Proposal: Support multipart/form-data in the watchdog

[johnmccabe]

Expected Behaviour

I would like to be able to send multipart/form-data to a function and have the parts in that form-data exposed to the function in a json object.

For example:

curl localhost:8080/function/myfn -F "image=@picture.jpg" -F "text=@README.md" -F "somekey=somevalue"

Would result in the following map being passed to the function (expect this to be packaged up with the headers similarly to when marshalRequest is set).

key	value	encoded	filename
image	CpLjQJx3/...	true	picture.jpg
text	#README Title...	false	README.md
somekey	somevalue	false

Where binary Mime types are base64 encoded prior to marshalling.

Current Behaviour

Its currently not straight forward to pass multiple files to a function, adding the ability to use multipart/form-data with JSON can simplify the process.

Possible Solution

I've a working prototype on a local branch that I'd implemented to allow me to create a demo function for a Meetup today.

Steps to Reproduce (for bugs)

n/a

Context

I want a simple way of passing multiple files to a function, ideally via curl for inclusion in CI pipelines with minimal overhead.

Your Environment

• Docker version docker version (e.g. Docker 17.0.05 ):
  17.09.0-ce
• Are you using Docker Swarm or Kubernetes (FaaS-netes)?
  Swarm
• Operating System and version (e.g. Linux, Windows, MacOS):
  MacOS 10.12.6
• Link to your project or a code example to reproduce issue:
  Will raise PR

[johnmccabe]

Derek add label: proposal

[alexellis]

/close: inactive