Config from schema

A tool for building an application object from config files, command line arguments, or environment variables based on an OpenAPI compatible schema definition.

Config schema

Config schema format is defined in the OpenAPI Config Extension Specification.

Features

• Type coercion
• Schema validation
• Command line interface

Usage

1. Install

   yarn add config-from-schema
   

2. Create schema

   // schema.js
   const schema = {
     'x-config': [
        {
          name: 'port',
          description: 'Application port',
          default: 3000,
          schema: {
            type: 'integer'
          }
        },
        {
          name: 'secret',
          description: 'Secret used for signing session cookies',
          required: true,
          schema: {
            type: 'string'
          }
        }
     ]
   }
   
   export default schema
   

3. Build config

   // app.js
   import schema from './schema'
   import configFromSchema from 'config-from-schema'
   
   const config = configFromSchema('foo', schema)
   
   console.info(config.port, config.secret)
   

4. Run app

   Provide values via CLI args

   $ node app --secret foo
   3000 'foo'
   

   OR via environment variables

   FOO_SECRET=bar node app
   3000 'bar'
   

   OR via a config file

   cat ~/.sso.json | jq .

   $ cat ~/.foo.json
   {
     "secret": "baz"
   }
   $ node app
   3000 'baz'
   

5. View docs

   $ node app --help
   Usage: app [options]
   
   Options:
     --help    Show help                                                  [boolean]
     --config  Path to config file
                                 [string] [default: "~/.foo.json"]
     --port    Application port                                     [default: 3000]
     --secret  Secret used for signing session cookies          [string] [required]