Managing Environment Variables in Node.js with dotenv

Originally published by Marcus Sanatan at


Deploying an application requires developers to put thought and consideration into how it is configured. Many apps are deployed in a development environment before being deployed to the production environment. We need to ensure each environment is configured correctly, it could be disastrous if our production application was using our development database, for example.

Environment variables allow us to manage the configuration of our applications separate from our codebase. Separating configurations make it easier for our application to be deployed in different environments.

Large applications tend to have many environment variables. To better manage them we can use the dotenv library, which allows us to load environment variables from a file.

What are Environment Variables?

From programming we know that variables are stored values that can be changed. They're mutable and can vary - hence the name variables.

Environment variables are variables external to our application which reside in the OS or the container of the app is running in. An environment variable is simply a name mapped to a value.

By convention, the name is capitalized e.g. The values are strings.

If you open the terminal or command line application in Linux, Mac OS, or Windows and enter set, you will see a list of all environment variables for your user.

Why use Environment Variables?

Environment variables are excellent for decoupling application configurations. Typically, our applications require many variables to be set in order for them to work. By relying on external configurations, your app can easily be deployed on different environments. These changes are independent of code changes, so they do not require your application to be rebuilt to change.

Data which changes depending on the environment your app is running on should be set as environment variables. Some common examples are:

  • HTTP Port and Address
  • Database, cache, and other storage connection information
  • Location of static files/folders
  • Endpoints of external services
  • For example, on a development environment your app will point to a test API URL, whereas in a production environment your app will point to the live API URL.

Sensitive data like API keys should not be in the source code, or known to persons who do not need access to those external services.

Environment Variables in Node.js

Consider a hello world Node.js application with environment variables for the host and port the app runs on.

Create a new file called hello.js in a workspace of your choosing and add the following:

const http = require('http');

// Read the host address and the port from the environment
const hostname = process.env.HOST;
const port = process.env.PORT;

// Return JSON regardless of HTTP method or route our web app is reached by
const server = http.createServer((req, res) => {
res.statusCode = 200;
res.setHeader(‘Content-Type’, ‘application/json’);
res.end({"message": "Hello World"});

// Start a TCP server listening for connections on the given port and host
server.listen(port, hostname, () => {
console.log(Server running at http://${hostname}:${port}/);

Node.js provides a global variable process.env, an object that contains all environment variables available to the user running the application. It is expecting the hostname and the port that the app will run on to be defined by the environment.

You can run this application by entering this command in the terminal, HOST=localhost PORT=3000 node hello.js, granted you have Node.js installed. You will notice the following message on your console:

Server running at http://localhost:3000/

Creating and reading environment variables is that easy. Let’s say we are writing a micro-service which communicates with a MySQL and Redis instance, we would like to have the connection details available in our environment variables as well.

We might end up with a command like this:

$ DB_HOST=localhost DB_PORT=3306 DB_USER=test DB_PASSWORD=verySecret123!$ DB_MAX_CONNECTIONS=15 CACHE_ADDR=localhost CACHE_PORT= 6379 HOST=localhost PORT=3000 node hello.js

Developing with multiple environment variables quickly become unwieldy. It would be better if the environment variables we had to configure were stored in one central place to the application, like a file.

The dotenv Library

This library does one simple task: loads environment variables from a .env file into the process.envvariable in Node.js. Let’s use dotenv for the previous example.

First, we need to install it via npm:

$ npm init # Optional, creates a local package.json that prevents global installs
$ npm install dotenv --save

And then we make one minimal code change, add this line to the top of hello.js:


Now in the same directory of your app, create a new file called .env and add the following:


Your environment variables are declared just as if you were entering them in the shell before running the node command. Instead of separating each variable assignment by a space, we separate them by a newline. Now in your shell, if you enter node hello.js, the app will be running on port 3000 on your localhost!

Even if dotenv is used in the application, it is completely optional. If no .env file is found, the library fails silently. You can continue to use environment variables defined outside the file.

Note: There are also many variations of dotenv across other programming languages and frameworks. A very popular guideline for building modern web applications is The Twelve-Factor App. The document was created by many developers who created Software-as-a-Service applications. One of the 12 considerations of a modern, scalable app is configuration, specifically the use of environment variables to store configuration. The popularity of this methodology has helped fuel the creation and popularity of dotenv and similar modules.

Production Usage

Storing your environment variables in a file comes with one golden rule: never commit it to the source code repository. You do not want outsiders gaining access to secrets, like API keys. If you are using dotenv to help manage your environment variables, be sure to include the .env file in your .gitignore or the appropriate blacklist for your version control tool.

If you cannot commit the .env file, then there needs to be some way for a developer to know what environment variables are required to run the software. It is common for developers to list the environment variables necessary to run the program in a README or similar internal documentation.

Some developers create and maintain a .sample-env file in the source code repository. This sample file would list all the environment variables used by the app, for example:


A developer would then clone the repository, copy the .sample-env file into a new .env file and fill in the values.

If your app is running on a physical machine or a virtual machine (for example, Digital Ocean dropletsAmazon EC2 and Azure Virtual Machines), then you can create a .env while logged into the server and it would run just as it is done on your local machine.

If your app is running on a docker container or a Platform-as-a-Service provider like Heroku or Openshift, then you will be able to configure environment variables without having to use the .envfile.

Remember, it fails silently so it would not affect the running of the app if the file is missing.


Environment variables exist outside our application’s code, they are available where our application is running. They can be used to decouple our application’s configuration from its code, which allows our apps to be easily deployed across different environments.

With Node.js apps, environment variables are available through the process.env global variable. We can set the environment variables before we run the node command, or we can use the dotenvlibrary which allows us to define our environment variables in a .env file.

The .env file should never be in the source code repository.

Originally published by Marcus Sanatan at


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Managing Environment Variables in Node.js with dotenv

Hire Dedicated Node.js Developers - Hire Node.js Developers

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Why use Node.js for Web Development? Benefits and Examples of Apps

Front-end web development has been overwhelmed by JavaScript highlights for quite a long time. Google, Facebook, Wikipedia, and most of all online pages use JS for customer side activities. As of late, it additionally made a shift to cross-platform mobile development as a main technology in React Native, Nativescript, Apache Cordova, and other crossover devices. 

Throughout the most recent couple of years, Node.js moved to backend development as well. Designers need to utilize a similar tech stack for the whole web project without learning another language for server-side development. Node.js is a device that adjusts JS usefulness and syntax to the backend. 

What is Node.js? 

Node.js isn’t a language, or library, or system. It’s a runtime situation: commonly JavaScript needs a program to work, however Node.js makes appropriate settings for JS to run outside of the program. It’s based on a JavaScript V8 motor that can run in Chrome, different programs, or independently. 

The extent of V8 is to change JS program situated code into machine code — so JS turns into a broadly useful language and can be perceived by servers. This is one of the advantages of utilizing Node.js in web application development: it expands the usefulness of JavaScript, permitting designers to coordinate the language with APIs, different languages, and outside libraries.

What Are the Advantages of Node.js Web Application Development? 

Of late, organizations have been effectively changing from their backend tech stacks to Node.js. LinkedIn picked Node.js over Ruby on Rails since it took care of expanding responsibility better and decreased the quantity of servers by multiple times. PayPal and Netflix did something comparative, just they had a goal to change their design to microservices. We should investigate the motivations to pick Node.JS for web application development and when we are planning to hire node js developers. 

Amazing Tech Stack for Web Development 

The principal thing that makes Node.js a go-to environment for web development is its JavaScript legacy. It’s the most well known language right now with a great many free devices and a functioning local area. Node.js, because of its association with JS, immediately rose in ubiquity — presently it has in excess of 368 million downloads and a great many free tools in the bundle module. 

Alongside prevalence, Node.js additionally acquired the fundamental JS benefits: 

  • quick execution and information preparing; 
  • exceptionally reusable code; 
  • the code is not difficult to learn, compose, read, and keep up; 
  • tremendous asset library, a huge number of free aides, and a functioning local area. 

In addition, it’s a piece of a well known MEAN tech stack (the blend of MongoDB, Express.js, Angular, and Node.js — four tools that handle all vital parts of web application development). 

Designers Can Utilize JavaScript for the Whole Undertaking 

This is perhaps the most clear advantage of Node.js web application development. JavaScript is an unquestionable requirement for web development. Regardless of whether you construct a multi-page or single-page application, you need to know JS well. On the off chance that you are now OK with JavaScript, learning Node.js won’t be an issue. Grammar, fundamental usefulness, primary standards — every one of these things are comparable. 

In the event that you have JS designers in your group, it will be simpler for them to learn JS-based Node than a totally new dialect. What’s more, the front-end and back-end codebase will be basically the same, simple to peruse, and keep up — in light of the fact that they are both JS-based. 

A Quick Environment for Microservice Development 

There’s another motivation behind why Node.js got famous so rapidly. The environment suits well the idea of microservice development (spilling stone monument usefulness into handfuls or many more modest administrations). 

Microservices need to speak with one another rapidly — and Node.js is probably the quickest device in information handling. Among the fundamental Node.js benefits for programming development are its non-obstructing algorithms.

Node.js measures a few demands all at once without trusting that the first will be concluded. Many microservices can send messages to one another, and they will be gotten and addressed all the while. 

Versatile Web Application Development 

Node.js was worked in view of adaptability — its name really says it. The environment permits numerous hubs to run all the while and speak with one another. Here’s the reason Node.js adaptability is better than other web backend development arrangements. 

Node.js has a module that is liable for load adjusting for each running CPU center. This is one of numerous Node.js module benefits: you can run various hubs all at once, and the environment will naturally adjust the responsibility. 

Node.js permits even apportioning: you can part your application into various situations. You show various forms of the application to different clients, in light of their age, interests, area, language, and so on. This builds personalization and diminishes responsibility. Hub accomplishes this with kid measures — tasks that rapidly speak with one another and share a similar root. 

What’s more, Node’s non-hindering solicitation handling framework adds to fast, letting applications measure a great many solicitations. 

Control Stream Highlights

Numerous designers consider nonconcurrent to be one of the two impediments and benefits of Node.js web application development. In Node, at whatever point the capacity is executed, the code consequently sends a callback. As the quantity of capacities develops, so does the number of callbacks — and you end up in a circumstance known as the callback damnation. 

In any case, Node.js offers an exit plan. You can utilize systems that will plan capacities and sort through callbacks. Systems will associate comparable capacities consequently — so you can track down an essential component via search or in an envelope. At that point, there’s no compelling reason to look through callbacks.


Final Words

So, these are some of the top benefits of Nodejs in web application development. This is how Nodejs is contributing a lot to the field of web application development. 

I hope now you are totally aware of the whole process of how Nodejs is really important for your web project. If you are looking to hire a node js development company in India then I would suggest that you take a little consultancy too whenever you call. 

Good Luck!

Original Source

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Node.js is a prominent tech trend in the space of web and mobile application development. It has been proven very efficient and useful for a variety of application development. Thus, all business owners are eager to leverage this technology for creating their applications.

Are you striving to develop an application using Node.js? But can’t decide which company to hire for NodeJS app development? Well! Don’t stress over it, as the following list of NodeJS app development companies is going to help you find the best partner.

Let’s take a glance at top NodeJS application development companies to hire developers in 2021 for developing a mind-blowing application solution.

Before enlisting companies, I would like to say that every company has a foundation on which they thrive. Their end goals, qualities, and excellence define their competence. Thus, I prepared this list by considering a number of aspects. While making this list, I have considered the following aspects:

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  • Enlisted by software peer & forums
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  • Year of experience (Average 8+ years)
  • Credibility & Excellence
  • Served clients and more

I believe this list will help you out in choosing the best NodeJS service provider company. So, now let’s explore the top NodeJS developer companies to choose from in 2021.

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If you want to hire NodeJS developers to secure an outstanding application, I would definitely suggest them. They serve in the area of eLearning, FinTech, eCommerce, Telecommunications, Mobile Device Management, and more.

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  • Founded: 2006

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