Runtime settings

This projects uses the config library. In a nutshell, configuration variables are defined in environment specific files under the config folder and certain values can be overriden using environment variables.

See the official documentation on Configuration files for more detals on configuration override logic and config files interpretation ordering.

Example usage:

somecode.ts

import config from 'config';

// config get can either be used to retrieve a single value
const port = config.get<string>('restApi.port');

// ...or a full object
const dbOptions = config.get<object>('mongodb.options');

Configuration files

tip

In order to quiclky override settings while developping you can use config/local-development.yaml.

Note: This file should not be versionned as it may be different for each developper and can possibly contain secrets for debugging purposes (it is already gitignored, but it's worth being aware of that).

The following files are used:

• config/
  • default.yaml: base configuration.
  • development.yaml: overrides config values for development.
  • production.yaml: overrides config values for production. Don't put any sensitive data here. Prever environment variables instead.
  • test.yaml: used when running tests.
  • local-development.yaml: (optional) use this to override values for your local development enviromnent. This file should not be commited.
  • loca-test.yaml: (optional) use this to override values for your local test enviromnent. This file should not be commited.

These files follow the following tree structure:

config/default.yaml

restApi:
  # The api server port
  port: '3000'
  # The base url that will be used to form absolute urls
  baseUrl: 'http://localhost'
# The least significant level of logs that should be emitted.
logLevel: 'info'
# OpenAPI base documentation infos
openAPI:
  # You application title.
  # If absent uses package.json contents (preferred).
  title: Sample Pet Store App
  # API version. You can use semantic versioning like 1.0.0, 
  # or an arbitrary string like 0.99-beta.
  # If absent uses package.json contents (preferred).
  version: 1.0.0 
  # API description. Arbitrary text in CommonMark or HTML.
  # If absent uses package.json contents (preferred).
  description: This is a sample server for a pet store.
  # Link to the page that describes the terms of service.
  # Must be in the URL format.
  termsOfService: http://example.com/terms/
  # Contact information: name, email, URL.
  contact:
    name: API Support
    email: support@example.com
    url: http://example.com/support
  # Name of the license and a URL to the license description.
  license:
    name: ISC
    url: https://opensource.org/license/isc-license-txt/
  # Link to the external documentation (if any).
  # Code or documentation generation tools can use description as the text of the link. 
  externalDocs:
    description: Find out more
    url: http://example.com
# Db connection settings, see https://mongoosejs.com/docs/connections.html#options for more details.
mongodb:
  host: mongodb://localhost:27017/default
  options:
    useUnifiedTopology: 'true'
    connectTimeoutMS: 1000
    serverSelectionTimeoutMS: 5000
    keepAlive: true

Environment variables

Available environment variables

varialbe	development defaults	overrides	description
PORT	3000	restApi.port	The port that the server will listen to.
baseUrl	http://localhost	restApi.baseUrl	Base url to be used when building absolute Urls`
logLevel	info	logLevel	Defines the log level that will be emitted.
mongoDbHost	mongodb://localhost:27017/dev	mongodb.host	MongoDb connection string

Examples:

Increase the log verbosity for a development run

logLevel=debug npm run watch

Runs the production server on the 4242 port

PORT=4242 npm run prod

Exposing environment variables

Accepted environment variables are defined in config/custom-envirnment-variables.yaml. For every path in the configuration tree structure you can specify the environment variable that will be used as input.

config/custom-envirnment-variables.yaml

restApi:
  port: 'PORT'
  baseUrl: 'baseUrl'
logLevel: 'logLevel'
mongodb:
  host: 'mongoDbHost'