@showroomprive/azure-appconfig

A library to use Azure App Configuration in NestJS.

It will decompose Azure App Configuration Data into an interface.

Table of Contents

• @showroomprive/azure-appconfig
• Table of Contents
  • Requirements
  • Dependencies
    • Dev Dependencies
    • Peer Dependencies
  • Data Description
  • Installation
  • Configuration
    • app.module.ts
  • Usage

Requirements

To use this library, the following requirements need to be met :

| Library Name | Version | Description | |--------------------|---------|-----------------------------------------------------------------------------| | @nestjs/common | ^10.4.8 | Common utilities used by NestJS applications. | | @nestjs/core | ^10.0.0 | The core package of the NestJS framework. | | rxjs | ^7.8.1 | A library for reactive programming using Observables, to make it easier to compose asynchronous or callback-based code. | | @nestjs/config | ^3.3.0 | A module for managing application configuration in NestJS. |

Dependencies

| Dependency | Version | |-----------------------------|----------| | @nestjs/common | ^11.0.11 | | @azure/app-configuration | ^1.8.0 | | @azure/identity | ^4.7.0 | | @azure/keyvault-secrets | ^4.9.0 | | @nestjs/config | ^4.0.1 | | @nestjs/core | ^11.0.11 | | rxjs | ^7.8.2 |

Dev Dependencies

| Dependency | Version | |-----------------------------|----------| | @types/node | ^22.13.9 | | typescript | ^5.8.2 |

Peer Dependencies

| Dependency | Version | |-----------------------------|----------| | @nestjs/common | ^11.0.11 | | @nestjs/core | ^11.0.11 | | rxjs | ^7.8.2 | | @nestjs/config | ^4.0.1 |

Data Description

The data is described like this :

export interface ApplicationSettings<T> {
    [key: string]: T | GeneralSettings;
    General: GeneralSettings;
    Application: T;
}

General property will have all data that can be used by any application, his prefix in Azure App Configuration is : SRP.

Application property is a configuration that will be unique for each application, his prefix in Azure App Configuration is equals to the value of APP_CONFIG_NAME environnement variable.

Installation

To install the package, run:

npm install @showroomprive/azure-appconfig

Configuration

To use the library, several environment variables need to be provided in a .env file at the root:

| Variable Name | Description | |-------------------|--------------------------------------------------| | APP_CONFIG_URL | The URL of the Azure App Configuration instance. | | ENVIRONMENT | The current environment (e.g., dev, prod, test, local). | | APP_CONFIG_NAME | The name of the Azure App Configuration prefix. |

For local developpement, the variable ENVIRONMENT is mandatory, we won't reach the Azure App Configuration, we use a json file that is parsed instead.

The configuration is splitted in 2 parts :

• General part (prefix in Azure App Configuration : SRP)
• Application part (prefix in Azure App Configuration: value of APP_CONFIG_NAME environnement variable)

The local configuration should be at the root of the project (near package.json and .env files):

The file should be named : local.config.json :

{
    "SampleSettings": {
        "SampleSetting1": "Value1",
        "SampleSetting2": "Value2"
    },
    "SRP": {
        "InternalBasePaths": {
            "BetaWebApp": "/beta/webapp"
        }
    }
}

Warning: This file may contain sensitive information. Ensure it is not committed to version control and is kept local to your development environment.

app.module.ts

We need imports 2 modules:

• ConfigModule (global way to share configuration through the whole application)
• AzureAppconfigModule

We need to add one provider to access the data :

• ApplicationSettingsService

So the changes will be like that :

import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { ConfigModule } from '@nestjs/config';
import { ApplicationSettingsService, AzureAppconfigModule } from '@showroomprive/azure-appconfig';
import { azureAppconfigLoader } from "@showroomprive/azure-appconfig/dist/azure-appconfig-loader";

@Module({
  imports: [
    ConfigModule.forRoot({ isGlobal: true,
        load: [
          azureAppconfigLoader
        ],
     }),
    AzureAppconfigModule],
  controllers: [AppController],
  providers: [ ApplicationSettingsService],
})
export class AppModule {}

Usage

To access the data we need to use Dependency injection for the ApplicationSettingsService and then we will be able to access the General and Application properties.

For example :

import { Controller, Get } from '@nestjs/common';
import { ApplicationSettingsService } from '@showroomprive/azure-appconfig';
import { SampleSettings } from './models/sample-settings';
import { GeneralSettings } from '@showroomprive/azure-appconfig/dist/models/general-settings';

@Controller()
export class AppController {

  constructor(private readonly azureAppConfiguration: ApplicationSettingsService<SampleSettings>) {
  }

  @Get("general")
  getGeneralSettings(): GeneralSettings | undefined {
    return this.azureAppConfiguration.General;
  }

  @Get("application")
  getApplicationSettings(): SampleSettings | undefined {
    return this.azureAppConfiguration.Application;
  }
}

Where SampleSettings is an interface :

export interface SampleSettings {
    SampleSetting1: string;
    SampleSetting2: string;
}

The ApplicationSettingsService<SampleSettings> use ConfigService to get the configurations and configure 2 properties, General and Application :

these 2 get the values like this :

• General : configService.get<SampleSettings>('General')
• Application : configService.get<SampleSettings>('Application')

For factory, we can access the configuration on ConfigService from @nestjs/config

There is a sample of how to do it with knex :

import { Global, Module } from '@nestjs/common';
import Knex from 'knex';
import { Model } from 'objection';
import { ConfigService } from '@nestjs/config';
import { SampleSettings } from 'src/models/sample-settings';

@Global()
@Module({
  providers: [   
    {
      provide: 'KnexConnection',
      useFactory: async (configService : ConfigService) => {
        const config = configService.get<SampleSettings>('Application');
        const knex = Knex({
          client: 'mssql',
          connection: {
            host: config.DatabaseSettings.Host,
            user: config.DatabaseSettings.User,
            password: config.DatabaseSettings.Password,
            database: config.DatabaseSettings.Name,
            port: Number(config.DatabaseSettings.Port),
          }
        });
        Model.knex(knex);
        return knex;
      },
      inject: [ConfigService],
    },
  ],
  exports: ['KnexConnection'],
})
export class DatabaseModule {}