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Env

.env file​

  • Environment variables in Node are used to store sensitive data such as passwords, API credentials, and other information that should not be written directly in code
HOST = 192.168.1.10
DBPORT = 3306
DBNAME = mydb
DBUSER = apiuser
DBPWD = 123456
PORT = 3001

Change Environment​

console.log(process.env.NODE_ENV);	//default is undefined
console.log(app.get('env'));  //default env is development

//we can define current environment in console
> $env:NODE_ENV='developement'
> $env:NODE_ENV='testing'
> $env:NODE_ENV='production'

Get environment variables​

const dotenv = require('dotenv');
dotenv.config({path:'./.env'});

console.log(process.env.NODE_ENV);  //what is our current running environment, default is undefined
console.log(app.get('env'));        //default env is development
console.log(process.env.DBNAME);    //what is set inside env file
console.log(process.env.DBUSER);    //what is set inside env file
console.log(process.env.DBPWD);    //what is set inside env file

//e.g. use it to connect to mongodb
mongoose.connect('mongodb://' + process.env.HOST + ':' + process.env.DBPORT + '/' + process.env.DBNAME)
  .then(()=>console.log("connected to mongodb"))
  .catch(error=>console.log("connection to mongodb failed",error))

app.listen(process.env.PORT,()=>{
  console.log('api listening at port '+ process.env.PORT);
});

Log when env is in development​

const exporess = require('express');
const morgan = require('morgan');
const app = express();

if(app.get('env')==='development'){
	appuse(morgan('tiny'));
}

Set env to production​

$ export NODE_ENV=production
$ nodemon

Different config files for each environments​

//install config package
$ npm i config

//then create a directory config, inside it, create 3 files
//default.json
{
	"name":"myapp - development",
	"dbhost":"localhost",
	"dbname":"myapp-dev"
}
//development.json
{
	"name":"myapp - development",
	"dbhost":"localhost",
	"dbname":"myapp-dev"
}
//production.json
{
	"name":"myapp - production",
	"dbhost":"localhost",
	"dbname":"myapp-prod"
}

//now we can use in index.js
const config = require('config');

console.log(config.get('name'));
console.log(config.get('dbhost'));
console.log(config.get('dbname'));

//when we change env to production by 
//$ export NODE_ENV=production 
//and restart the app, the values will correspond to our settings

store sensitive info in custom environment variables​

//create a file called custom-environment-variables.json
//this file only has mapping of env variables
{
	"password":"PASSWORD"			//the actual PASSWORD is set in the .env file, here is a mapping of that password
}

//and in the .env file
PASSWORD=123456

//now we can use in index.js
const config = require('config');

console.log(config.get('password'));