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Getting Started with Building Chatbots using AWS Lex and Node.js

Amazon and a lot of cloud vendors such as Microsoft and Google have services around machine learning (ML), artificial intelligence (AI), and virtual assistants. A popular one that might come to mind is Amazon Alexa, something I’ve written quite a few tutorials around over the years.

The concept around Alexa is simple. Provide the Alexa service some audio, have that audio converted into text or some other format that can be evaluated, execute some code, and respond with something to be spoken to the user. However, what if you didn’t necessarily want to use a virtual assistant with audio, but integrate as part of a chat application in the form of a chatbot?

In this tutorial we’re going to look at using Amazon Web Services (AWS) Lex, which is a service for adding conversational interfaces to your applications. If you’re coming from an Amazon Alexa background, the concepts will be similar as AWS Lex shares the same deep learning technologies.

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Password Hashing and JWTs for NativeScript Apps with an Express.js Backend

When building an application that allows users to have accounts, you have to ensure that access to these accounts is secure. When building a user account system, an important factor to keep in mind is how passwords are stored. Storing passwords as plain text is a complete rookie move that leaves your users vulnerable to all sorts of data breaches.

The best way to protect passwords is to employ hashing and salting and in this tutorial, we’ll show you exactly how to do this. We’ll also show you how to generate JSON Web Tokens (JWT) on a Node.js server backend that can be used to authenticate and authorize users, as well as how to store those tokens on the client NativeScript application.

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Using Socket.io to Create a Multiplayer Game with Angular and Node.js

When it comes to client and server communication, there are quite a few approaches towards solving the problem. You could create a RESTful API or GraphQL API on your server and consume it on-demand with your client, or you can go the socket approach and interact in real-time through events. There isn’t a wrong way to do things, but some ways are better than others given the task at hand.

Let’s take for example gaming and online multiplayer games. While certain aspects of the game would make sense to use REST or GraphQL, not everything would feel responsive enough. Instead it makes sense to use sockets.

In this tutorial we’re going to explore Socket.io for our client and server communication. We’re going to create a Socket.io server with Node.js and that server will communicate with each of our games running as Angular applications.

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Two-Factor Authentication With TOTP Using Node.js And Speakeasy

Almost two years ago I had written a tutorial around 2FA in a Node.js API with time-based one-time passwords. If you’re unfamiliar, two-factor authentication is becoming the norm, which it wasn’t necessarily back in 2017. If you’re managing user accounts in your web applications, it is critical that you offer your users a second factor of authentication to prevent phishing and malicious login attempts.

While the previous tutorial is still valid, it uses a less popular library to accomplish the task. This time around we’re going to explore using a more popular library called Speakeasy to manage two-factor authentication (2FA) within our Node.js with Express.js application.

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Fix GLIBCXX Errors From Serverless Framework And AWS Lambda

While I haven’t done too much with Serverless Framework and Functions as a Service (Faas) recently, I did in the past and it isn’t something that I’ve forgotten. In the past I demonstrated how to deploy Node.js functions to Amazon Web Services (AWS) Lambda that contain native dependencies. While not a necessity for all Lambda functions, it is for functions that use libraries for specific operating systems and architectures. For example, my previous article titled, Use AWS Lambda and API Gateway with Node.js and Couchbase NoSQL, fell into this situation. Making use of an EC2 instance or a Docker container with Amazon Linux will help most of the time, but there are scenarios where a little bit extra must be done to accomplish the task.

In certain circumstances everything may package and deploy correctly, but still throw errors. For example, a common error is around libstdc++ and a version of GLIBCXX not being found.

In this tutorial we’re going to see how to resolve library errors that might not be caught in a typical packaging and deployment scenario with Serverless Framework and AWS Lambda.

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Developing A GraphQL API With Node.js And MongoDB

While REST APIs are amongst the most popular when it comes to client consumption, they are not the only way to consume data and they aren’t always the best way. For example, having to deal with many endpoints or endpoints that return massive amounts of data that you don’t need are common. This is where GraphQL comes in.

With GraphQL you can query your API in the same sense that you would query a database. You write a query, define the data you want returned, and you get what you requested. Nothing more, nothing less. I actually had the opportunity to interview the co-creator of GraphQL on my podcast in an episode titled, GraphQL for API Development, and in that episode we discuss GraphQL at a high level.

You might remember that I wrote a tutorial titled, Getting Started with GraphQL Development Using Node.js which focused on mock data and no database. This time around we’re going to take a look at including MongoDB as our NoSQL data layer.

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Using Hapi.js, Mongoose, And MongoDB To Build A REST API

To continue on my trend of MongoDB with Node.js material, I thought it would be a good idea to use one of my favorite Node.js frameworks. Previously I had written about using Express.js with Mongoose, but this time I wanted to evaluate the same tasks using Hapi.js.

In this tutorial we’re going to develop a simple RESTful API using Hapi.js, Joi and Mongoose as the backend framework, and MongoDB as the NoSQL database. Rather than just using Hapi.js as a drop in framework replacement, I wanted to improve upon what we had previously seen, by simplifying functions and validating client provided data.

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