Popular:
 Building Resilient Systems on AWS: Learn how to design and implement a resilient, highly available, fault-tolerant infrastructure on AWS.

Get and Set Environment Variables in Node.js

By  on  

One of the best ways to use sensitive information in open source repositories without hard-coding the information within publicly available repositories is setting environment variables.  Set the environment variables on the server, retrieve them by key within your application.

When using Node.js, you can retrieve environment variables by key from the process.env object:

var mode = process.env.mode; // 'PRODUCTION', for example

var apiKey = process.env.apiKey; // '38294729347392432'

There are time when you may want to set environment variables while you run your node app -- these are set temporarily while the process is still running.  A common case is simulating environment variables during testing.  You can temporarily set these variables by pegging items onto the process.env object:

process.env.mode = 'TESTING';

// Now app code knows not to do destructive transactions!

Simple enough but worth documenting for future use!

Request Metrics real user monitoring
Request Metrics real user monitoring
Request Metrics real user monitoring
Request Metrics real user monitoring

Recent Features

  • By
    Animated 3D Flipping Menu with CSS

    CSS animations aren't just for basic fades or sliding elements anymore -- CSS animations are capable of much more.  I've showed you how you can create an exploding logo (applied with JavaScript, but all animation is CSS), an animated Photo Stack, a sweet...

  • By
    Conquering Impostor Syndrome

    Two years ago I documented my struggles with Imposter Syndrome and the response was immense.  I received messages of support and commiseration from new web developers, veteran engineers, and even persons of all experience levels in other professions.  I've even caught myself reading the post...

Incredible Demos

  • By
    iPhone-Style Passwords Using MooTools PassShark

    Every once in a while I come across a plugin that blows me out of the water and the most recent culprit is PassShark: a MooTools plugin that duplicates the iPhone's method of showing/hiding the last character in a password field. This gem of...

  • By
    spellcheck Attribute

    Many useful attributes have been provided to web developers recently:  download, placeholder, autofocus, and more.  One helpful older attribute is the spellcheck attribute which allows developers to  control an elements ability to be spell checked or subject to grammar checks.  Simple enough, right?

Discussion

  1. Kristjan

    I believe it’s more common to use process.env.NODE_ENV instead of process.env.mode

  2. Blaine

    This is an interesting problem. What if you are using aws or heroku for hosting? You could have your deployment script setup the keys, but you’d need to prompt each time you create a new instance.

    I encrypted the keys in a json file with AES 256 and in my run/deploy script it prompts for a password and decrypts it running the rest of the application with env variables. It’s not perfected yet, but this might be a good way to put it on github.

  3. Caleb

    Are these variables just being set via the command line?

  4. Ola

    I have had great success with json-configurator (https://www.npmjs.com/package/json-configurator). Use it with process.env.NODE_ENV as a input.

    require('json-configurator')(configJson, process.env.NODE_ENV ).userEndpoint;
  5. xgqfrms
    # Windows:

SET NODE_ENV=development
# or
set NODE_ENV=development


# OS X / Linux:

export NODE_ENV=development



# Windows CMD
set NODE_ENV=production


# Windows PowerShell:
$env:NODE_ENV="production"

Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!