@sorodriguez/config-client v1.0.0

Config Client

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A lightweight client for loading configuration from a Config Server. This library is built with TypeScript and provides seamless integration with NestJS applications, but can also be used with plain Node.js and Express applications.

Features

• Load configuration from a Config Server
• Support for multiple repositories, applications, and profiles
• Basic authentication support
• Automatic environment variable population
• Global module for NestJS applications

Installation

npm install config-client

Built With

• TypeScript
• NestJS integration
• Axios for HTTP requests

Usage

With NestJS

Import the ConfigClientModule into your application's root module and use the forRoot method to configure it:

import { Module } from '@nestjs/common';
import { ConfigClientModule } from 'config-client';
import { AppController } from './app.controller';
import { AppService } from './app.service';

@Module({
  imports: [
    ConfigClientModule.forRoot('https://your-config-server-url/config', [
      {
        repo: 'your-config-repo',
        application: 'your-application-name',
        profile: 'dev',
        auth: {
          username: 'username',
          password: 'password'
        }
      }
    ]),
  ],
  controllers: [AppController],
  providers: [AppService],
})
export class AppModule {}

You can then inject the configuration values using the @Inject decorator:

import { Injectable, Inject } from '@nestjs/common';

@Injectable()
export class AppService {
  constructor(@Inject('CONFIG_VALUES') private readonly config: Record<string, any>) {}

  getConfig(key: string): any {
    return this.config[key];
  }
}

With TypeScript (non-NestJS)

You can use the module with plain TypeScript as well:

import { ConfigClientModule } from 'config-client';

async function loadConfig() {
  const configModule = ConfigClientModule.forRoot('https://your-config-server-url/config', [
    {
      repo: 'your-config-repo',
      application: 'your-application-name',
      profile: 'dev',
      auth: {
        username: 'username',
        password: 'password'
      }
    }
  ]);

  // Manually invoke the factory function
  const configProvider = configModule.providers.find(p => p.provide === 'CONFIG_VALUES');
  await configProvider.useFactory();

  // Now your configuration is loaded in process.env
  console.log(`Database URL: ${process.env.DATABASE_URL}`);
}

loadConfig().catch(console.error);

With JavaScript (Node.js/Express)

const { ConfigClientModule } = require('config-client');
const express = require('express');
const app = express();

async function bootstrap() {
  try {
    // Configure the config client
    const configModule = ConfigClientModule.forRoot('https://your-config-server-url/config', [
      {
        repo: 'your-config-repo',
        application: 'your-application-name',
        profile: 'dev',
        auth: {
          username: 'username',
          password: 'password'
        }
      }
    ]);

    // Manually invoke the factory function
    const configProvider = configModule.providers.find(p => p.provide === 'CONFIG_VALUES');
    await configProvider.useFactory();

    // Start your Express app
    app.get('/', (req, res) => {
      res.send('Configuration loaded successfully!');
    });

    const port = process.env.PORT || 3000;
    app.listen(port, () => {
      console.log(`Server running at http://localhost:${port}`);
    });
  } catch (error) {
    console.error('Failed to load configuration:', error);
    process.exit(1);
  }
}

bootstrap();

Multiple Connections

You can connect to multiple repositories, applications, or profiles by providing an array of configuration options:

ConfigClientModule.forRoot('https://your-config-server-url/config', [
  // First configuration
  {
    repo: 'main-config-repo',
    application: 'api-service',
    profile: 'dev',
    auth: {
      username: 'username1',
      password: 'password1'
    }
  },
  // Second configuration
  {
    repo: 'shared-config-repo',
    application: 'common',
    profile: 'prod',
    auth: {
      username: 'username2',
      password: 'password2'
    }
  }
])

This will load configuration from both sources and merge them into a single configuration object. If there are duplicate keys, the first one encountered will be used for environment variables.

Connecting to Different Config Servers

If you need to connect to multiple config servers, you can create separate instances of the ConfigClientModule:

import { Module } from '@nestjs/common';
import { ConfigClientModule } from 'config-client';

@Module({
  imports: [
    // Primary config server
    ConfigClientModule.forRoot('https://primary-config-server/config', [
      {
        repo: 'primary-repo',
        application: 'your-app',
        profile: 'dev'
      }
    ]),
    // Secondary config server
    ConfigClientModule.forRoot('https://primary-config-server/config', [
      {
        repo: 'primary-repo',
        application: 'your-app',
        profile: 'prod'
      }
    ]),
  ],
})
export class AppModule {}

API Reference

ConfigClientModule

forRoot(url: string, options: ConfigClientOptions[]): DynamicModule

Creates and configures the ConfigClientModule.

• url: The URL of the Config Server
• options: An array of configuration options

ConfigClientOptions

• repo: The name of the repository
• application: The name of the application
• profile: The profile to use (e.g., 'dev', 'prod')
• auth: (Optional) Authentication credentials
  • username: Username for basic authentication
  • password: Password for basic authentication

License

ISC