Setting Environment Variables for Node to retrieve

Question 1

Environment variables (in this case) are being used to pass credentials to your application. USER_ID and USER_KEY can both be accessed from process.env.USER_ID and process.env.USER_KEY respectively. You don't need to edit them, just access their contents.

It looks like they are simply giving you the choice between loading your USER_ID and USER_KEY from either process.env or some specificed file on disk.

Now, the magic happens when you run the application.

USER_ID=239482 USER_KEY=foobar node app.js

That will pass the user id 239482 and the user key as foobar. This is suitable for testing, however for production, you will probably be configuring some bash scripts to export variables.

Question 2

I highly recommend looking into the dotenv package.

https://github.com/motdotla/dotenv

It's kind of similar to the library suggested within the answer from @Benxamin, but it's a lot cleaner and doesn't require any bash scripts. Also worth noting that the code base is popular and well maintained.

Basically you need a .env file (which I highly recommend be ignored from your git/mercurial/etc):

FOO=bar
BAZ=bob

Then in your application entry file put the following line in as early as possible:

require('dotenv').config();

Boom. Done. 'process.env' will now contain the variables above:

console.log(process.env.FOO);
// bar

The '.env' file isn't required so you don't need to worry about your app falling over in it's absence.

Question 3

You can set the environment variable through process global variable as follows:

process.env['NODE_ENV'] = 'production';

Works in all platforms.

Question 4

Just provide the env values on command line

USER_ID='abc' USER_KEY='def' node app.js

Question 5

If you want a management option, try the envs npm package. It returns environment values if they are set. Otherwise, you can specify a default value that is stored in a global defaults object variable if it is not in your environment.

Using .env ("dot ee-en-vee") or environment files is good for many reasons. Individuals may manage their own configs. You can deploy different environments (dev, stage, prod) to cloud services with their own environment settings. And you can set sensible defaults.

Inside your .env file each line is an entry, like this example:

NODE_ENV=development
API_URL=http://api.domain.com
TRANSLATION_API_URL=/translations/
GA_UA=987654321-0
NEW_RELIC_KEY=hi-mom
SOME_TOKEN=asdfasdfasdf
SOME_OTHER_TOKEN=zxcvzxcvzxcv

You should not include the .env in your version control repository (add it to your .gitignore file).

To get variables from the .env file into your environment, you can use a bash script to do the equivalent of export NODE_ENV=development right before you start your application.

#!/bin/bash
while read line; do export "$line";
done <source .env

Then this goes in your application javascript:

var envs = require('envs');

// If NODE_ENV is not set, 
// then this application will assume it's prod by default.
app.set('environment', envs('NODE_ENV', 'production')); 

// Usage examples:
app.set('ga_account', envs('GA_UA'));
app.set('nr_browser_key', envs('NEW_RELIC_BROWSER_KEY'));
app.set('other', envs('SOME_OTHER_TOKEN));

Question 6

It depends on your operating system and your shell

On linux with the shell bash, you create environment variables like this(in the console):

export FOO=bar

For more information on environment variables on ubuntu (for example):

Environment variables on ubuntu

Question 7

Windows-users: beware! These commands are recommended for Unix. But on Windows they don't persist, they only set a variable in your current shell, and it'll be gone when you restart.

SET TEST="hello world"
$env:TEST = "hello world"

3 ways to set a persistent environment variable on Windows:

A) .env file in your project - The best method. As you can just copy that file to any computer and get the same config when running the project.

Create an .env file in your project folder root with the content: TEST="hello world"
Write some node code that will read that file. I suggest installing dotenv ( npm install dotenv --save) and then add require('dotenv').config(); during your node setup code.
process.env.TEST is now usable in node

Env-files are a good way of keeping api-keys out of your codebase

B) Use Powershell - this will create a variable that will be accessible in other terminals. But it sucks as it'll be lost after you restart your computer.

[Environment]::SetEnvironmentVariable("TEST", "hello world", "User")

This method is widely recommended on Windows forums, people seem unaware it doesn't persist after a system restart....

C) Use the Windows GUI

Search for "Environment Variables" in the Start Menu Search or in the Control Panel, Select "Edit the system environment variables". A dialogue opens and you click the button "Environment Variables" at the bottom of the dialogue to open an edit-view where you can click the "New" button to add a new environment variable. Easy. And persists even after a restart. But not something you should use to config a specific codebase.

Question 8

Like ctrlplusb said, I recommend you to use the package dotenv, but another way to do this is creating a js file and requiring it on the first line of your app server.

env.js:

process.env.VAR1="foo"
process.env.VAR2="bar"

app.js:

require('./env') // env.js relative path.
console.log(process.env.VAR1) // foo

Question 9

Step 1: Add your environment variables to their appropriate file. For example, your staging environment could be called .env.staging, which contains the environment variables USER_ID and USER_KEY, specific to your staging environment.

Step 2: In your package.json file, add the following:

"scripts": {
  "build": "sh -ac '. ./.env.${REACT_APP_ENV}; react-scripts build'",
  "build:staging": "REACT_APP_ENV=staging npm run build",
  "build:production": "REACT_APP_ENV=production npm run build",
  ...
}

then call it in your deploy script like this:

npm run build:staging

Super simple set up and works like a charm!

Source: https://medium.com/@tacomanator/environments-with-create-react-app-7b645312c09d

Question 10

Make your life easier with dotenv-webpack. Simply install it npm install dotenv-webpack --save-dev, then create an .env file in your application's root (remember to add this to .gitignore before you git push). Open this file, and set some environmental variables there, like for example:

ENV_VAR_1=1234
ENV_VAR_2=abcd
ENV_VAR_3=1234abcd

Now, in your webpack config add:

const Dotenv = require('dotenv-webpack');
const webpackConfig = {
  node: { global: true, fs: 'empty' }, // Fix: "Uncaught ReferenceError: global is not defined", and "Can't resolve 'fs'".
  output: {
    libraryTarget: 'umd' // Fix: "Uncaught ReferenceError: exports is not defined".
  },
  plugins: [new Dotenv()]
};
module.exports = webpackConfig; // Export all custom Webpack configs.

Only const Dotenv = require('dotenv-webpack');, plugins: [new Dotenv()], and of course module.exports = webpackConfig; // Export all custom Webpack configs. are required. However, in some scenarios you might get some errors. For these you have the solution as well implying how you can fix certain error.

Now, wherever you want you can simply use process.env.ENV_VAR_1, process.env.ENV_VAR_2, process.env.ENV_VAR_3 in your application.

Question 11

If you are using a mac/linux and you want to retrieve local parameters to the machine you're using, this is what you'll do:

In terminal run nano ~/.zshrc
add a line like: export MY_VAR=var
save & run source ~/.zshrc
in node use like: console.log(process.env.MY_VAR);

Replace .zshrc with .bashrc or your config file, depending on what shell you're using (and replace nano with your preferred editor).

Question 12

For windows users this Stack Overflow question and top answer is quite useful on how to set environement variables via the command line

How can i set NODE_ENV=production in Windows?

Question 13

Came across a nice tool for doing this.

node-env-file

Parses and loads environment files (containing ENV variable exports) into Node.js environment, i.e. process.env - Uses this style:

.env

# some env variables

FOO=foo1
BAR=bar1
BAZ=1
QUX=
# QUUX=

Question 14

As expansion of @ctrlplusb answer,
I would suggest you to also take a look to the env-dot-prop package.

It allows you to set/get properties from process.env using a dot-path.

Let's assume that your process.env contains the following:

process.env = {
  FOO_BAR: 'baz'
  'FOO_🦄': '42'
}

Then you can manipulate the environment variables like that:

const envDotProp = require('env-dot-prop');

console.log(process.env);
//=> {FOO_BAR: 'baz', 'FOO_🦄': '42'}

envDotProp.get('foo');
//=> {bar: 'baz', '🦄': '42'}

envDotProp.get('foo.🦄');
//=> '42'

envDotProp.get('foo.🦄', {parse: true});
//=> 42

envDotProp.set('baz.foo', 'bar');
envDotProp.get('', {parse: true});
//=> {foo: {bar: 'baz', '🦄': 42}, baz: {foo: 'bar'}}

console.log(process.env);
//=> {FOO_BAR: 'baz', 'FOO_🦄': '42', BAZ_FOO: 'bar'}

envDotProp.delete('foo');
envDotProp.get('');
//=> {baz: {foo: 'bar'}}

console.log(process.env);
//=> {BAZ_FOO: 'bar'}

This helps you to parse the environment variables and use them as a config object in your app.
It also helps you implement a 12-factor configuration.

Question 15

A very good way of doing environment variables I have successfully used is below:

A. Have different config files:

dev.js // this has all environment variables for development only
The file contains:

module.exports = {
 ENV: 'dev',
 someEnvKey1 : 'some DEV Value1',
 someEnvKey2 : 'some DEV Value2'
};

stage.js // this has all environment variables for development only
```
..
```

qa.js // this has all environment variables for qa testing only
The file contains:

module.exports = {
 ENV: 'dev',
 someEnvKey1 : 'some QA Value1',
 someEnvKey2 : 'some QA Value2'
};

NOTE: the values are changing with the environment, mostly, but keys remain same.

you can have more
z__prod.js // this has all environment variables for production/live only
NOTE: This file is never bundled for deployment

Put all these config files in /config/ folder

<projectRoot>/config/dev.js
<projectRoot>/config/qa.js
<projectRoot>/config/z__prod.js
<projectRoot>/setenv.js
<projectRoot>/setenv.bat
<projectRoot>/setenv.sh

NOTE: The name of prod is different than others, as it would not be used by all.

B. Set the OS/ Lambda/ AzureFunction/ GoogleCloudFunction environment variables from config file

Now ideally, these config variables in file, should go as OS environment variables (or, LAMBDA function variables, or, Azure function variables, Google Cloud Functions, etc.)

so, we write automation in Windows OS (or other)

Assume we write 'setenv' bat file, which takes one argument that is environment that we want to set
Now run "setenv dev"

a) This takes the input from the passed argument variable ('dev' for now)
b) read the corresponding file ('config\dev.js')
c) sets the environment variables in Windows OS (or other)

For example,

The setenv.bat contents might be:

    node setenv.js

The setenv.js contents might be:

    // import "process.env.ENV".js file (dev.js example)
    // loop the imported file contents
    //     set the environment variables in Windows OS (or, Lambda, etc.)

That's all, your environment is ready for use.

When you do 'setenv qa', all qa environment variables will be ready for use from qa.js, and ready for use by same program (which always asks for process.env.someEnvKey1, but the value it gets is qa one).

Hope that helps.

Question 16

Pretty much like some others answers but without any lib nor (bash) export.

I have some encrypted variables then I need to generate them on the fly.

The magic happens with set -a && ... && set +a which can be some content or a file.

#!/bin/sh

set -a    
SOMEVAR_A="abcd"
SOMEVAR_B="efgh"
SOMEVAR_C=123456
set +a

# or
set -a && . ./file && set +a

I have a docker-entrypoint.sh with:

#!/bin/sh

node app/config/set-environment.js

ENVFILE=/tmp/.env

if [[ ! -f "$ENVFILE" ]] ; then
    echo "File $ENVFILE is not there, aborting."
    exit
fi

# here is where things happen
set -a && . $ENVFILE && set +a

if [ "${NODE_ENV}" = "development" ]; then
  npx nodemon app/server.js
else
  node app/server.js
fi

exec "$@"

While set-environment.js generates a (tmp) .env file

Question 17

I was getting undefined after setting a system env var. When I put APP_VERSION in the User env var, then I can display the value from node via process.env.APP_VERSION

Question 18

in case you're using visual studio code debugging feature, you can add "envFile": "${workspaceRoot}/.env" to launch configuration. This way you don't have to use dotenv.

{
        "cwd": "${workspaceRoot}",
        "command": "npm start",
        "name": "Run be",
        "request": "launch",
        "type": "node-terminal",
        "envFile": "${workspaceRoot}/.env"
},

Question 19

Make a file called local-env and populate it with variables

PORT=80
DB_NAME=foo
SOME_URL=example.com

Now run node thusly:

source ./local_env ; node index.js

Question 20

Use cross-env. It will save you a lot of headache

npm i -S cross-env

cross-env PARAM=value node ./index.js

That's usually good for non-credentials. For things like credentials and keys it's better not to store hardcoded user id and password but use .env file which is not in repo and dotenv