How do I send a file upload from an HTML form to S3 via PHP without local storage?

Question

I'm trying to convert a website to use S3 storage instead of local (expensive) disk storage. I solved the download problem using a stream wrapper interface on the S3Client. The upload problem is harder.

It seems to me that when I post to a PHP endpoint, the $_FILES object is already populated and copied to /tmp/ before I can even intercept it!

On top of that, the S3Client->upload() expects a file on the disk already!

Seems like a double-whammy against what I'm trying to do, and most advice I've found uses NodeJS or Java streaming so I don't know how to translate.

It would be better if I could intercept the code that populates $_FILES and then send up 5MB chunks from memory with the S3\ObjectUploader, but how do you crack open the PHP multipart handler?

Thoughts?

EDIT: It is a very low quantity of files, 0-20 per day, mostly 1-5MB sometimes hitting 40~70MB. Periodically (once every few weeks) a 1-2GB file will be uploaded. Hence the desire to move off an EC2 instance and into heroku/beanstalk type PaaS where I won't have much /tmp/ space.

user_1994251 · Answer

It's hard to comment on your specific situation without knowing the performance requirements of the application and the volume of users needed to access it so I'll try to answer assuming a basic web app uploading profile avatars.

There are some good reasons for this, the file is streamed to the disk for multiple purposes one of which is to conserve memory use. If your file is not on the disk than it is in memory(think disk usage is expensive? bump up your memory usage and see how expensive that gets), which is fine for a single user uploading a small file, but not so great for a bunch of users uploading small files or worse: large files. You'll likely see the best performance if you use the defaults on these libraries and let them stream to and from the disk.

But again I don't know your use case and you may actually need to avoid the disk at all costs for some unknown reason.

How do I send a file upload from an HTML form to S3 via PHP without local storage?

1 Answers