A NestJS module for managing environment variables easily and securely.
- Decentralizes environment variables by managing each as a provider
- Protects changing values of environment variable by developer's mistake
- Supports strong validation
- Supports type inference
- Supports modifying environment variables at runtime via remote config(such as Apache ZooKeeper etc).
# npm
npm install @nestjs-library/config
# yarn
yarn add @nestjs-library/config
# pnpm
pnpm add @nestjs-library/configIn @nestjs-library/config, each environment variable is managed by a provider. So, you should create a config service first.
We use class-transformer internally for transforming environment variables to Config Class. You can use decorators such as @Expose and @Type as your need.
// database-config.service.ts
import { Injectable } from '@nestjs/common';
import { AbstractConfigService } from '@nestjs-library/config';
import { Expose, Type } from 'class-transformer';
@Injectable()
export class DatabaseConfigService extends AbstractConfigService<DatabaseConfigService> {
@Expose({ name: 'DATABASE_HOST' })
host: string;
@Expose({ name: 'DATABASE_PORT' })
@Type(() => Number)
port: number;
@Expose({ name: 'DATABASE_PASSWORD' })
password: string;
}You can use decorators from class-validator for validation and @Transform() decorator of class-transformer for providing default value.
// database-config.service.ts
import { Injectable } from '@nestjs/common';
import { AbstractConfigService } from '@nestjs-library/config';
import { Expose, Transform, Type } from 'class-transformer';
import { IsNotEmpty, IsPositive, IsString } from 'class-validator';
@Injectable()
export class DatabaseConfigService extends AbstractConfigService<DatabaseConfigService> {
@Expose({ name: 'DATABASE_HOST' })
@Transform(({ value }) => value ?? 'localhost')
@IsString()
@IsNotEmpty()
host: string;
@Expose({ name: 'DATABASE_PORT' })
@Type(() => Number)
@Transform(({ value }) => value ?? 5532)
@IsPositive()
port: number;
@Expose({ name: 'DATABASE_PASSWORD' })
@Transform(({ value }) => value ?? 'local')
@IsString()
@IsNotEmpty()
password: string;
}// test.module.ts
import { Module } from '@nestjs/common';
import { ConfigModule } from '@nestjs-library/config';
import { DatabaseConfigService } from './database-config.service';
import { TestService } from './test.service';
@Module({
imports: [ConfigModule.forFeature(DatabaseConfigService)],
providers: [TestService],
exports: [TestService,]
})
export class TestModule {}// test.service.ts
import { Injectable } from '@nestjs/common';
import { DatabaseConfigService } from './database-config.service';
@Injectable()
export class TestService {
constructor(private readonly databaseConfigService: DatabaseConfigService) {}
getDatabaseConfig() {
return this.databaseConfigService;
}
}(To be added)
This library is licensed under the MIT License. See the LICENSE file for details.