Can't pipe object from S3 in node.js-CodePudding

I'm trying to get a file from AWS S3 and pipe it to the Express response.

My current code:

  async getMedia(key) {
    const data = await s3.getObject(
      {
        Bucket: process.env.AWS_BUCKET_NAME,
        Key: key,
      },
      (err, data) => {
        if (err) {
          throw err;
        } else data;
      }
    );
    return data;
  }

router.get('/:path/:key', async (req, res, next) => {
  try {
    const key = req.params.key;
    const path = req.params.path;
    fileService.getMedia(`${path}/${key}`).createReadStream().pipe(res);
  } catch (error) {
    next(error);
  }
});

It is throwing this error: TypeError: fileService.getMedia(...).createReadStream is not a function

I've already tried piping data.Body, data.body, but both were undefined. Can somebody tell me what's the problem right here?

CodePudding user response：

don't know about AWS S3, but the following syntax is strange:

const data = await s3.getObject(
  ...,
  (err, data) => {
    if (err) {
      throw err;
    } else data; // you're missing a return here, aren't you ?
  }
);

return data;

You're passing a callback with your (err, data) => {} function, which is a way to work without promises. In the same time, you're using async/await which is a way to work with promises : you should pick one.

Considering the callbacks are your way, your code could become :

getMedia(key, callback) {
  s3.getObject(
    {
      Bucket: process.env.AWS_BUCKET_NAME,
      Key: key,
    },
    callback,
  );
}

router.get('/:path/:key', (req, res, next) => {
  const key = req.params.key;
  const path = req.params.path;
  fileService.getMedia(
    `${path}/${key}`,
    (err, data) => {
      if (err) {
        next(err);
      } else {
        data.createReadStream().pipe(res);
      }
    }
 );
});

Considering the promises are your way, the code could be (indeed awaiting for getMedia) :

async getMedia(key) {
  const data = await s3.getObject(
    {
      Bucket: process.env.AWS_BUCKET_NAME,
      Key: key,
    }
  );

  return data;
}

router.get('/:path/:key', async (req, res, next) => {
  try {
    const key = req.params.key;
    const path = req.params.path;

    const media = await fileService.getMedia(`${path}/${key}`);

    media.createReadStream().pipe(res);
  } catch (error) {
    next(error);
  }
});

CodePudding user response：

Thanks to @LawrenceCherone, forgot to add await for fileService.getMedia