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
    LightFace: Facebook Lightbox for MooTools

    One of the web components I've always loved has been Facebook's modal dialog.  This "lightbox" isn't like others:  no dark overlay, no obnoxious animating to size, and it doesn't try to do "too much."  With Facebook's dialog in mind, I've created LightFace:  a Facebook lightbox...

  • By
    CSS Gradients

    With CSS border-radius, I showed you how CSS can bridge the gap between design and development by adding rounded corners to elements.  CSS gradients are another step in that direction.  Now that CSS gradients are supported in Internet Explorer 8+, Firefox, Safari, and Chrome...

Incredible Demos

  • By
    Form Element AJAX Spinner Attachment Using MooTools

    Many times you'll see a form dynamically change available values based on the value of a form field. For example, a "State" field will change based on which Country a user selects. What annoys me about these forms is that they'll often do an...

  • By
    Record Text Selections Using MooTools or jQuery AJAX

    One technique I'm seeing more and more these days (CNNSI.com, for example) is AJAX recording of selected text. It makes sense -- if you detect users selecting the terms over and over again, you can probably assume your visitors are searching that term on Google...

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!