an Extension Pack so you can share your collection of extensions with other developers. Installing the Tools To get started creating an Extension Pack, you will need to install the Yeoman

Introduction There are tons of tools out there that help you make sure your app is functioning perfectly, but how do you catch bugs that are purely visual? In the example above, the button still works, and the text is actually still there, but the link somehow changed to be the same color as the

Introduction In this tutorial, you will create a bouncing page loader using CSS3 animation keyframes. It will show you how to style HTML for a loading page, create animation keyframes, and use animation delay with keyframes. Here’s what you’ll be making by the end of this tutorial: Or click use the following CodePen link to

This is a continuation of a series on GraphQL Actions. The previous tutorial explored GraphQL Queries. This time, we will take a closer look at Mutations. There’s a lot of similarities in the way GraphQL Queries and Mutations work, however, Mutations are more about mutating data than querying for it. In this article, we’ll dive

Introduction In this tutorial, we’ll go over how to handle file uploads in GraphQL by building a full-stack app. This tutorial will be divided into two main sections: building the GraphQL API, and creating the frontend app. The GraphQL API will be built using Apollo Server and the frontend app will be built with Vue.js

###IntroductionOn frontend codebase projects, requirements and sometimes scopes can change frequently. When requirements change and you adjust the stylesheet or extend the styles of a selector in a particular page, such changes often affects other views that share similar styles. This may lead to many hours of specificity wars while trying to override styles. That

Introduction With ES6, there were many updates to the JavaScript, including the spread operator, object destructuring, new type of variables, and more. One of the most notable changes were arrow functions, a new and concise way to write functions. With arrow functions, you can define a readable and concise function in one line. In this

###IntroductionIn the last few years JavaScript frameworks have completely changed the way we build apps, and React has had its fair share of the conversion process. Optimizing page load time is important because the time a page takes to load directly correlates with bounce and conversion rates. In this tutorial we will take a look

Introduction The most common thing you learn in CSS Grid is usually related to the grid container and rather than the grid items. A generic grid definition applied to the grid container is enough for a basic layout structure. However, when you need more control over the contents of the grid, the grid container is

Talk about the latest cutting-edge web technologies, and you find some impressive names like React.js, Vue.js, Next.js, and so on. They have opened new gateways and approaches to building websites that can serve content to users quickly. One framework that can increase overall site speed and load times is Gatsby.js. Goals of a Fast Website

Introduction When fetching data in a JavaScript application, async-await allows us to use imperative synchronous programming for fetching data. This means that our code will imperatively describe how the program will function and will operate along a single thread of operations. React, on the other hand, is a library that build UIs declaratively. This is

The author selected the the Apache Software Foundation to receive a donation as part of the Write for DOnations program. Introduction In MySQL a trigger is a user-defined SQL command that is invoked automatically during an INSERT, DELETE, or UPDATE operation. The trigger code is associated with a table and is destroyed once a table

The author selected the Tech Education Fund to receive a donation as part of the Write for DOnations program. Introduction AdonisJs is a Node.js web framework written in plain JavaScript that runs on all major operating systems. It uses the popular MVC (Model – View – Controller) design pattern and offers a stable ecosystem for

This comic compares imperative and declarative Kubernetes management. If you would like to learn more about Kubernetes, please check our our Kubernetes Course for Full-Stack Developers.

The author selected the Diversity in Tech Fund to receive a donation as part of the Write for DOnations program. Introduction InSpec is an open-source auditing and automated testing framework used to describe and test for regulatory concerns, recommendations, or requirements. It is designed to be human-readable and platform-agnostic. Developers can work with InSpec locally

toLocaleString is a built-in JavaScript method used to convert the date and time to a string using the system locales. It can be used with the following JavaScript types : Dates/Time Numbers Objects Arrays toLocaleString with Dates and Time With dates/time objects, toLocaleString has a syntax like this and returns a string : dateObject.toLocaleString(locales, options)

Below is a brief overview on how to get started troubleshooting bugs in your Ionic projects. Introduction There are two main types of bugs that occur when developing in Ionic: Web bugs The first type are bugs that can be reproduced in the browser and are not related to the native functionality of the app.

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction Let’s Encrypt is a Certificate Authority (CA) that provides an easy way to obtain and install free TLS/SSL certificates, thereby enabling encrypted HTTPS on web servers. It simplifies the process by providing a

I’ve been working on a Flutter application for the better half of this year, and as we get closer to release, I realized I hadn’t set an app icon yet. I initially went ahead and set my icons with Xcode and Android Studio, but after finding the flutter_launcher_icons plugin – I’ll never need to do

Introduction Node.js is an open source Javascript runtime environment for easily building server-side and networking applications. The platform runs on Linux, OS X, FreeBSD, and Windows, and its applications are written in JavaScript. Node.js applications can be run at the command line but we will teach you how to run them as a service, so

The author selected the Open Internet/Free Speech Fund to receive a donation as part of the Write for DOnations program. Introduction Private networks generally provide internet access to the hosts using NAT (network address translation), sharing a single public IP address with all hosts inside the private network. In NAT systems, the hosts inside the

Introduction Apache Tomcat is a web server and servlet container that is used to serve Java applications. Tomcat is an open source implementation of the Java Servlet and JavaServer Pages technologies, released by the Apache Software Foundation. This tutorial covers the basic installation and some configuration of the latest release of Tomcat 9 on your

The scope is the execution context of a variable or function. It defines what data it has access to. This concept may seem pretty straightforward, but has some important subtleties. JavaScript has traditionally had two types of scope: global scope and local scope. The purpose of the scope is to provide access to all variables

The author selected the Open Internet/Free Speech fund to receive a donation as part of the Write for DOnations program. Introduction A large amount of data that is generated today is unstructured, which requires processing to generate insights. Some examples of unstructured data are news articles, posts on social media, and search history. The process

One of the most fundamental aspects of a mobile app is for the user to be able to move between different pages. Luckily for us, Flutter makes creating routes and moving between screens incredibly easy, especially when compared to many front-end solutions. Project File Setup For our example, we’re just going to have 4 screens,

While Flutter has an enormous amount of amazing packages for creating animation effects for your apps, there are also built-in methods for manually creating more fine-tuned animations. Prerequisites For our cross-screen animations I’ll be assuming that you already know how to create basic routes, just to keep things brief. You can review the docs here

Before getting into module augmentation, let’s look at some TypeScript merging principles which will become useful as we progress. In this post we talked about merging interfaces with interfaces. Additionally, we can merge interfaces with classes too. Let’s look at an example. class Food { cheese: string;}interface Food { bacon: string;}const food = new Food();food.bacon

This is the second post on declaration merging in TypeScript. In the previous post, we looked at what declaration merging is and started with interfaces. In this post, we will look at how to merge enums. For an introduction to Enums and why they are useful, you can read this post. Let’s get started: enum

Specificity in CSS refers to the how browsers determine the importance, relevance, and “seniority” of CSS styles. Here we’ll look at all the CSS styling types and use the company analogy to understand how competing styles get resolved. CSS Selector Overview There are multiple ways to select the elements you’re trying to style in CSS.

In this article, we’ll look at the new release of react-notifications-component (v2.0.6). It’s a React component that provides you with a fully-featured notification system that will save you the time effort of building one yourself. Let’s start by installing it, along with animate.css: npm install –save react-notifications-component animate.css We’re using animate.css for animating how the

Introduction Jupyter Notebook offers a command shell for interactive computing as a web application so that you can share and communicate with code. The tool can be used with several languages, including Python, Julia, R, Haskell, and Ruby. It is often used for working with data, statistical modeling, and machine learning. This tutorial will walk

In this article we’ll be exploring one of the best animation frameworks for React: React Spring. You’ll learn some of the basics behind changing you component styling into smooth, physics-based transitions. Prerequisites React Spring has both a hooks-based and a component-based API, we’ll be exclusively looking at using hooks with basic state for all our

The eval() function has been around for a long time in JavaScript! You likely don’t see it often anymore because it’s widely agreed that it’s harmful to use. Let’s take a brief look at it, and some of the dangers associated with using it. The keyword eval is an abbreviation for “evaluate.” The function essentially

The will-change CSS property is commonly misunderstood or not used correctly, in this short post I will demystify the property so you can make your CSS animations and transitions as performant as possible. What is will-change? In a nutshell, the will-change property is a way to tell the browser ahead of a time which properties

Over in the first part of this introduction to Electron.js, we just got Electron setup with our bundling scripts and a local window. With the foundations out of the way, we can get started with the more interesting functionality of our app. Passing Data Between Client and Server Since we’re not setup with a database

In our previous post on TypeScript Mixins, we talked briefly about declaration merging in TypeScript. In these series of posts, we are going to go a little deeper starting with interfaces with interface declaration merging. What is Declaration Merging? Declaration merging is when the TypeScript complier merges two or more types into one declaration provided

Introduction Apache’s mod_rewrite module lets you rewrite URLs in a cleaner fashion, translating human-readable paths into code-friendly query strings. It also lets you rewrite URLs based on conditions. An .htaccess file lets you create and apply rewrite rules without accessing server configuration files. By placing the .htaccess file in the root of your web site,

Google Fonts is a service provided for free by Google that allows access to thousands of fonts. All the available fonts are under Open Source licenses, meaning they’re free to use for both commercial and non-commercial projects. Getting started This article will go over using Google Fonts on a webpage. Below is what a boilerplate

There’s often a point when you’re building a website, especially a simple landing page, when you realize you’re going to have to introduce some JavaScript. CSS, however, can often do a lot more than we give it credit for. Here we’ll look at creating click handlers with only CSS! Let’s say we’re building an HTML

Introduction Quotas are used to limit the amount of disk space a user or group can use on a filesystem. Without such limits, a user could fill up the machine’s disk and cause problems for other users and services. In this tutorial we will install command line tools to create and inspect disk quotas, then

Introduction TLS, or transport layer security, and its predecessor SSL, which stands for secure sockets layer, are web protocols used to wrap normal traffic in a protected, encrypted wrapper. Using this technology, servers can send traffic safely between servers and clients without the possibility of messages being intercepted by outside parties. The certificate system also

I first discovered Airtable in late 2018, and was immediately blown away. For those not already familiar with it yet, Airtable is a cloud-based collaborative database-spreadsheet hybrid application. It offers a flexible and intuitive GUI, reasonable prices (along with a generous free tier), and a full REST API with excellent auto-generated documentation. It also works

In the frontend development community, we tend to use the word performance quite a lot. We all have the common goal of having a performant application. Brian Vaughan developed react-window with this in mind and he did a great job of giving us a powerful tool to achieve this goal. The Theory Behind react-window react-window

In this article we’ll be looking into using Stripe’s Charges API to make a basic donation app where we can create customers and submit payments. Prerequisites Understanding basic promises and how to set up an Express server are necessary. Installation We’re going to need quite a few things to get this set up. Body-parser will

Introduction Let’s Encrypt is a service that offers free SSL certificates through an automated API. The most popular Let’s Encrypt client is EFF’s Certbot client. Certbot offers a variety of ways to validate your domain, fetch certificates, and automatically configure Apache and Nginx. In this tutorial, we’ll discuss Certbot’s standalone mode and how to use

Introduction The Apache HTTP server is the most widely-used web server in the world. It provides many powerful features including dynamically loadable modules, robust media support, and extensive integration with other popular software. In this guide, we’ll explain how to install an Apache web server on your Debian 10 server. Prerequisites Before you begin this

Below you’ll find a quick demo on how to get GPS coordinates in your Ionic 4 project using Capacitor. If you have not heard of Capacitor, it’s the replacement for Cordova from the Ionic team. It focuses on providing native functionality and plugins for Progressive Web Apps (PWAs), iOS and Android. It’s the future of

In this article we’ll be looking at using the Mutation and Subscription types to manipulate and watch our data for changes, instead of just querying, in GraphQL. Feel free to discover more in the official docs. To keep things simple, we won’t be using any databases or HTTP requests, but knowing how to set up

Progressive Web Apps (PWAs) allow developers to deliver an app-like experience to the user. Paired with the top-notch performance of Gatsby.js, and you get a blazing fast website. The steps in this guide assume you have a working Gatsby project. So if you haven’t already, you can get started with Gatsby by following along the

If you’re already familiar with how arguments functions work in JavaScript, understanding props is a piece of cake! In a nutshell, props are used to pass data from a parent component to a child component in React and they are the main mechanism for component communication. So in essence, props are a major part of

Introduction TLS, or transport layer security, and its predecessor SSL, which stands for secure sockets layer, are web protocols used to wrap normal traffic in a protected, encrypted wrapper. Using this technology, servers can send traffic safely between the server and clients without the possibility of the messages being intercepted by outside parties. The certificate

Introduction Go, also known as golang, is a modern, open-source programming language developed by Google. Go tries to make software development safe, fast and approachable to help you build reliable and efficient software. This tutorial will guide you through downloading and installing Go from source, as well as compiling and executing a “Hello, World!” program

Introduction Composer is a popular dependency management tool for PHP, created mainly to facilitate installation and updates for project dependencies. It will check which other packages a specific project depends on and install them for you, using the appropriate versions according to the project requirements. Composer is also commonly used to bootstrap new projects based

Introduction FTP, short for File Transfer Protocol, is a network protocol that was once widely used for moving files between a client and server. It has since been replaced by faster, more secure, and more convenient ways of delivering files. Many casual internet users expect to download directly from their web browser with https, and

Introduction Node.js is an open-source JavaScript runtime environment for building server-side and networking applications. The platform runs on Linux, macOS, FreeBSD, and Windows. Though you can run Node.js applications at the command line, this tutorial will focus on running them as a service. This means that the applications will restart on reboot or failure and

The author selected the Open Internet/Free Speech Fund to receive a donation as part of the Write for DOnations program. Introduction The Apache HTTP web server has evolved through the years to work in different environments and solve different needs. One important problem Apache HTTP has to solve, like any web server, is how to

Introduction Let’s Encrypt is a Certificate Authority (CA) that provides a straightforward way to obtain and install free TLS/SSL certificates, enabling encrypted HTTPS on web servers. It simplifies the process by providing a software client, Certbot, that attempts to automate most (if not all) of the required steps. Currently, the entire process of obtaining and

preserveAspectRatio is the partner in crime of the SVG viewBox. If you do not understand the viewBox just yet, then go check out my other article here explaining it. preserveAspectRatio gives us the ability to tell our graphic how to scale when the aspect ratio of the viewBox and viewPort are different. By default our

Introduction Anaconda is an open-source package manager, environment manager, and distribution of the Python and R programming languages. Designed for data science and machine learning workflows, Anaconda is commonly used for large-scale data processing, scientific computing, and predictive analytics. Offering a collection of over 1,000 packages to support users working with data, Anaconda is available

Introduction Postfix is a mail transfer agent (MTA), an application used to send and receive email. In this tutorial, you will install and configure Postfix so that it can be used to send emails by local applications only — that is, those installed on the same server as Postfix. Why would you want to do

Introduction When you first create a new Debian 10 server, there are a few configuration steps that you should take early on as part of the basic setup. This will increase the security and usability of your server and will give you a solid foundation for subsequent actions. In this tutorial, we will learn how

Introduction SSH, or secure shell, is an encrypted protocol used to administer and communicate with servers. When working with a Debian server, chances are you will spend most of your time in a terminal session connected to your server through SSH. In this guide, we’ll focus on setting up SSH keys for a vanilla Debian

Introduction The Debian operating system’s most recent stable release, version 10 (Buster), was published on July 6, 2019, and will be supported until 2022. Long term support may be provided through 2024 as part of the Debian LTS Project. This guide is a brief overview of the new features and significant changes to Debian since

Learn about a React library called React Icons that provides thousands of free, Open Source icons that you can use in your next project. If you’re working on a React app that needs icons, check out react-icons! It includes 9 popular Open Source icon libraries, including Font Awesome and Material Design. To get started, install

All developers make mistakes and as a result bugs show up. We face bugs constantly and it’s essential for programmers to have good debugging skills. I’ll show you a few principles can make you more efficient in debugging. A Few Good Principles of Debugging You have to first understand what your code should be doing,

For me, personally, one of the most boring parts about starting a new web project is having to structure the initial markup. I’m usually ready to dive straight into planning out the logic, setting up a database, or even just adding some basic styling, yet there I am copy/pasting lorem ipsum text 50 freaking times.

The author selected the Free Software Foundation to receive a donation as part of the Write for DOnations program. Introduction OTRS, also known as Open source Ticket Request System, is a help desk and IT service management system. It provides a single point of contact for users, customers, IT personnel, IT services, and any external

The author selected the Open Internet/Free Speech Fund to receive a donation as part of the Write for DOnations program. Introduction Buildbot is a job scheduling system commonly used for the purpose of continuous integration (CI). CI is a software development practice that typically comprises automatically building and testing your software on a regular basis

Visual testing (sometimes called visual regression testing or UI testing) is the process of reviewing software for purely visual integrity. Unlike the tools you use to make sure your app is behaving as intended, visual testing is all about what your users actually see and interact with. It works by comparing snapshots of your UI

The author selected Girls Who Code to receive a donation as part of the Write for DOnations program. Introduction Docker is a containerization tool used to provide applications with a filesystem holding everything they need to run, ensuring that the software will have a consistent run-time environment and will behave the same way regardless of

In this article, learn how to use CSS float positioning, as well as some of the pitfalls when using it. Newbies to CSS usually have a difficult time grasping how float positioning works. This is probably because people tend to overuse it, or many times they’re using a CSS framework that uses it waaaay too

Introduction Go, also known as golang, is a modern, open-source programming language developed by Google. Increasingly popular for many applications, Go takes a minimalist approach to development, helping you build reliable and efficient software. This tutorial will guide you through downloading and installing Go, as well as compiling and executing a basic “Hello, World!” program

The author selected the Open Internet/Free Speech Fund to receive a donation as part of the Write for DOnations program. Introduction In complex service-oriented architectures (SOA), programs often need to call multiple services to run through a given workflow. This is fine once everything is in place, but if the code you are working on

Introduction Let’s Encrypt is a service offering free SSL certificates through an automated API. The most popular Let’s Encrypt client is EFF’s Certbot. Certbot offers a variety of ways to validate your domain, fetch certificates, and automatically configure Apache and Nginx. In this tutorial, we’ll discuss Certbot’s standalone mode and how to use it to

In Svelte components can be composed together using slots. Composition means allowing your components to contain other components or HTML elements. Slots are made possible in Svelte by using the slot component inside components that can accept components or markup within. It’s something that we’re already used to do naturally with HTML elements. Let’s demonstrate

Introduction MQTT is a machine-to-machine messaging protocol, designed to provide lightweight publish/subscribe communication to “Internet of Things” devices. It is commonly used for geo-tracking fleets of vehicles, home automation, environmental sensor networks, and utility-scale data collection. Mosquitto is a popular MQTT server (or broker, in MQTT parlance) that has great community support and is easy

Introduction One of the easiest way of guarding against out-of-memory errors in applications is to add some swap space to your server. In this guide, we will cover how to add a swap file to a Debian 9 server. Warning: Although swap is generally recommended for systems using traditional spinning hard drives, using swap with

The author selected the Wikimedia Foundation to receive a donation as part of the Write for DOnations program. Introduction Cloudron is a platform that streamlines the installation and management of apps on your server, like WordPress, Rocket.Chat, Nextcloud, GitLab, OpenVPN, and more. A key benefit of using Cloudron is that it performs end-to-end deployment of

When designing software with a user interface, it is important to structure the code in a way that makes it easy to extend and maintain. Over time, there have been a few approaches in separating out responsibilities of the different components of an application. Although there is plenty of literature on these design patterns around,

Angular 8 has arrived and with it a bunch of workflow and performance improvements. Like we did for the previous few releases, let’s go over what’s new with Angular 8 as well as how to go about upgrading your Angular 7 apps over to Angular 8. Angular 8 Release Highlights I’d say that the number

Props, popular with other frameworks such as React and Vue.js, are a very efficient way to enable component communication. Props are used in Svelte as you’d expect. They are passed top-down from parent components to children and are used to specify data that the component can consume to inform what it renders in the DOM.

Introduction Let’s Encrypt is a Certificate Authority (CA) that provides free certificates for Transport Layer Security (TLS) encryption, thereby enabling encrypted HTTPS on web servers. It simplifies the process of creation, validation, signing, installation, and renewal of certificates by providing a software client that automates most of the steps—Certbot. In this tutorial, you will use

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction Unison is an open-source file synchronization tool. It is very efficient at backing up large corpuses of data where only a few files have been added or updated. This situation occurs in, for

In this article, learn how to incorporate sound effects in your React apps using a small library called uifx. Sound effects aren’t used often for apps. You usually just see them on Big Tech’s apps like: The iOS keyboard makes a wooden tap sound Twitter iOS app makes a “boop” noise when you pull-to-refresh “Hey

Huzzah! create-react-app v3.0.0 was just announced by the React Team! In this article, we’ll cover the most important features and go over some juicy code snippets. Instead of attempting to provide a comprehensive list of the changes in v3.0.0, I’ve grouped by tools and libraries (TypeScript, Jest, etc) so that you can cherry-pick what you

The author selected The Computer History Museum to receive a donation as part of the Write for DOnations program. Introduction Twitter bots are a powerful way of managing your social media as well as extracting information from the microblogging network. By leveraging Twitter’s versatile APIs, a bot can do a lot of things: tweet, retweet,

The author selected Mozilla Foundation to receive a donation as part of the Write for DOnations program. Introduction Reactive Programming is a paradigm concerned with asynchronous data streams, in which the programming model considers everything to be a stream of data spread over time. This includes keystrokes, HTTP requests, files to be printed, and even

The author selected the Open Source Initiative to receive a donation as part of the Write for DOnations program. Introduction Zabbix is open-source monitoring software for networks and applications. It offers real-time monitoring of thousands of metrics collected from servers, virtual machines, network devices, and web applications. These metrics can help you determine the current

Introduction Designed for data science and machine learning workflows, Anaconda is an open-source package manager, environment manager, and distribution of the Python and R programming languages. It is commonly used for large-scale data processing, scientific computing, and predictive analytics. Offering a collection of over 1,000 data science packages, Anaconda is available in both free and

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction ClickHouse is an open-source, column-oriented analytics database created by Yandex for OLAP and big data use cases. ClickHouse’s support for real-time query processing makes it suitable for applications that require sub-second analytical results.

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction Unison is an open-source file synchronization tool. It is very efficient at backing up large corpuses of data where only a few files have been added or updated. This situation occurs in, for

Angular allows us to build performant web applications that can be deployed to mobile, web and desktop. Firebase Hosting is a popular service that is easy to use with a CLI tool. In this article, we’ll be using Travis CI to automate this deployment. New Angular Application Create a new Angular project with the Angular

The author selected Girls Who Code to receive a donation as part of the Write for DOnations program. Introduction Computer vision is a subfield of computer science that aims to extract a higher-order understanding from images and videos. This field includes tasks such as object detection, image restoration (matrix completion), and optical flow. Computer vision

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction InSpec is an open-source, automated testing framework for testing and auditing your system to ensure the compliance of integration, security, and other policy requirements. Developers can test the actual state of their infrastructure

Introduction Despite being a commercial failure after its first publication, Herman Melville’s allegorical adventure novel Moby-Dick; or, The Whale is today one of the most popular and influential novels in the American canon. Artists as diverse as William Faulkner, Ralph Ellison, and Bob Dylan have acknowledged the novel’s impact on their work, and one can

Cables. Who needs them? Not you, because you’re using Ionic DevApp! This is an awesome application available on the iOS and Android stores that allow you to test your Ionic applications on the device, quickly and easily. Better yet – all changes that you make from within your editor are shown inside of the application

The author selected Tech Education Fund to receive a donation as part of the Write for DOnations program. Introduction Backing up your Apache Kafka data is an important practice that will help you recover from unintended data loss or bad data added to the cluster due to user error. Data dumps of cluster and topic

Navigating between pages is a core feature of any mobile application. Let’s look at how we can achieve this with React, React Router and Ionic 4. For this article, I’m going to assume that you have a React and Ionic 4 application already up and running. If you haven’t done this yet – visit my

Hyperapp is a very small micro-framework used to build declarative web applications. It’s only 1kB in size and the API is similar to React’s, perfect, right?! We’ll build a small counter app to demonstrate how Hyperapp works. New Hyper project To get started, we can create a new Node application and install hyperapp. We’ll then

The Router module is one of the most important in the Angular library. Paired with Ionic 4, you can be unstoppable. Here’s the rundown: Background One of Ionic 4’s key features is its capability to use Angular routing. The Angular router implements a path/component lookup. In other words, Angular routing works like URLs on a

The author selected the Tech Education Fund to receive a donation as part of the Write for DOnations program. Introduction Backing up your Apache Kafka data is an important practice that will help you recover from unintended data loss or bad data added to the cluster due to user error. Data dumps of cluster and

The author selected Code.org to receive a donation as part of the Write for DOnations program. Introduction In a production environment, Docker makes it easy to create, deploy, and run applications inside of containers. Containers let developers gather applications and all their core necessities and dependencies into a single package that you can turn into

Introduction Machine learning is a research field in computer science, artificial intelligence, and statistics. The focus of machine learning is to train algorithms to learn patterns and make predictions from data. Machine learning is especially valuable because it lets us use computers to automate decision-making processes. You’ll find machine learning applications everywhere. Netflix and Amazon

The release of KV Storage is a big deal for the web platform. It’s part of the Standard Library Proposal which could see a more extensive standard library being introduced for JavaScript. Before jumping in to what kv-storage is, let’s first discuss how we can store data within the browser. If I wanted to store

Introduction TensorFlow is open-source machine learning software used to train neural networks.TensorFlow’s neural networks are expressed in the form of stateful dataflow graphs. Each node in the graph represents the operations performed by neural networks on multi-dimensional arrays. These multi-dimensional arrays are commonly known as “tensors,” hence the name TensorFlow. TensorFlow is a deep learning

Introduction Many data analysis, big data, and machine learning projects require scraping websites to gather the data that you’ll be working with. The Python programming language is widely used in the data science community, and therefore has an ecosystem of modules and tools that you can use in your own projects. In this tutorial we

Introduction An API, or Application Program Interface, enables developers to integrate one app with another. They expose some of a program’s inner workings in a limited way. You can use APIs to get information from other programs or to automate things you normally do in your web browser. Sometimes you can use APIs to do

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction ClickHouse is an open-source, column-oriented analytics database created by Yandex for OLAP and big data use cases. ClickHouse’s support for real-time query processing makes it suitable for applications that require sub-second analytical results.

Vue Styleguidist is a Node package to automatically create documentation for your Vue Components. Alex Jover Morales presented it last year on Alligator.io. Since last February, vue-styleguidist has evolved. It’s time for a refresher. The new documentation website powered by VuePress will help you start documenting. Vue-styleguidist 3 brings a significant performance boost. vue-docgen-api went

The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. Introduction ClickHouse is an open-source, column-oriented analytics database created by Yandex for OLAP and big data use cases. ClickHouse’s support for real-time query processing makes it suitable for applications that require sub-second analytical results.

Maybe not the most popular opinion, but I absolutely love monorepos. When you’re starting a brand new project, it just makes sense to have a single repo and growing things from there. Unfortunately, as projects grow, things can get unwieldy. Next thing you know, back and front end code are sharing dependencies and your package.json

React 360 (or React VR) is a library used to create virtual reality experiences with React and uses Three.js for rendering. As it is a React project, the API should be familiar to those that already know React. Usage of React 360 is similar to that of React Native, it is a library that uses

Introduction Quotas are used to limit the amount of disk space a user or group can use on a filesystem. Without such limits, a user could fill up the machine’s disk and cause problems for other users and services. In this tutorial we will install command line tools to create and inspect disk quotas, then

This article aims to show how selections work within D3. We’ll start with a basic project that includes d3.js as a script with no build system: !DOCTYPE htmlhtml head titleD3: Selections/title /head body div pHi! My name is Paul and here’s some facts about me./p ul liI’m a powerlifter/li liI’m studying MSc Data Science/li liI

Progressive Web Applications, or PWAs, allow web developers to create web apps that can behave more like native applications. A huge selling point of PWAs is that they can work with poor network connectivity, or even with no connectivity at all! They accomplish this by caching the web app’s assets and — when possible —

The author selected the Electronic Frontier Foundation to receive a donation as part of the Write for DOnations program. Introduction Two-factor authentication (2FA) is an authentication method that requires entering more than one piece of information to successfully log in to an account or device. In addition to entering a username and password combination, 2FA

Axios is a powerful HTTP client that allows to easily implement Ajax requests in a JavaScript app. We’ve covered the basics of using Axios with React here, so you can read that first if Axios or Axios + React is all new to you. In this tutorial we’ll be building a live search feature inside

The author selected NPower to receive a donation as part of the Write for DOnations program. Introduction Angular is a front-end web framework built by Google. It allows developers to build single-page applications modeled around a model-view-controller (MVC) or model-view-viewmodel (MVVM) software architectural pattern. This architecture divides applications into different, but connected parts allowing for

The author selected Software in the Public Interest Inc to receive a donation as part of the Write for DOnations program. Introduction Nest.js is a scalable, server-side JavaScript framework built with TypeScript that still preserves compatibility with JavaScript, which makes it an effective tool for building efficient and reliable back-end applications. It has a modular

Capacitor, a project built by the team behind Ionic, is a great way to take your JavaScript web applications and get them running on iOS, Android, desktop (via Electron) or the web platform. It allows you to access the native device’s SDKs and aims to be a replacement for Cordova. I’ll be assuming that we

As front-end applications become increasingly complex, with the potential of multiple actors affecting the global state of the application in different ways, it becomes easy to lose control of what’s going on with your state. If you’ve never had to worry about managing global state in your JavaScript application, congratulations! You are one of the

Introduction A service mesh is an infrastructure layer that allows you to manage communication between your application’s microservices. As more developers work with microservices, service meshes have evolved to make that work easier and more effective by consolidating common management and administrative tasks in a distributed setup. Taking a microservice approach to application architecture involves

The author selected Electronic Frontier Foundation Inc to receive a donation as part of the Write for DOnations program. Introduction Seafile is an open-source, self-hosted, file synchronization and sharing platform. Users can store and optionally encrypt data on their own servers with storage space as the only limitation. With Seafile you can share files and

The author selected Girls Who Code to receive a donation as part of the Write for DOnations program. Introduction Reinforcement learning is a subfield within control theory, which concerns controlling systems that change over time and broadly includes applications such as self-driving cars, robotics, and bots for games. Throughout this guide, you will use reinforcement

Introduction Docker is a great tool for automating the deployment of Linux applications inside software containers, but to really take full advantage of its potential it’s best if each component of your application runs in its own container. For complex applications with a lot of components, orchestrating all the containers to start up and shut

The constructor is a method that’s automatically called during the creation of an object from a class. It can handle your initial setup stuff like defaulting some properties of the object, or sanity checking the arguments that were passed in. Simply put, the constructor aids in constructing things. In React, the constructor is no different.

Organizing code is going to save us from a lot of pain. Using the features of Object Oriented programming, we can employ certain design patterns to achieve better readability, reduce redundancy and create abstractions, if needed. One such pattern is the factory pattern. The factory pattern is a type of Object Oriented pattern which follows

The author selected the Open Internet/Free Speech to receive a donation as part of the Write for DOnations program. Introduction Kubernetes is an open source container orchestration system. It allows you to create, update, and scale containers without worrying about downtime. To run a PHP application, Nginx acts as a proxy to PHP-FPM. Containerizing this

The author selected the Mozilla Foundation to receive a donation as part of the Write for DOnations program. Introduction YunoHost is an open-source platform that facilitates the seamless installation and configuration of self-hosted web applications, including webmail clients, password managers, and even WordPress sites. Self-hosting webmail and other applications provides privacy and control over your

Considering the fact that almost everything in JavaScript is an object, object oriented JavaScript code is very different from other object-capable languages. The JS object system is more of a prototype-based object system instead. Coming from a C++ background, I was aware of the Object Oriented programming paradigm and had a very rigid idea of

The author selected Girls Who Code to receive a donation as part of the Write for DOnations program. Introduction Docker can be an efficient way to run web applications in production, but you may want to run multiple applications on the same Docker host. In this situation, you’ll need to set up a reverse proxy

Storybook allows you to develop UI components in isolation, which can improve component reuse, testability, and development speed. Along with these developer experience (DX) benefits, Storybook works nicely with traditional component development and doesn’t require changes to core functionality to display, test, and document your component library. It can also provide further extension through “addons”

The author selected the Apache Software Foundation to receive a donation as part of the Write for DOnations program. Introduction Docker Registry is an application that manages storing and delivering Docker container images. Registries centralize container images and reduce build times for developers. Docker images guarantee the same runtime environment through virtualization, but building an

Introduction Memory object caching systems like Memcached can optimize back-end database performance by temporarily storing information in memory, retaining frequently or recently requested records. In this way, they reduce the number of direct requests to your databases. Because systems like Memcached can contribute to denial of service attacks if improperly configured, it is important to

The author selected Code Org to receive a donation as part of the Write for DOnations program. Introduction Rancher is a popular open-source container management platform. Released in early 2018, Rancher 2.X works on Kubernetes and has incorporated new tools such as multi-cluster management and built-in CI pipelines. In addition to the enhanced security, scalability,

The author selected Wikimedia Foundation Inc. to receive a donation as part of the Write for DOnations program. Introduction Apache ZooKeeper is open-source software that enables resilient and highly reliable distributed coordination. It is commonly used in distributed systems to manage configuration information, naming services, distributed synchronization, quorum, and state. In addition, distributed systems rely

Keys are an important aspect to rendering collections. React uses component keys to determine which of the components in a collection needs to be re-rendered instead of just re-rendering the entire set of components every time anything changes. This simple but powerful bit of functionality helps keep your React app snappy and that’s a good

The author selected the Wikimedia Foundation to receive a donation as part of the Write for DOnations program. Introduction Over the last few years, open-source web frameworks have greatly simplified the process of coding an application. React, for example, has only added to the popularity of JavaScript by making the language more accessible to new

The author selected Software in the Public Interest to receive a donation as part of the Write for DOnations program. Introduction The Elastic Stack — formerly known as the ELK Stack — is a collection of open-source software produced by Elastic which allows you to search, analyze, and visualize logs generated from any source in

The importance of testing Vue.js applications shouldn’t be understated and Jest makes this easier than ever. As we’re inside of the Vue.js environment, we’ll also be using vue-test-utils to make it easy when interfacing with native Vue elements. Project Setup Setting up our testing environment is easy. In previous versions of the Vue.js CLI, we

Function components are great, but they are limited to do exactly what they are told by way of properties. The moment you need them to be mindful of their state, you are forced to rewrite them as class components. Fortunately, a lot of class component-only features are making their way to function components. One such

Introduction As your application or website grows, there may come a point where you’ve outgrown your current server setup. If you are hosting your web server and database backend on the same machine, it may be a good idea to separate these two functions so that each can operate on its own hardware and share

In order to understand the newer destructuring syntax introduced in ES6, let’s cover the “old” way. I’ll mention this a couple times throughout, but these are optional syntaxes that MAY help. There are still some use cases that are cleaner with the original methods, such as property accessors, and that is perfectly valid. // some

Introduction The Elastic Stack — formerly known as the ELK Stack — is a collection of open-source software produced by Elastic which allows you to search, analyze, and visualize logs generated from any source in any format, a practice known as centralized logging. Centralized logging can be very useful when attempting to identify problems with

Writing tests can be a very important part of your development cycle. Most code is easy to test, data goes in, write tests to make sure the right data comes out. Things start to get difficult when you introduce network requests. It’s easy enough to stand up an API server and writing integration tests, but

Introduction Nginx is one of the most popular web servers in the world, known for its frequent use as a load balancer and reverse proxy. It’s more resource-friendly than Apache, and many of the largest and most highly trafficked sites on the internet depend on Nginx to serve their content. In this guide, we will

As you’re working with React.js or React Native, you’ll quickly notice the ✨magic✨ and flexibility that comes with components. Components save us a great deal of time by breaking down the user interface into reusable code while the component architecture makes our code easier to read and understand. Taking Component Organization to the Next Level

It’s not often that you write a web app that doesn’t contain at least one form. More often than naught, your entire app is just a series of forms. Each of these forms requires state management, event handlers, and, oftentimes, some sort of client-side data validation. Formik aims to do all of that in a

Introduction DigitalOcean’s Custom Images feature allows you to bring your virtual disk images from an on-premise environment or another cloud platform to DigitalOcean and use them to start DigitalOcean Droplets. As described in the Custom Images documentation, the following image types are supported natively by the Custom Images upload tool: Raw (.img) qcow2 VHDX VDI

Introduction The “LAMP” stack of software, consisting of the Linux operating system, Apache web server, MySQL database, and PHP scripting language, is a great foundation for web or application development. Installed together, this software stack enables your server to host dynamic websites and web applications. In this tutorial, we’ll install a LAMP stack on a

The author selected Software in the Public Interest Inc to receive a donation as part of the Write for DOnations program. Introduction Symfony is an open-source PHP framework with an elegant structure and a reputation for being a suitable framework to kick-start any project irrespective of its size. As a set of reusable components, its

Introduction Databases are a key component of many websites and applications, and are at the core of how data is stored and exchanged across the internet. One of the most important aspects of database management is the practice of retrieving data from a database, whether it’s on an ad hoc basis or part of a

Introduction Databases are a key component of many websites and applications, and are at the core of how data is stored and exchanged across the internet. One of the most important aspects of database management is the practice of retrieving data from a database, whether it’s on an ad hoc basis or part of a

You start working on a new project right after you finish reading this post. It’s not outlandish – something not too far off from a previous project you’ve done. After 20-or-so minutes of getting the project base ready (so that you can begin the real project), you get hit with an error. It doesn’t look

Introduction Docker Machine is a tool that makes it easy to provision and manage multiple Docker hosts remotely from your personal computer. Such servers are commonly referred to as Dockerized hosts and are used to run Docker containers. While Docker Machine can be installed on a local or a remote system, the most common approach

Introduction Implementing a CDN, or Content Delivery Network, to deliver your WordPress site’s static assets can greatly decrease your servers’ bandwidth usage as well as speed up page load times for geographically dispersed users. WordPress static assets include images, CSS stylesheets, and JavaScript files. Leveraging a system of edge servers distributed worldwide, a CDN caches

GraphQL schemas for a service are now most often specified using what’s known as the GraphQL SDL (schema definition language), also sometimes referred to as just GraphQL schema language. It’s a language with a very simple syntax that allows to define a schema very succinctly. Once you have a gasp at the different syntax elements

SQL Cheat Sheet Introduction SQL databases come installed with all the commands you need to add, modify, delete, and query your data. This cheat sheet-style guide provides a quick reference to some of the most commonly-used SQL commands. How to Use This Guide: This guide is in cheat sheet format with self-contained command-line snippets Jump

Shards Vue is a beautiful and modern Vue.js UI toolkit packed with dozens of custom pre-built components that you can use to kick-start your next app. The library was built from scratch with the goals of having a very small footprint and providing powerful components that are easy to use. The library is based on

In this article I’ll bring you up to speed on Reakit, a toolkit for building React UIs. Together we’ll build a customer information form using Reakit components. If you’re looking to understand how to start creating components with it in a short amount of time, read on! What We’ll Be Building Reakit offers a library

The author selected the Diversity in Tech Fund to receive a donation as part of the Write for DOnations program. Introduction Serverless architecture hides server instances from the developer and usually exposes an API that allows developers to run their applications in the cloud. This approach helps developers deploy applications quickly, as they can leave

Download the Kubernetes White Paper Running Cloud Native Applications on DigitalOcean Kubernetes (PDF) Abstract The Running Cloud Native Applications on DigitalOcean Kubernetes White Paper brings readers through a variety of cloud native topics, introducing them to how they may leverage Kubernetes in order to manage and scale their applications. This white paper provides further insight

Having a ton of data is a great thing. You can use it to identify usage patterns and trends or apply it towards predictive failure analysis for your fleet of servers. Sadly, a lot of the time data is meticulously collected and presented in a stale old table. Fortunately, with Victory (by Formidable) you can

Introduction R is an open-source programming language that specializes in statistical computing and graphics. Supported by the R Foundation for Statistical Computing, it is widely used for developing statistical software and performing data analysis. An increasingly popular and extensible language with an active community, R offers many user-generated packages for specific areas of study, which

Introduction Webmin is a modern web control panel for any Linux machine that allows you to administer your server through a simple interface. With Webmin, you can change settings for common packages on the fly. In this tutorial, you’ll install and configure Webmin on your server and secure access to the interface with a valid

Introduction Software version control systems enable you to keep track of your software at the source level. With versioning tools, you can track changes, revert to previous stages, and branch to create alternate versions of files and directories. Git is one of the most popular version control systems currently available. Many projects’ files are maintained

Introduction Jupyter Notebook offers a command shell for interactive computing as a web application. The tool can be used with several languages, including Python, Julia, R, Haskell, and Ruby. It is often used for working with data, statistical modeling, and machine learning. This tutorial will walk you through setting up Jupyter Notebook to run from

Introduction Want to access the Internet safely and securely from your smartphone or laptop when connected to an untrusted network such as the WiFi of a hotel or coffee shop? A Virtual Private Network (VPN) allows you to traverse untrusted networks privately and securely as if you were on a private network. The traffic emerges

Introduction Nextcloud, a fork of ownCloud, is a file sharing server that permits you to store your personal content, like documents and pictures, in a centralized location, much like Dropbox. The difference with Nextcloud is that all of its features are open-source. It also returns the control and security of your sensitive data back to

A previous version of this tutorial was written by Justin Ellingwood Introduction TLS, or transport layer security, and its predecessor SSL, which stands for secure sockets layer, are web protocols used to wrap normal traffic in a protected, encrypted wrapper. Using this technology, servers can send traffic safely between the server and clients without the

Introduction Postfix is a mail transfer agent (MTA), an application used to send and receive email. In this tutorial, you will install and configure Postfix so that it can be used to send emails by local applications only — that is, those installed on the same server as Postfix. Why would you want to do

Introduction Hadoop is a Java-based programming framework that supports the processing and storage of extremely large datasets on a cluster of inexpensive machines. It was the first major open source project in the big data playing field and is sponsored by the Apache Software Foundation. Hadoop is comprised of four main layers: Hadoop Common is

Introduction Apache Tomcat is a web server and servlet container that is used to serve Java applications. Tomcat is an open source implementation of the Java Servlet and JavaServer Pages technologies, released by the Apache Software Foundation. This tutorial covers the basic installation and some configuration of the latest release of Tomcat 9 on your

Introduction While many users need the functionality of a database management system like MariaDB, they may not feel comfortable interacting with the system solely from the MariaDB prompt. phpMyAdmin was created so that users can interact with MariaDB through a web interface. In this guide, we’ll discuss how to install and secure phpMyAdmin so that

Introduction Let’s Encrypt is a Certificate Authority (CA) that provides an easy way to obtain and install free TLS/SSL certificates, thereby enabling encrypted HTTPS on web servers. It simplifies the process by providing a software client, Certbot, that attempts to automate most (if not all) of the required steps. Currently, the entire process of obtaining

Introduction Redis is an in-memory key-value store known for its flexibility, performance, and wide language support. This tutorial demonstrates how to install, configure, and secure Redis on a Debian 9 server. Prerequisites To complete this guide, you will need access to a Debian 9 server that has a non-root user with sudo privileges and a

Introduction The mdadm utility can be used to create and manage storage arrays using Linux’s software RAID capabilities. Administrators have great flexibility in coordinating their individual storage devices and creating logical storage devices that have greater performance or redundancy characteristics. In this guide, we will go over a number of different RAID configurations that can

Introduction The Apache HTTP server is the most widely-used web server in the world. It provides many powerful features including dynamically loadable modules, robust media support, and extensive integration with other popular software. In this guide, we’ll explain how to install an Apache web server on your Debian 9 server. Prerequisites Before you begin this

Introduction MongoDB is a free and open-source NoSQL document database used commonly in modern web applications. In this tutorial you will install MongoDB, manage its service, and optionally enable remote access. Prerequisites To follow this tutorial, you will need one Debian 9 server set up by following this initial server setup tutorial, including a sudo-enabled

Introduction Let’s Encrypt is a Certificate Authority (CA) that provides an easy way to obtain and install free TLS/SSL certificates, enabling encrypted HTTPS on web servers. It simplifies the process by providing a software client, Certbot, that attempts to automate most (if not all) of the required steps. Currently, the entire process of obtaining and

Introduction Virtual Network Computing, or VNC, is a connection system that allows you to use your keyboard and mouse to interact with a graphical desktop environment on a remote server. It makes managing files, software, and settings on a remote server easier for users who are not yet comfortable with the command line. In this

Introduction SFTP stands for SSH File Transfer Protocol. As its name suggests, it’s a secure way to transfer files between machines using an encrypted SSH connection. Despite the name, it’s a completely different protocol than FTP (File Transfer Protocol), though it’s widely supported by modern FTP clients. SFTP is available by default with no additional

Introduction Databases grow over time, sometimes outgrowing the space on their original file system. When they’re located on the same partition as the rest of the operating system, this can also potentially lead to I/O contention. RAID, network block storage, and other devices can offer redundancy and improve scalability, along with other desirable features. Whether

Introduction MQTT is a machine-to-machine messaging protocol, designed to provide lightweight publish/subscribe communication to “Internet of Things” devices. It is commonly used for geo-tracking fleets of vehicles, home automation, environmental sensor networks, and utility-scale data collection. Mosquitto is a popular MQTT server (or broker, in MQTT parlance) that has great community support and is easy

Introduction Go is a modern programming language developed at Google. It is increasingly popular for many applications and at many companies, and offers a robust set of libraries. This tutorial will walk you through downloading and installing the latest version of Go (Go 1.10 at the time of this article’s publication), as well as building

Introduction MySQL is a prominent open source database management system used to store and retrieve data for a wide variety of popular applications. MySQL is the M in the LAMP stack, a commonly used set of open source software that also includes Linux, the Apache web server, and the PHP programming language. In order to

Introduction On Ubuntu, the Nginx web server stores its documents in /var/www/html, which is typically located on the root filesystem with rest of the operating system. Sometimes, though, it’s helpful to move the document root to another location, such as a separate mounted filesystem. For example, if you serve multiple websites from the same Nginx

Introduction Version control systems help you share and collaborate on software development projects. Git is one of the most popular version control systems currently available. This tutorial will walk you through installing and configuring Git on an Ubuntu 18.04 server. For a more detailed version of this tutorial, with better explanations of each step, please

Introduction Let’s Encrypt is a service offering free SSL certificates through an automated API. The most popular Let’s Encrypt client is EFF’s Certbot. Certbot offers a variety of ways to validate your domain, fetch certificates, and automatically configure Apache and Nginx. In this tutorial, we’ll discuss Certbot’s standalone mode and how to use it to

Introduction WordPress is the most popular CMS (content management system) on the internet. It allows you to easily set up flexible blogs and websites on top of a MySQL backend with PHP processing. WordPress has seen incredible adoption and is a great choice for getting a website up and running quickly. After setup, almost all

Introduction Apache Tomcat is a web server and servlet container that is used to serve Java applications. Tomcat is an open source implementation of the Java Servlet and JavaServer Pages technologies, released by the Apache Software Foundation. This tutorial covers the basic installation and some configuration of the latest release of Tomcat 8 on your

Introduction ownCloud is an open-source file sharing server and collaboration platform that can store your personal content, like documents and pictures, in a centralized location. This allows you to take control of your content and security by not relying on third-party content hosting services like Dropbox. In this tutorial, we will install and configure an

Introduction Nextcloud, a fork of ownCloud, is a file sharing server that permits you to store your personal content, like documents and pictures, in a centralized location, much like Dropbox. The difference with Nextcloud is that all of its features are open-source. It also returns the control and security of your sensitive data back to

A previous version of this tutorial was written by Justin Ellingwood Introduction One of the easiest way of guarding against out-of-memory errors in applications is to add some swap space to your server. In this guide, we will cover how to add a swap file to an Ubuntu 18.04 server. What is Swap? Swap is

Introduction Let’s Encrypt is a Certificate Authority (CA) that provides an easy way to obtain and install free TLS/SSL certificates, thereby enabling encrypted HTTPS on web servers. It simplifies the process by providing a software client, Certbot, that automates most of the steps.In this tutorial, we will show you how to use Certbot to obtain

React v16.3 introduces some interesting new features, such as the getDerivedStateFromProps method. In this post we’ll explore how to use it. In React v16.3, the getDerivedStateFromProps static lifecycle method was introduced as a replacement for componentWillReceiveProps. It’s important to move your components to this new method, as componentWillReceiveProps will soon be deprecated in an upcoming

Introduction Redis is an in-memory key-value store known for its flexibility, performance, and broad language support. It is commonly used as a database, cache, and message broker, and supports a wide range of data structures. This tutorial demonstrates how to install and configure Redis from source on an Ubuntu 18.04 server. Please note that Redis

Introduction Redis is an in-memory, NoSQL, key-value cache and store that can also be persisted to disk. It was designed for use by trusted clients in a trusted environment, with no robust security features of its own. To underscore that point, here’s a quote from the official Redis website: Redis is designed to be accessed

One thing that surprised me at first with React is how everything is a component. That may sound simple on the surface, but for the functional stuff (say form management, i18n (internationalization), routing, state…) it just doesn’t feel very natural to me and adds component layers for non-visual functional-only components. Usually other UI libs/frameworks have

Introduction GitLab is an open-source tool used by software teams to manage their complete development and delivery lifecycle. GitLab provides a broad set of functionality: issue tracking, git repositories, continuous integration, container registry, deployment, and monitoring. These features are all built from the ground up as a single application. You can host GitLab on your

Material Design is Google’s design language for the web centered around cards, grid-based layouts, and responsive animations. With Material-UI, a compact, customizable, and beautiful collection of components and utilities for React, putting the Material Design spec to use in your React app is a breeze. This post will cover the setup, usage, and theming of

Introduction Using Docker to containerize your applications and services can give you some security benefits out of the box, but a default Docker installation still has room for some security-related configuration improvements. The Center for Internet Security, a non-profit whose mission is to promote internet security best-practices, created a step-by-step checklist for securing Docker. Subsequently,

Electron is a popular framework that makes it easy to build desktop apps for macOS, Linux, or Windows using familiar web technologies (HTML, JavaScript, and CSS). Some very popular desktop apps, such as Visual Studio Code and Slack, are built using Electron. Behind the scenes, Electron uses Chromium for UI rendering and Node.js for filesystem

Redux is a separate entity from React and can be used with any JavaScript front-end framework or with vanilla JavaScript. Still though, it’s undeniable that React and Redux are very commonly used together, and for this the React Redux library provides simple bindings that make it really easy to connect the two. The API for

In Resetting Redux State we’ve seen a way to reuse reducer logic to reset the state by creating a root reducer. But that’s not the only way to reuse reducer logic, and higher-order reducers come into the scene to help us with reusability and reducing code duplication. Higher-order reducers, unlike the root reducer approach, allow

The author selected the Electronic Frontier Foundation to receive a $300 donation as part of the Write for DOnations program. Introduction You’ve probably downloaded some open-source software, such as a Linux distribution ISO, and next to the download link was a link to download a checksum of the file. Have you ever wondered what that

Media queries give us a very powerful way to adjust our styles according to factors like the type of device used, the viewport size, the screen’s pixel density, or even the device orientation. As media queries have been around for quite a while, you may already be familiar with the basic syntax and usage. This

Introduction FileZilla Pro is a file transfer solution that works with FTP, SFTP, FTPS, and WebDAV protocols. In 2001, the original FileZilla project brought an open-source, cross-platform file access and transfer application to users. Today, FileZilla Pro offers support for a growing number of network and cloud protocols. DigitalOcean Spaces is an object storage solution

This is part 2 of a 4-part series on testing React / Redux apps using both Jest and Enzyme for a robust testing solution. In this part we’ll cover some simple examples on how to test React components. The series Part 1: Installation Setup Part 2: Testing React Components (this post) Part 3: Testing Redux

Introduction Go, also referred to as golang, is a modern, open-source programming language developed by Google. Increasingly popular for many applications, Go takes a minimalist approach to development, helping you build reliable and efficient software. This tutorial will guide you through downloading and installing Go, as well as compiling and executing a basic “Hello, World!”

Most real world apps need authentication and authorization. While authentication identifies some entity as a valid user, authorization defines the actions that the user is allowed to perform, based on his/her roles and rights. We don’t usually need any special module or library to handle authorization and in most cases, a few utility functions are

Introduction Regular database backups are a crucial step in guarding against unintended data loss events. Designing an effective backup and recovery strategy often involves trading off performance impact, implementation costs, and data storage costs with recovery speed, data integrity, and backup coverage. The optimal solution will depend on your recovery point and time objectives and

When it comes to charting on the web, there are two main heavy-hitters: D3.js and Chart.js. But sometimes you don’t need a 500 pound gorilla. Sometimes you just want simple SVG charts that do exactly what you expect. That’s where Frappe Charts fits in. It’s a tiny, vanilla JS library that provides full-featured, animated, interactive

Introduction Docker Machine is a tool that makes it easy to provision and manage multiple Docker hosts remotely from your personal computer. Such servers are commonly referred to as Dockerized hosts, and as a matter of course, can be used to run Docker containers. While Docker Machine can be installed on a local or a

Introduction These days, more and more software projects are built by teams whose members work together from separate geographic locations. While this workflow has many clear advantages, there are cases where such teams might want to link their computers together across the internet and treat them as though they’re in the same room. For example,

The author selected the Tech Education Fund to receive a donation as part of the Write for DOnations program. ###Introduction Webmin is a web-based control panel for any Linux machine which lets you manage your server through a modern web-based interface. With Webmin, you can change settings for common packages on the fly, including web

SPAs (Single Page Applications) often consist of dozens or even hundreds of components that can be divided into several JavaScript bundle files. The goal of this post is to show one way to do this division and how to load each file asynchronously, only when the component is requested from a route change. This asynchronous

I recently released v-runtime-template, a Vue component that makes it easy to compile and interpret a Vue.js template at runtime by using a v-html-like API. I had a problem in a project where I had to receive a template from the server. Why you say? Well, imagine the usual drag ‘n drop interface that lets

Introduction Benchmarking allows you to estimate infrastructure performance so that you can determine whether or not a particular setup can serve your workload needs. This is an important component of maintaining high server performance and scaling to meet growing computing needs. With benchmark testing, you can monitor server resources, optimize for performance, manage utilization, and

When you pass a component to a function and it returns a new component, it’s called a higher-order component (HOC). If that sounds simple, it is! And your code will be simpler for using them. Over the course of this post, you’ll see how the higher-order component abstraction will enable your work to be more

The author selected the Tech Education Fund to receive a $300 donation as part of the Write for DOnations program. Introduction When problems arise, sending alerts to the appropriate team significantly speeds up identifying the root cause of an issue, allowing teams to resolve incidents quickly. Prometheus is an open-source monitoring system that collects metrics

The author selected the Tech Education Fund to receive a donation as part of the Write for DOnations program. Introduction Samba is an open-source implementation of the SMB/CIFS networking protocol used in Windows environments for shared services such as file and printer access and Active Directory. Samba can also be used to create cross-platform file

glamorous is a lightweight library for CSS-in-JS with a simple API that’s similar to styled-components’ and that makes use of glamor under the hood. Two of the main differences compared to styled-components is the use of JavaScript object literals and an additional API that allows to use DOM elements directly without creating additional named components.

Introduction Creating a mesh network across multiple Virtual Private Clouds (VPCs) is a powerful way to ensure seamless communication between your cloud resources while maintaining isolation and security. A VPC mesh network is a network topology where every VPC is connected to every other VPC, creating direct paths between all of them. This kind of

Introduction ClickHouse is an open-source columnar database management system that excels in high-performance OLAP queries and real-time analytics. However, scaling up data storage for ClickHouse can be challenging, especially as the volume of data grows. One efficient solution is to use tiered storage, which allows you to offload infrequently accessed data to a more cost-effective

Introduction The Vesta Control Panel is a free, open source control panel with website, email, database, and DNS functionalities. In this tutorial you will install the control panel on an Ubuntu or CentOS server, update the default admin interface port, and learn how to migrate user data from an existing installation. Note: On April 8th,

You might not have noticed yet, but several major apps are migrating away from the indefinite loading circle indicator paradigm (say that five times fast). Why? Because, while it’s better than nothing, it still makes users feel impatient waiting for their content to load. So what do they use instead? Loading placeholders. They’re usually low-contrast

Introduction Duplicity is a command-line utility written in Python that produces encrypted tar volumes for storage on a local or remote repository. It uses the GNU Privacy Guard (GPG) to encrypt and sign its archives and the rsync algorithm to create incremental, space-efficient backups. Backups can be transmitted to a variety of repositories, including local

As a developer, you’ve probably had to implement a big list or table for an app, either by loading lots of data without pagination, or using an infinite scroll pagination and scrolling several times through it. These lists or tables can become slow, especially when they have lots of elements, CSS styles and/or transitions. vue-virtual-scroller

Introduction Transporter is an open-source tool for moving data across different data stores. Developers often write one-off scripts for tasks like moving data across databases, moving data from files to a database, or vice versa, but using a tool like Transporter has several advantages. In Transporter, you build pipelines, which define the flow of data

Redux is a predictable state container for JavaScript apps, and a very valuable tool for organizing application state. It’s a popular library to manage state in React apps, but it can be used just as well with Angular, Vue.js or just plain old vanilla JavaScript. One thing most people find difficult about Redux is knowing

Introduction This tutorial will cover setting up a Hadoop cluster on DigitalOcean. The Hadoop software library is an Apache framework that lets you process large data sets in a distributed way across server clusters through leveraging basic programming models. The scalability provided by Hadoop allows you to scale up from single servers to thousands of

Box shadows are boring. You heard me. They can only use one color at a time and are slow to animate or transition. You know what would be neat? Making a drop shadow that would use the colors of the element’s background. So if the top left corner of your element was red, the top

The author selected the Diversity in Tech Fund to receive a donation as part of the Write for DOnations program. Introduction Jekyll is a static-site generator that provides some of the benefits of a Content Management System (CMS) while avoiding the performance and security issues introduced by such database-driven sites. It is “blog-aware” and includes

The author selected the Diversity in Tech fund to receive a donation as part of the Write for DOnations program. Introduction Prometheus is an open-source monitoring system that collects metrics from your services. Prometheus 2.0 brings many changes and improvements, such as a new time-series database, better resources usage, a new configuration format for alerts,