Set-cookie headers are not being sent when calls are made through apollo federation gateway NestJs

Question

I have a non monorepo nestJs graphql microservices app, and opted for Apollo federation gateway. I have an authentication server which works fine and sets cookies to header, only problem is when calls are made through apollo gateway set-cookie headers are not being set, and request headers cookies are not passed to microservices.

this is my gatewayModule

@Module({
  imports: [
    GraphQLModule.forRoot<ApolloGatewayDriverConfig>({
      driver: ApolloGatewayDriver,
      gateway: {
        supergraphSdl: new IntrospectAndCompose({
          subgraphs: [
            {
              name: 'users',
              url: 'http://localhost:9999/graphql',
            },
            {
              name: 'posts',
              url: 'http://localhost:9119/graphql',
            },
            {
              name: 'comments',
              url: 'http://localhost:9229/graphql',
            },
          ],
        }),
      },
    }),
  ],
}) 

Answer 1

I have found a solution, add the following class and import it to app.module

// graphql-data-source.ts
import {
  GraphQLDataSourceProcessOptions,
  RemoteGraphQLDataSource,
} from '@apollo/gateway';
import { GraphQLDataSourceRequestKind } from '@apollo/gateway/dist/datasources/types';

export class GraphQLDataSource extends RemoteGraphQLDataSource {
  didReceiveResponse({ response, context }): typeof response {
    const cookies = response.http.headers?.raw()['set-cookie'] as
      | string[]
      | null;

    if (cookies) {
      context?.req.res.append('set-cookie', cookies);
    }

    return response;
  }

  willSendRequest(params: GraphQLDataSourceProcessOptions) {
    const { request, kind } = params;

    if (kind === GraphQLDataSourceRequestKind.INCOMING_OPERATION) {
      const cookie =
        params?.incomingRequestContext.request.http.headers.get('Cookie');
      request.http.headers.set('Cookie', cookie);
    }
  }
}

then edit app.module

....
 GraphQLModule.forRoot<ApolloGatewayDriverConfig>({
      driver: ApolloGatewayDriver,
      gateway: {
        buildService: (args) => new GraphQLDataSource(args),
        supergraphSdl: new IntrospectAndCompose({
          subgraphs: [
....