@backstage/config

What is @backstage/config?

@backstage/config is a configuration management library designed for use with Backstage, a platform for building developer portals. It provides a structured way to manage and access configuration data, supporting features like environment variable substitution, schema validation, and hierarchical configuration.

What are @backstage/config's main functionalities?

Loading Configuration

This feature allows you to load configuration data into a ConfigReader instance, which can then be used to access configuration values using a path-like syntax.

const { ConfigReader } = require('@backstage/config');
const config = new ConfigReader({
  app: {
    title: 'My App',
    port: 3000
  }
});
console.log(config.getString('app.title')); // Outputs: 'My App'

Environment Variable Substitution

This feature allows you to use environment variables within your configuration files, enabling dynamic configuration based on the environment.

const { ConfigReader } = require('@backstage/config');
process.env.APP_PORT = '4000';
const config = new ConfigReader({
  app: {
    port: '${APP_PORT}'
  }
});
console.log(config.getNumber('app.port')); // Outputs: 4000

Schema Validation

This feature allows you to define a schema for your configuration and validate the configuration data against this schema, ensuring that the configuration is structured and typed correctly.

const { ConfigReader, ConfigSchema } = require('@backstage/config');
const schema = ConfigSchema.object({
  app: ConfigSchema.object({
    title: ConfigSchema.string(),
    port: ConfigSchema.number()
  })
});
const config = new ConfigReader({
  app: {
    title: 'My App',
    port: 3000
  }
});
schema.validate(config); // Validates the configuration against the schema

Other packages similar to @backstage/config

config

The 'config' package is a popular Node.js configuration management library that supports hierarchical configurations, environment variable overrides, and multiple configuration file formats. It is similar to @backstage/config in its ability to manage complex configurations but does not provide built-in schema validation.

dotenv

The 'dotenv' package is a zero-dependency module that loads environment variables from a .env file into process.env. While it is simpler and more focused on environment variable management compared to @backstage/config, it lacks the hierarchical and schema validation features.

convict

The 'convict' package provides a way to define a schema for configuration files, similar to @backstage/config. It supports environment variable overrides and validation, making it a close alternative for applications that require schema validation and structured configuration management.

README

@backstage/config

This package provides a config API used by Backstage core, backend, and CLI.

Installation

Do not install this package directly, it is an internal package used by @backstage/core, @backstage/cli, and @backstage/backend-common. Depend on either of those instead.

Documentation

• Backstage Readme
• Backstage Documentation