Transfer file from AWS S3 to OneDrive with AWS Lambda

Question

A client of ours requested that we have copies of their files on both AWS S3 and OneDrive .

The usual MO: File is sent from an iOS application to an AWS S3 bucket. This triggers an AWS Lambda Function which attaches the file to an email and sends a copy to the client, which they again store on OneDrive . Now, we want to skip the email part and transfer the file directly to OneDrive .

All my research so far points to Zapier or CloudRail or MS Graph REST Api . The problem I'm having is that we want to transfer the file with an AWS Lambda function (Java8), automagically. Almost all the tutorials and examples on MS Graph needs a client to log in manually. Mostly client side logic. The other methods have more overhead, and we don't (unnecessarily) want to make our stack more complicated than it already is.

I realize this is a very specific case. We are systematically replacing the client's file management system, without disrupting their day-to-day operations too much.

Any conclusive pointers/examples/tutorials to get this done server side would be greatly appreciated.

Answer 1

I'm not sure how well S3 aligns with OneDrive, they are quite different models. OneDrive is provisioned by user which begs the question, which user would you want to copy this file too? I would think Azure Storage would be a far better fit as it uses a similar model to S3.

You can use Microsoft Graph API to upload the file to a user's OneDrive . You would need to authenticate the user in order to obtain an Access and Refresh Token. Once this process is done, you can store that Refresh Token and retrieve an updated Access Token as needed.

Answer 2

Also with CloudRail it's necessary to authenticate the user, but there are methods to store and use an access token.

The services have two methods, loadAsString and saveAsString, and they are used to store and load credentials. You could call loadAsString with your access token, the string can be different from service to service, but will look something like this: [{“access_token”: “YOUR ACCESS TOKEN”}]

Answer 3

To add to this, Microsoft now has a cloud migration tool www.mover.io that allows you to sync files & folders from most clouds into Azure blob, Sharepoint or OneDrive directly, so without download/upload to a client machine.

Personally used it only for a one-time sync, but leaving it here for posterity.

Answer 4

The client only has to login once so if you already have the client and secret keys, you can do the manual flow once then save the generated token file together with your code files in AWS. Next time the code is ran, it uses the refresh token. Last time I did this I was able to set the refresh token to never expire but I think Microsoft has randomly removed that option and now the token can only last something like 2 or 3 years max