Improve subscriber handling content distribution response

[shafreenAnfar]

The spec says

Subscribers SHOULD respond to content distribution requests as quickly as possible; their success response code SHOULD only indicate receipt of the message, not acknowledgment that it was successfully processed by the subscriber.

For more information see https://www.w3.org/TR/websub/#content-distribution

I wonder if we should change the default behavior to automatically handle it internally and send 2xx response when the content is received. This can be disabled if the user wants via a configuration.

[shafreenAnfar]

@ayeshLK @chamil321 any thoughts ?

[shafreenAnfar]

I think as per the current behavior, the ideal code should be something like the below,

import ballerina/websub;
import ballerina/io;

@websub:SubscriberServiceConfig {
    target: [
        "https://api.github.com/hub", 
        "https://github.com/<YOUR_ORGANIZATION>/<REPOSITORY>/events/push.json"
    ],
    secret: "<YOUR_SECRET_KEY>",
    httpConfig: {
        auth: {
            token: "<YOUR_AUTH_TOKEN>"
        }
    }
}
service /JuApTOXq19 on new websub:Listener(9090) {
    remote function onEventNotification(
                    websub:ContentDistributionMessage event) {
        worker A returns error? {
            var retrievedContent = event.content;
            if retrievedContent is json {
                // body
            } else {
                io:println("Unrecognized content type, hence ignoring");
            }
        }
    }
}

[ayeshLK]

I wonder if we should change the default behavior to automatically handle it internally and send 2xx response when the content is received. This can be disabled if the user wants via a configuration.

This seems a good improvement to websub:SubscriberService.

[chamil321]

+1

• Better user experience (Error prevention)
• Hub retry effort also will get reduced in the case of not responding mistakenly to the receipt of content by the user.