Step-through debugging in VSCode with Postman

[brandon-burciaga]

System details (run the AWS: About Toolkit command)

OS: Linux x64 5.10.16.3-microsoft-standard-WSL2
Visual Studio Code extension host: 1.78.2
AWS Toolkit: 1.72.0
node: 16.17.1

Question

So I understand I can invoke Lambdas locally in various ways. All of these ways consist of sending a payload and the debugging session only lasts for one request cycle.

I'd love to be able to start the APIG instance with sam local start-api and be able to step-through debug while hitting the API from Postman.

It seems this just isn't possible?

I have tried using a combination of sam local start-api -d 5858 and configuring my VSCode launch.json to attach to port 5858, however this does not work as expected.

Any advice or guidance here? With Azure Functions, I can just press F5 and everything works as expected...

[justinmk3]

This is definitely something we want to enable! Does #2535 match what you expect?

With Azure Functions, I can just press F5 and everything works as expected...

Meaning, it opens a port? Or does Azure Functions extension do something specific with postman?

[brandon-burciaga]

@justinmk3 yes this is exactly what I am looking for. To be able to use sam local start-api to launch a sustained/running instance of the local API, and attach the VSCode debugger to it. Then I can make Postman or cURL requests ad hoc while the SAM server continues to run/host the API. I would be fine with either having to run sam local start-api in a terminal, and then starting the debugger, or having the debugger itself start the api.

Everything for Lambdas seem to just execute the function once, then the debugger stops. It would be great to be able to ad-hoc requests like I mentioned.

As for Azure, it does open a port and list the endpoints available at localhost. It doesn't do anything with Postman, I am just using that as an example since our APIs are in Postman. cURL could be used as an example instead.

Here is an example Azure Function launch.json:

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "Attach to Node Functions",
      "type": "node",
      "request": "attach",
      "port": 9230,
      "preLaunchTask": "func: host start"
    }
  ]
}

I am wanting to be able to do something similar with my Lambdas.

[scottattern]

@justinmk3 - this is exactly what we need if we can get an ETA or workaround

[brandon-burciaga]

@justinmk3 do you have any ideas where to start with this?