Drop requirements for aws-sdk data and dirname

[simonfan]

As aws-sdk auto-loads configurations and credentials from ~/.aws/ directory and the recommended way of loading credentials is by letting the aws-sdk do so, I suggest we drop the requirements for the region, secretAccessKey and accessKeyId.

The dirname option also should not be required, as it is not mandatory to upload the file to a directory (though useful for most cases).

What do you think?

  if (!opts.secretAccessKey) throw new Error('secretAccessKey is required')
  if (!opts.accessKeyId) throw new Error('accessKeyId is required')
  if (!opts.region) throw new Error('region is required')
  if (!opts.dirname) throw new Error('dirname is required')

[anacronw]

I think I agree with the dirname being optional.

On the other hand, aws-sdk might have that behavior, but I don't see a reason why that should be necessarily followed. So as long as the required options are called out explicitly, I'm fine with it :)

[LinusU]

Another way to go would be to let the user provide the aws object. I haven't really thought this thru and I'm not saying it's the way to go, but it could be interesting exploring how the api would look then.

[LinusU]

e.g.

var express = require('express')
var multer = require('multer')
var aws = require('aws-sdk')
var multerS3 = require('multer-s3')

var app = express()
var s3 = new aws.S3({ bucket: 'storage' })
var storage = multerS3(s3, function (req, file, cb) {
  cb(null, 'photos/file-' + Date.now() + '.jpg')
})
var upload = multer({ storage: storage })

app.post('/upload', upload.array('photos', 3), function (req, res, next) {
  res.send('Successfully uploaded!')
})

This way the s3 object can also be used outside of this module, for querying and manipulating the files that where uploaded. It would also drop the dependency of aws-sdk from this module...

[LinusU]

I also think that we should prefer the terminology Key over dirname and filename since that is what amazon calls it. As shown in another issue, calling it dirname has caused some confusion...

[anacronw]

yeah you're right, it should be key instead of dirname. I think I was trying to follow the options on multer.

[simonfan]

I personally like the idea of letting the user provide the s3 object. That way the multer storage engine does not interfere with the rest of the application.

[anacronw]

I'm OK with it either way. Maybe this also gives the user some more control over their configuration.

[anacronw]

Not relevant now b/c it'll just accept s3 options.

Please checkout version 1.5.0