nest-http-proxy

A Nest module wrapper for http-proxy-middleware

Installation

To begin using it, we first install the required dependencies.

$ npm install --save nest-http-proxy http-proxy-middleware

Getting started

Once the installation is complete, import the HttpProxyModule into the root AppModule and run the forRoot() static method as shown below:

import { Module } from '@nestjs/common';
import { HttpProxyModule } from 'nest-http-proxy';

@Module({
  imports: [
    HttpProxyModule.forRoot({
      '/api': {
        target: 'http://www.example.org/api',
        changeOrigin: true,
      },
    }),
  ],
})
export class AppModule {}

The forRoot() method accepts a proxy table object to create and configure proxy middlewares.

Async configuration

When you need to pass module options asynchronously instead of statically, use the forRootAsync() method. As with most dynamic modules, Nest provides several techniques to deal with async configuration.

One technique is to use a factory function:

HttpProxyModule.forRootAsync({
  useFactory: () => ({
    '/api': {
      target: 'http://www.example.org/api',
      changeOrigin: true,
    },
  }),
});

Like other factory providers, our factory function can be async and can inject dependencies through inject.

HttpProxyModule.forRootAsync({
  imports: [ConfigModule],
  useFactory: async (configService: ConfigService) => 
    configService.get('proxyTable'),
  inject: [ConfigService],
});

Alternatively, you can configure the HttpProxyModule using a class instead of a factory, as shown below.

HttpProxyModule.forRootAsync({
  useClass: HttpProxyConfigService,
});

The construction above instantiates HttpProxyConfigService inside HttpProxyModule, using it to create an options object. Note that in this example, the HttpProxyConfigService has to implement HttpProxyModuleOptionsFactory interface as shown below. The HttpProxyModule will call the createHttpProxyOptions() method on the instantiated object of the supplied class.

@Injectable()
class HttpProxyConfigService implements HttpProxyModuleOptionsFactory {
  createHttpProxyOptions(): HttpProxyModuleOptions {
    return {
      '/api': {
        target: 'http://www.example.org/api',
        changeOrigin: true,
      },
    }
  }
}

If you want to reuse an existing options provider instead of creating a private copy inside the HttpProxyModule, use the useExisting syntax.

HttpProxyModule.forRootAsync({
  imports: [ConfigModule],
  useExisting: HttpProxyConfigService,
});

License

MIT