The `from_http` returns CloudEvent with inaccessible attributes

Expected Behavior

The from_http function should return a CloudEvent object where attributes like specversion, type, and source are accessible via event["attributes"] or similar documented methods.

Actual Behavior

But for me the from_http function returns a CloudEvent object with an empty attributes field. Attempting to access specversion, type, or source returns missing.

Steps to Reproduce the Problem

1. Save the following script as reproducer.py:

import logging
from cloudevents.http import from_http
from http.server import BaseHTTPRequestHandler, HTTPServer

logging.basicConfig(level=logging.DEBUG)

class CloudEventHandler(BaseHTTPRequestHandler):
    def do_POST(self):
        headers = {key.lower(): value for key, value in self.headers.items()}
        content_length = int(self.headers.get("content-length", 0))
        body = self.rfile.read(content_length).decode("utf-8")

        logging.info(f"Received headers: {headers}")
        logging.info(f"Received body: {body}")

        try:
            event = from_http(headers, body)
            logging.info(f"Parsed CloudEvent: {event}")

            logging.info(f"Type of parsed event: {type(event)}")
            logging.info(f"Event attributes: {event.get('attributes', {})}")

            specversion = event.get("attributes", {}).get("specversion", "missing")
            event_type = event.get("attributes", {}).get("type", "missing")
            source = event.get("attributes", {}).get("source", "missing")

            logging.info(f"Specversion: {specversion}, Type: {event_type}, Source: {source}")

            response_body = {
                "specversion": specversion,
                "type": event_type,
                "source": source,
            }

            self.send_response(200)
            self.send_header("Content-Type", "application/json")
            self.end_headers()
            self.wfile.write(str(response_body).encode("utf-8"))

        except Exception as e:
            logging.error(f"Error parsing CloudEvent: {e}")
            self.send_response(500)
            self.end_headers()
            self.wfile.write(f"Error: {e}".encode("utf-8"))

def run(server_class=HTTPServer, handler_class=CloudEventHandler, port=8080):
    server_address = ("", port)
    httpd = server_class(server_address, handler_class)
    logging.info(f"Starting HTTP server on port {port}")
    httpd.serve_forever()

if __name__ == "__main__":
    run()

2. Run the script via python reproducer.py

3. Access the server, like:

curl -v -X POST \
    -H "Content-Type: application/json" \
    -H "ce-specversion: 1.0" \
    -H "ce-type: test.event.type" \
    -H "ce-source: /my/source" \
    -H "ce-id: 12345" \
    -d '{"key":"value"}' \
    http://127.0.0.1:8080

4. See the logs:

INFO:root:Received headers: {'host': '127.0.0.1:8080', 'user-agent': 'curl/8.9.1', 'accept': '*/*', 'content-type': 'application/json', 'ce-specversion': '1.0', 'ce-type': 'test.event.type', 'ce-source': '/my/source', 'ce-id': '12345', 'content-length': '15'}
INFO:root:Received body: {"key":"value"}
INFO:root:Parsed CloudEvent: {'attributes': {'specversion': '1.0', 'id': '12345', 'source': '/my/source', 'type': 'test.event.type', 'datacontenttype': 'application/json', 'time': '2024-12-19T09:29:20.297551+00:00'}, 'data': {'key': 'value'}}
INFO:root:Type of parsed event: <class 'cloudevents.http.event.CloudEvent'>
INFO:root:Event attributes: {}
INFO:root:Specversion: missing, Type: missing, Source: missing

Specifications

• Platform: Linux (Fedora release 41)
• Python Version: Python 3.13.0
• SDK-Version: via pip show cloudevents:

Name: cloudevents
Version: 1.11.0
Summary: CloudEvents Python SDK
Home-page: https://github.com/cloudevents/sdk-python
Author: The Cloud Events Contributors
Author-email: cncfcloudevents@gmail.com
License: https://www.apache.org/licenses/LICENSE-2.0
Location: /home/<user-name>/.local/lib/python3.13/site-packages
Requires: deprecation
Required-by: 

首先使用提供的 reproducer.py 脚本复现该行为，并检查 from_http 入口点和 cloudevents.http.event.CloudEvent 表示。验证解析后的属性应如何访问，然后确保文档中说明的访问方法公开 specversion、type 和 source，并通过回归检查确认该行为。