Running NodeJS Forever!

Chance Murray — Fri, 09 Mar 2018 05:02:09 +0000

Introduction

NodeJS is a great tool for web development, but it has it’s hang-ups. When setting up an Express Server with NodeJS, many restarts are required and expected during the development stage. Not only that, but it would be great to keep a NodeJS project running indefinitely once you close your terminal session. This tutorial aims to address both of those issues. This tutorial will start by addressing the desire to keep a nodeJS process running and will then address reloading the process when changes are made. I will do this by addressing different tools used to accomplish these tasks and will end with my preferred option. Let’s begin.

NOTE: THIS IS COPIED FROM A WORDPRESS BLOG AND THEREFORE SOME STYLES AND TEXT DID NOT TRANSFER OVER PROPERLY

Video (for all of you non-readers out there)

The Options:

Tmux/Screen (Okay Option)

Tmux and Screen are terminal multiplexers that allow you to create “sessions” that can persist after you close your terminal. They create their own sockets that a terminal instance runs in. A user can then access this through their tool’s commands. Once inside one of these sessions, running a command with node and then leaving the session will not end the node process because the terminal session is still open. I won’t go into detail here, but if you watch the video, I will show how to do this with tmux.

Nodemon (Better Option)

One of the issues with the above method is that you still need to stop and restart the node process every time you make a change to the server. One work-around for this is to install nodemon, a nodejs wrapper that watches the files in the directory it is run it and restarts. Nodemon is a node module and can be installed with npm. Combining nodemon with tmux or screen will allow you to run a node server that restarts whenever a change occurs. There is an easier way.

PM2 (Best Option)

PM2 is a Process Manager for NodeJS. Like nodemon, it is also installed globally through npm. Unlike nodemon, pm2 actually creates a system process independent of any terminal instance to run your node process in. The video shows how to set it up after installing so I won’t discuss it here. They have some great documentation at their site.

Conclusion

There are different ways to accomplish the task of running node forever, but my favorite, since I first started using it, is PM2. It allows users to monitor multiple node processes, watch the files for changes, and even run in a clustered mode for load-balancing purposes.

Setting up a basic ExpressJS App with NodeJS

Chance Murray — Tue, 13 Feb 2018 22:50:08 +0000

Introduction

If you want to get started with NodeJS web apps, here’s a great place to start. We will build a basic app that displays Quotes on a page. This tutorial covers the following steps:

Setting up a NodeJS project
Creating a web server with express
Using the EJS template engine library
Sending external data to our templates with Express Middleware

NOTE: THIS IS COPIED FROM A WORDPRESS BLOG AND THEREFORE SOME STYLES AND TEXT DID NOT TRANSFER OVER PROPERLY

Setup

For this tutorial, I will assume you have NodeJS and NPM installed on your development environment. If you don’t have either of those things installed, I recommend the following links depending on your operating system:

Windows
- http://lmgtfy.com/?q=Install+NodeJS+and+NPM+on+Windows
Linux (Ubuntu) and Mac OS X
- http://nodesource.com/blog/installing-node-js-tutorial-using-nvm-on-mac-os-x-and-ubuntu/

For this tutorial I will be using Node version 8.9.4 and NPM version 5.6.0.

If you have Node and NPM installed, running the following commands in your terminal will check the versions:

NODE VERSION:
- node -v
NPM VERSION:
- npm -v

Lastly, you should have a good code editor ready. I use Visual Studio Code. It is a great editor, with a built-in file manager and an integrated terminal. You can download it from this site.

Now that you are set up, it is time to start coding!

Video (for all of you non-readers out there)

Walk-through

Creating A Node Project

Start by creating a directory you would like to work out of. Mine is ~/myapp. Using your terminal, move into this directory and run the following command:npm init -y.

This should have created a package.json file in your directory. Create a file that matches the “main” key in you package.json file. My file is index.js. Now that we have the project ready, we can move on.

Installing Dependencies

For the app we will be using Express as our web server so we need to install the Express module using npm. From your project directory open a terminal and run the command npm i -s express ejs. You should now have a node_modules directory. Express and the EJS template engine were installed in that directory.

Creating your Express App

You need to pull express from the node_modules folder and use it in your index.js file. to do this, add the following lines to the top of index.js:

var express = require('express') var app = express()

This creates an app using express that we will add functionality to in the next steps.

In order to run the express app, you need to add the following line to the bottom of your index.js file:

app.listen(3000)

This runs your server at “http://localhost:3000”.

Keep this line at the bottom of your index.js file. Whenever we add more code to the page, we will add it above this line.

Serving Static Files

We need a folder that we can serve our static files (css, images, javascript, etc.) from.

Create a folder called ‘public’ in your directory. This will hold our static files.

Add the following line to your index.js file:

app.use(express.static('public'))

Whe a static resource is requested, your app will now look in the public folder. as a note, the app does nnot consider the name of the public foldder in the request. For example, f the page looks for ‘js/test.js’, you app will look for it in ‘public/js/test/js’.

Adding Routes

Our first route will handle a simple GET request to our base route ‘/’. This means that any GET request sent specifically to “http://localhost:3000” will be handled by this route. This is where we will eventually have the logic for our main page.

To get started, add the following lines to your index.js file:

app.get('/', function (req, res) { res.send('HELLO WORLD') })

You can test to see if this works by opening a terminal in your directory and running node index.js. Once you have done that, you can navigate to ‘http://localhost:3000’in your browser and you should see your content.

Creating a View Template with EJS

This takes a few steps. First, create a ‘views’ folder in your app directory. Next, create a file in your ‘views’ directory called ‘index.ejs’. Put the following content in that file:

`<!DOCTYPE html>

Quotes .quote{ border: 2px solid black; margin: 5px; }

Quotes:

Next, you have to tell the app to render this file when the ‘/’ route is requested.

To do this, you first need to add the following two lines to your ‘index.js’ file before your route, and after you declare ‘app’:

app.set('views', 'views'); app.set('view engine', 'ejs');

Last, you need to tell the app to render the file by replacing res.send('HELLO WORLD') in your route with the following line:

res.render('index')

If you run your server, it should show you your template file with an example quote.

We are ready for the final step.

Sending Data to the View

To accomplish this step, we are going to need to do some setup. First, we will need to create a folder called ‘controllers’ that will contain all of our data-handling files and functions. Net, we will create a file called ‘quotes.js’ in our controllers folder. In that file, we will add some dummy data:

var data = [ { author: "Chance", quote: "Cliche web tutorials are lame." }, { author: "Yoda", quote: "Do, or do not. There is no 'try'" }, { author: "Ben Franklin", quote: "A penny saved is a penny earned." }, { author: "Dr. Seuss", quote: "Don't cry because it's over, smile becuse it happened." } ]

Next, we will export a function that our app can use to get this data:

exports.getData = function() { return { quotes: data } }

In ‘index.js’, we need to require the controller. to do this, add the line var Quotes = require('./controllers/quotes'); before your route.

Now that we have the data, we need to send it to our view. Replace res.render('index') in our route with:

res.render('index', Quotes.getData())

The view now has the data. Replacing the example div with the following code will allow the view to loop through the data and print it to the page:

`<% for (quote of quotes) { %>

<%=quote.quote%>

~ <%=quote.author%>

<%}%>`

Conclusion

We did it! Hopefully this tutorial was able to help you with some of the basics of Express, EJS, and NodeJS.

Thank you for taking the time to read through my first tutorial!

DEV Community: Chance Murray

Running NodeJS Forever!

Introduction

Video (for all of you non-readers out there)

The Options:

Tmux/Screen (Okay Option)

Nodemon (Better Option)

PM2 (Best Option)

Conclusion

Setting up a basic ExpressJS App with NodeJS

Introduction

Setup

Video (for all of you non-readers out there)

Walk-through

Creating A Node Project

Installing Dependencies

Creating your Express App

Serving Static Files

Adding Routes

Creating a View Template with EJS

Quotes:

Sending Data to the View

Conclusion