How to serve multiple routes on the same Url : Port

[martindufort]

Hi,

I'm trying to serve multiple routes from the same Host / Port combination for local testing.

Each of these routes would point to a specific target.
All cloud functions (on GCloud) are sharing the same hostname.
So I would like to replicate this environment as much as possible

Is this possible ? I have not seen anything in the documentation to help me perform this setup.
I would like to serve something like this:

http://localhost:8080/doFunctionA
http://localhost:8080/doFunctionB
http://localhost:8080/doFunctionC

Thanks

[di]

Hi @martindufort, thanks for filing an issue.

If I understand correctly, you have multiple individual functions and you'd like to be able to serve them all simultaneously. You do not have a single function that you're trying to serve multiple endpoints from, is that correct?

If so, you're correct that the Functions Framework doesn't currently support that, but I think it would probably be a reasonable feature request. How would you imagine invoking the framework with multiple targets?

[di]

Also, a follow-up question: are these all the same function type, or are they a mix of HTTP and Background functions?

[martindufort]

Hi @di, thanks for the quick reply.

A little bit of background: We have a server component to our solution which is being managed by the GCloud API Gateway connected to a number of cloud functions (http-triggered)

Within our Openapi description document, each route (URL Path) is directed to a specific Cloud Function.

paths:
  /account/make:
    post:
      operationId: makeAccount
      x-google-backend:
        address: https://us-central1-xxxx.cloudfunctions.net/makeAccount

When we deploy them, they are all accessible from the same host but with a specific URL path.

So I would like to have a similar configuration for local testing where we would serve all these functions simultaneously on the same host:port combination.

Then we will be able to mimic the API Gateway functionality and test those locally.

For the configuration, I was thinking we could supply a .yaml file that would describe the mapping between the URL-Path and the (source file/target function) locally.

Let me know if this is clear enough.

[di]

Thanks for the replies @martindufort! Makes sense.

This is probably not something the Function Frameworks will support directly, however I created #99 to show an example of using skaffold, minikube, Cloud Buildpacks, and the Function Framework to run multiple functions on the same host and route based on some path.

I think this should satisfy your use case, please take a look and let me know!

[martindufort]

Hi @di, I had a look at #99 and it looks good.
However this is involving too many external dependencies for us. And we want to manage them at a minimum.

We might try to fork and change some of the functionality to provide a lighter mechanism for our needs.
Will report back if we go that route.

Thanks for your reply.

[av1m]

I think you can bypass using this method, an example :

# main.py
from flask import Flask, request

app = Flask(__name__)


@app.route("/", methods=["GET"])
def main():
    return "<h1>Hello World</h1>", 200


@app.route("/user/<string:id>", methods=["POST", "GET"])
def user(id):
    if request.is_json:
        return {"id": id, **request.json}, 200
    return {"id": id}, 200


def entrypoint(request):
    # Create a new app context for the app
    internal_ctx = app.test_request_context(
        path=request.full_path, method=request.method
    )
    # Copy the request headers to the app context
    internal_ctx.request = request
    # Activate the context
    internal_ctx.push()
    # Dispatch the request to the internal app and get the result
    return_value = app.full_dispatch_request()
    # Offload the context
    internal_ctx.pop()
    # Return the result of the internal app routing and processing
    return return_value

Run this script with the following command :

functions_framework --target entrypoint

You can also see this example with blueprints https://github.com/av1m/functions-multiple-endpoints.git