How to get the configurations from within a module import in NestJS?

Question

Let's say I have my module defined as below:

@Module({
  imports: [
    PassportModule.register({ defaultStrategy: 'jwt' }),
    JwtModule.register({
      // Use ConfigService here
      secretOrPrivateKey: 'secretKey',
      signOptions: {
        expiresIn: 3600,
      },
    }),
    PrismaModule,
  ],
  providers: [AuthResolver, AuthService, JwtStrategy],
})
export class AuthModule {}

Now how can I get the secretKey from the ConfigService in here?

Answer 1

You have to use registerAsync , so you can inject your ConfigService . With it, you can import modules, inject providers and then use those providers in a factory function that returns the configuration object:

JwtModule.registerAsync({
  imports: [ConfigModule],
  useFactory: async (configService: ConfigService) => ({
    secretOrPrivateKey: configService.getString('SECRET_KEY'),
    signOptions: {
        expiresIn: 3600,
    },
  }),
  inject: [ConfigService],
}),

For more information, see the async options docs .

Answer 2

Or there is another solution, create an JwtStrategy class, something like this:

@Injectable()
export class JwtStrategy extends PassportStrategy(Strategy) {
    constructor(private readonly authService: AuthService) {
        super({
            jwtFromRequest: ExtractJwt.fromAuthHeaderAsBearerToken(),
            secretOrKey: config.session.secret,
            issuer: config.uuid,
            audience: config.session.domain
        });
    }

    async validate(payload: JwtPayload) {
        const user = await this.authService.validateUser(payload);
        if (!user) {
            throw new UnauthorizedException();
        }
        return user;
    }
}

There you are able to pass ConfigService as a parameter to the constructor, but I'm using config just from plain file.

Then, don't forget to place it in array of providers in module.

Regards.