AWS S3 同步上传文件

Question

I am using Meteor on Server side where I used Method Calls to return data.

So there I am trying to upload file to AWS S3 Bucket synchronously.

Here is a sample code:

Meteor.methods({

    uploadImage: function (params) {

        var AWS = Npm.require('aws-sdk');

        AWS.config.loadFromPath(process.env["PWD"]+'/private/awss3/s3_config.json');
        var s3Bucket = new AWS.S3( { params: {Bucket: 'users-profile-pictures'} } );

        buf = Buffer.from(params.baseimage.replace(/^data:image\/\w+;base64,/, ""),'base64')
        var data = {
          Key: params.fileName, 
          Body: buf,
          ContentEncoding: 'base64',
          ContentType: 'image/jpeg'
        };

        s3Bucket.putObject(data, function(err, data){
            if (err) { 
              console.log(err);
              console.log('Error uploading data: ', data); 
            } else {
              console.dir(data);
              console.log('successfully uploaded the image!');
            }
        });

        return data;
    },
});

Now here I want to return the response I got from AWS SDK Callback. How can I make this upload synchronously?

Answer 1

I'm not expert with AWS SDK, but for my experience, all internet requests are asyncronous, because server take time to respond. Anyway, you need to use it as you are currently using, or you need to do all your script asyncronous and then add the await tag to await the function output: await s3Bucket.putObject(... .

Answer 2

In Meteor you use wrapAsync to make async calls sync:

const putObjectSync = Meteor.wrapAsync(s3Bucket.putObject);

Meteor.methods({
  uploadImage: function (params) {
  
    var AWS = Npm.require('aws-sdk');
    
    AWS.config.loadFromPath(process.env["PWD"]+'/private/awss3/s3_config.json');
    var s3Bucket = new AWS.S3( { params: {Bucket: 'users-profile-pictures'} } );
    
    buf = Buffer.from(params.baseimage.replace(/^data:image\/\w+;base64,/, ""),'base64')
    var data = {
      Key: params.fileName, 
      Body: buf,
      ContentEncoding: 'base64',
      ContentType: 'image/jpeg'
    };
    
    const result = putObjectSync(data); 
    // Note that errors will throw an exception, which is what you want, as
    // they are handled by Meteor, letting the method called know that something
    // went wrong.

    return result;
  },
});