Verify if my node.js instance is dev or production

Normally you should run a node app in production like this:

NODE_ENV=production node app.js

Applications with Express, Socket.IO and other use process.env.NODE_ENV to figure out the environment.

In development you can omit that and just run the app normally with node app.js.

You can detect the environment in your code like this:

var env = process.env.NODE_ENV || 'development';
loadConfigFile(env + '.json', doStuff);

Resources:

How do you detect the environment in an express.js app?

I think the easiest way to set the environment is to pass command-line argument to your application.

node ./server.js dev

In your script you need to handle this argument and set configuration what you need for it.

var env = process.argv[2] || 'dev';
switch (env) {
    case 'dev':
        // Setup development config
        break;
    case 'prod':
        // Setup production config
        break;
}

Also, i was created module that makes the configuration process a bit easier. Maybe it will help you.

Actually, I would not recommend to store configuration values like database connection information, passwords, access tokens and such inside of actual application code for the following reasons:

1. Hardcoding those values make it difficult to change them later on. You will have to release a new version of the application to change those values.

2. This is a serious security violation, because production-grade configuration data and passwords shouldn't be stored in code. It's very easy to leak this sensitive data.

The better approach would be to externalize this data and pass it to your application during execution. This is normally done by means of environment variables. You just need to define unique environment variable for each peace of data that needs to be changeable between different environments.

For example: DB_HOST, DB_USER, DB_PASSWORD. Then you could pass those values to you app in production this way:

$ NODE_ENV=production DB_HOST=1.2.3.4 DB_USER=someusername DB_PASSWORD=somerandompassword /bin/node app.js

Actually, this values could be encrypted and added to the codebase and then decrypted during the deployment. However, make sure that decryption key is stored securely in deployment system or provided interactively by the release engineer. Shippable allows to do this out of the box.

In the development environment it gets simpler, because you can use very convenient dotenv module. Just create a .env file in your project's root directory and add all variables to it:

DB_HOST=1.2.3.4
DB_USER=someusername
DB_PASSWORD=somerandompassword

But, make sure to exclude it from you VCS, because each developer probably would want to have personal configuration. You can create a .env.dist file to contain default configuration, which later could be used as a template: cp .env.dist .env.