http-containerize

Function framework for Python

This framework provides a mechanism to write Function-as-a-Service style code in Python for handling HTTP events, including CloudEvents delivered via HTTP.

This framework is primarily intended to work with Knative, but also works to provide a generic server for handling CloudEvents over HTTP (e.g. from Kubernetes or on a local machine).

The framework uses reflection to find a suitable function to wrap; it should not be necessary to import any of the following modules in your own code unless you want (e.g. for type definitions):

• frameork (this module; on PyPi as http-containerize)
• flask
• cloudevents

Instead, simply ensure that you have a single non-_ prefixed function which uses some combination of the following:

• HTTP request arguments (named req, request, body, headers or of the flask.Request type)
• CloudEvent arguments (named event, payload, data, attributes or of the cloudevents.sdk.event.v1.Event type)

Usage:

import logging
from typing import Any


counter = 0


def DoEvent(data: Any, attributes: dict, req: Any):
    global counter
    counter = counter + 1

    logging.info(f"Got data: {data}")
    logging.info(f"From {req.origin}, my {counter}th request!")

    attributes["type"] = "com.example.reply"
    attributes["datacontenttype"] = "text/plain"

    return attributes, "It's a demo"

Building into a container:

You can use the packeto buildpacks if you add http-containerize>=0.4.0 to your requirements.txt:

pack build pytestapp --buildpack  ekanderson/pyfun:0.1.1 --builder paketobuildpacks/builder:base

You can then invoke it via:

docker run --rm -p 8080:8080 -e 8080 pytestapp