assert-dotenv

assert-dotenv = dotenv + dotenv-assert

One fell swoop for loading and asserting environment settings in node.

Version 3.0.0

• This module now fully supports sync and async execution
  • Synchronous execution throws errors (when errors)
  • Asnychronous execution passes errors to the error-first callback

Why use assert-dotenv

• Storing configuration in the environment is one of the tenets of a twelve-factor app.
• Implicit default settings can lead to confusing troubleshooting scenarios and should be avoided entirely.
• The assert.env file only lists what environment settings (keys) are required without providing values like private tokens, passwords, etc. and therefore can and should be checked into version control repositories.
  • .env files contain setting keys and values, therefore, they should not be checked into version control repositories.

How does it work

An exception is thrown if any of these cases are true:

• An assert.env (or otherwise specified) file is not found
• The keys listed in the assert.env file are not set on the process.env node object

Otherwise, your environment settings are applied and your application executes as expected.

Installation

$ npm install --save assert-dotenv

Usage

/**
*  Synchronously load .env and assert.env files from CWD or
*  from the nearest parent directory where they are found.
*/
require('assert-dotenv')();
 
/**
*  or, specify custom file locations and/or file names
*
*  CAVEAT: specifying a filename (without a path) will cause
*  the file to be loaded from CWD or the nearest parent
*  directory where it is found.
*/
require('assert-dotenv')({
  dotenvFile: '../configs/.env.staging',
  assertFile: 'assert.env.staging'
});
 
/**
*  Asynchronous execution occurs when you provide a callback
*/
require('assert-dotenv')(function(error){
  if(error) throw error;
 
  console.log('Environment Settings Loaded and Asserted!');
});
 
/**
*  also, you can async with options
*/
require('assert-dotenv')({
  dotenvFile: 'dev.env',
  assertFile: 'assert.dev.env'
}, function(error){
  if(error) throw error;
 
  console.log('Environment Settings Loaded and Asserted!');
});

Simple HTTP Server Example

• ~/app/.env

  IP=127.0.0.1
  PORT=1337
  

• ~/app/assert.env

  IP
  PORT
  

• ~/app/index.js

  • Synchronous Example

    require('assert-dotenv')();
     
    var http = require('http');
     
    http.createServer(function(request, response) {
      response.writeHead(200, {'Content-Type': 'text/plain'});
      response.end('Hello World\n');
    }).listen(process.env.PORT, process.env.IP);
     
    console.log('==> Server running at http://' + process.env.IP + ':' + process.env.PORT + '/');

  • Asynchronous Example

    require('assert-dotenv')(function(error) {
      if(error) throw error;
     
      var http = require('http');
     
      http.createServer(function (request, response) {
        response.writeHead(200, {'Content-Type': 'text/plain'});
        response.end('Hello World\n');
      }).listen(process.env.PORT, process.env.IP);
     
      console.log('==> Server running at http://' + process.env.IP + ':' + process.env.PORT + '/');
    });

• Start the server and see that all is well

  $ node ~/app/index.js
  ==> Server running at http://127.0.0.1:1337/

LICENSE

ISC License (ISC)

Copyright © 2014-2015, Buster Collings

Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.