rconf

An easy-to-use, powerful configuration package.

Features

• Loading values from files
• Passing values as command-line arguments
• Automatically generating --help text
• A configuration file to define the configuration of your configuration.

Usage

In the root of your project, create a folder named config, and create a file named _opts.json inside it. This file will contain the names, descriptions, and default values of your config options. The file should be formatted like this:

{
    /* Name:   [ Description,                         Flag,   Type,     Default value */
    "address": ["The address to deliver the cake to",  "-a", "string", "123 Cakewalk Lane"],
    "slices":  ["How many slices of cake are needed",  "-s", "number", 3]
}

Now you can load the config in your code like so:

var config = require('rconf');
 
console.log('Delivering ' + config.slices + ' slices of cake to ' + config.address);

And now you can run it in the console

$ node cakedelivery.js
Delivering 3 slices of cake to 123 Cakewalk Lane

$ node cakedelivery.js --slices 7436
Delivering 7436 slices of cake to 123 Cakewalk Lane

$ node cakedelivery.js -a "456 Pastry Drive"
Delivering 3 slices of cake to 456 Pastry Drive

Rconf will also generate a help message

$ node cakedelivery.js --help
    --address  -a  ['123 Cakewalk Lane'] The address to deliver the cake to
    --slices   -s  [3]                   How many slices of cake are needed

Configuration files

Rconf can also load config values from files. By default, it tries to load values from config/local.json and config/$NODE_ENV.json. To test this, create the config/local.json file and format it like so:

{
    "address": "789 Frosting Road",
    "slices": 5
}

These values will now override the default values set in _opts.json, but will be overridden by command-line arguments.

Rconf also loads a file for the current NODE_ENV. For instance, if the NODE_ENV is set to "production", config/production.json will be loaded. The values in production.json override local.json and _opts.json, but are still overridden by command-line arguments.

Hidden values

When you run your script with the --help option, it will display the preset values for each option. However, some values may need to be kept secret (API keys, database passwords, etc.). To hide these values, add a fifth element to the end of the option's array in _opts.json, set to true.

    "address": ["The address to deliver the cake to",      "-a", "string", "123 Cakewalk Lane"],
    "slices":  ["How many slices of cake are needed",      "-s", "number", 3]
    "recipe":  ["The secret recipe used to make the cake", "-r", "string", "", true] // Note the extra value

Now, any values set in the configuration files for recipe will be redacted in the help text, like so:

$ node cakedelivery.js --help
    --address  -a  ['123 Cakewalk Lane'] The address to deliver the cake to
    --slices   -s  [3]                   How many slices of cake are needed
    --recipe   -r  [hidden]              The secret recipe used to make the cake