Feature Request: Add pipenv support

[jblakeney]

Can support be added for using pipenv and Pipfile for resolving dependancies and building instead of the common pip and requirements.txt method.

[jfuss]

Updated title to match what the description said. Pipenv instead of pyenv

[AlanFoster]

Just for context; Is this project currently being used by the sam cli build functionality?

I can't quite see where aws-sam-cli is connected to this project, but I can see from the read me that this work is maybe in flight? 🤔

We are in the process of implementing this project.

[jblakeney]

The aws-sam-cli uses this project to define how to build and package dependencies when running sam build.

There is probably a reference in the code somewhere (been a while since I looked at it), but you can see its referenced in the base.txt as a dependency.

https://github.com/awslabs/aws-sam-cli/blob/develop/requirements/base.txt

[billyshambrook]

We currently have a Makefile which will does the old pipenv lock -r > requirements.txt && sam build --manifest requirements.txt dance. Would like to try and work on this issue so we can all avoid doing that :)

There's a couple of questions I have around the implementation though:

1. I see with the pip workflow, it's not just as simple as pip install -r requirements.txt, but instead there is a long module that is figuring out the dependencies. With pipenv, is this needed, or can we just do pipenv install? If we can't just use pipenv install, should we output the requirements.txt from pipenv and pass it to that module? Here's the module I'm talking about - https://github.com/awslabs/aws-lambda-builders/blob/develop/aws_lambda_builders/workflows/python_pip/packager.py

2. I see aws-toolkit-vscode currently expects there to be a requirements.txt for it to add ptvsd to when debugging. Do we need to consider this, or is this something that aws-toolkit-vscode will have to handle?

Thanks

[symroe]

@billyshambrook as pipenv basically wraps pip it seems reasonable to have a pipenv workflow here that mostly wraps / extends the pip workflow. A quick win would be to basically push the pipenv lock -r > requirements.txt into a builder and then call the pip workflow with the output.

I've never worked on this project, but looking at it, it doesn't seem like a massive job. I'm willing to have a crack, but could do with some advice on if the above is a good idea or not.