config-dug

Config Dug

Config Management library for Node.js

Major features

• Strongly typed config object
• Specify config schema with Zod
  • Support for many data types including: string, number, boolean, array, object, enum, date and more
• Plugin support with included plugins for AWS Secrets Manager and AWS AppConfig
  • Live reloading of config values from plugins
• Compatible with dependency injection frameworks like tsyringe and InversifyJS
• Support for CJS and ESM projects

Usage

Installing

npm install config-dug

Basic Usage

import { ConfigDug, z } from 'config-dug';

const schema = {
  logLevel: z.string().default('info'),
};

const config = await ConfigDug.getConfig(schema);

Advanced Usage

import { ConfigDug, z } from 'config-dug';
import { AWSSecretsManagerPlugin } from '@config-dug/plugin-aws-secrets-manager';

const schema = {
  logLevel: z.string().default('info'),
  apiToken: {
    schema: z.string(),
    sensitive: true,
  },
};

const awsSecretsManagerPlugin = new AWSSecretsManagerPlugin({
  secrets: [
    {
      name: 'config-dug-test/config',
      region: 'ca-central-1',
      reloadInterval: '1m',
    },
  ],
});

const configDug = new ConfigDug(schema, { plugins: [awsSecretsManagerPlugin] });

configDug.on('config-loaded', (config) => {
  console.log('config-loaded event received', config);
});

configDug.on('config-reloaded', (config) => {
  console.log('config-reloaded event received', config);
});

await configDug.load();

const getConfig = () => {
  return configDug.getConfig();
};

export { getConfig };

Options

Name	Type	Default	Description
basePath	string	process.cwd()	The directory to load config files from
envKey	string	APP_ENV	The environment variable specifying the application environment
loadConfigFiles	boolean	true	Load config values from `config.*.{js
loadEnvironment	boolean	true	Load config values from the environment
plugins		[]	An array of plugins to load. Plugins are evaluated in order so config values that come from a plugin that is specified later will override config values from plugins specified earlier
printConfig	boolean	false	Print the resolved config when loaded
strict	boolean	false	When false config values are preprocessed first to coerce them to the specified type
warnOnLocalConfigFile	boolean	true	Print a warning when a local config file `config.*.local.{js

Plugins

• TODO: Add instructions on using plugins
• TODO: Add a guide on writing plugins

Plugin Interface

interface ConfigDugPlugin {
  public load(): Promise<UntypedConfig>;
  public reload(): Promise<UntypedConfig>;
}

Plugin Return Value

{
  values: UntypedConfig, // Record<string, unknown>
  valueOrigins: ValueOrigins, // Record<string, string[]>
  nextReloadIn: number | undefined
}

Plugin Lifecycle

flowchart TB
    A[Initialize] --> B
    B[onBeforeLoadConfigFiles] --> C
    C[loadConfigFiles] --> D
    D[onAfterLoadConfigFiles] --> E
    E[onBeforeLoadPlugins] --> F
    F[loadPlugins] --> G
    G[onAfterLoadPlugins] --> H
    H[onBeforeLoadLocalConfigFiles] --> I
    I[loadLocalConfigFiles] --> J
    J[onAfterLoadLocalConfigFiles] --> K
    K[onBeforeLoadEnvironment] --> L
    L[loadEnvironment] --> M
    M[onAfterLoadEnvironment]

Contributing

TODO: Add CONTRIBUTING.md

Credits

v2 was inspired by Zod and znv

v1 was inspired by config3 and config4

License

MIT