JwtModule.registerAsync not working in NestJS

Question

I'm working on a NestJS project and I need to use JWT with .env configuration. It generates the token but when trying to access the secured url(With Authorization header), it just returns the Unauthorized message.

jwt.strategy.ts

import { Injectable, UnauthorizedException, Logger } from '@nestjs/common';
import { PassportStrategy } from '@nestjs/passport';
import { ExtractJwt, Strategy } from 'passport-jwt';
import { AuthService } from './auth.service';
import { JwtPayload } from './interfaces/jwt-payload.interface';

@Injectable()
export class JwtStrategy extends PassportStrategy(Strategy) {

    constructor(private readonly authService: AuthService) {
        super({
            jwtFromRequest: ExtractJwt.fromAuthHeaderAsBearerToken(),
            secretOrKey: process.env.JWT_SECRET_KEY,
        });
    }

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

        return user;
    }
}

auth.module.ts

import { Module } from '@nestjs/common';
import { AuthService } from './auth.service';
import { AuthController } from './auth.controller';
import { PassportModule } from '@nestjs/passport';
import { JwtModule } from '@nestjs/jwt';
import { JwtStrategy } from './jwt.strategy';

@Module({
  imports: [
    PassportModule.register({ defaultStrategy: 'jwt' }),
    JwtModule.registerAsync({
      useFactory: async () => ({
        secretOrPrivateKey: process.env.JWT_SECRET_KEY,
        signOptions: {
          expiresIn: process.env.JWT_EXPIRATION_TIME,
        },
      }),
    }),
  ],
  providers: [AuthService, JwtStrategy],
  controllers: [AuthController],
})
export class AuthModule {}

main.ts

import { NestFactory } from '@nestjs/core';
import * as dotenv from 'dotenv';
import { ApiModule } from './api/api.module';
import { Logger } from '@nestjs/common';

async function bootstrap() {
  dotenv.config({ path: './.env'});
  const app = await NestFactory.create(ApiModule);
  const port = process.env.APP_PORT;

  await app.listen(port);
  Logger.log(`Server started on http://localhost:${port}`);
}
bootstrap();

Looks like JwtModule.registerAsync is not working with environment variables. I've tried many things but it always fails. If I change environment variables in auth.module.ts for static data, then it works fine. Something like this:

secretOrPrivateKey: 'secretKey',
signOptions: {
  expiresIn: 3600,
},

UPDATE Project structure

- src
    - api
        - auth
            - interfaces
                jwt-payload.interface.ts
            auth.controller.ts
            auth.module.ts
            auth.service.ts
            jwt.strategy.ts
            index.ts
        api.module.ts
        index.ts
    main.ts
- test
.env

My main.ts looks like this now.

import { NestFactory } from '@nestjs/core';
import * as dotenv from 'dotenv';
import { resolve } from 'path';
import { ApiModule } from './api/api.module';
import { Logger } from '@nestjs/common';

async function bootstrap() {
  dotenv.config({ path: resolve(__dirname, '../.env') });
  const app = await NestFactory.create(ApiModule);
  const port = process.env.APP_PORT;

  await app.listen(port);
  Logger.log(`Server started on http://localhost:${port}`);
}
bootstrap();

You see that my .env is in the root of the project.

Answer 1

If you use config module you can do something like this:

JwtModule.registerAsync({
  useFactory: (config: ConfigService) => {
    return {
      secret: config.get<string>('JWT_SECRET_KEY'),
      signOptions: {
        expiresIn: config.get<string | number>('JWT_EXPIRATION_TIME'),
      },
    };
  },
  inject: [ConfigService],
}),

I also had a problem with initializing JwtModule and this code solved it.