Building Real-time Systems with WebSub - Ballerina Community Call - 11/30/2021
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During this call, we will present: - A quick overview of WebSub protocol and the current Ballerina WebSub framework - Real-world use case and demonstration
Building Real-time Systems with WebSub - Ballerina Community Call - 11/30/2021
- 1. Community Call - November 2021 Building Real-Time Systems with WebSub
- 2. In this presentation Quick Overview of WebSub Protocol Real-world Use Case of WebSub Ballerina WebSub Framework
- 3. Open Protocol for distributed pub/sub communication. Based on HTTP webhooks. Main Roles: Publisher Subscriber Hub Speci鍖cation: https://www.w3.org/TR/websub/ What is WebSub ?
- 4. WebSub Cont
- 5. Use Case: News Hub Scenario News Hub is a centralized location to which the local journalists and News channels connect. Journalists will publish the news updates to the News Hub. News Hub will then distribute the updates to the News channels who are subscribed to the news feeds of the journalist.
- 7. Demo
- 8. Ballerina WebSub In Ballerina, WebSub implementation is divided into two packages: WebSub: Subscriber WebSubHub: Hub Publisher
- 9. Ballerina WebSub: Hub API public type Service distinct service object { // Sample POST request hub.mode=register&hub.topic=http://foo.com/bar // Sample 200 OK response hub.mode=accepted or 200 OK hub.mode=denied&hub.reason=unauthorized remote function onRegisterTopic(websubhub:TopicRegistration msg) returns websubhub:TopicRegistrationSuccess|websubhub:TopicRegistrationError|error; // Sample POST request hub.mode=unregister&hub.topic=http://foo.com/bar // Sample 200 OK response hub.mode=accepted or 200 OK hub.mode=denied&hub.reason=unauthorized remote function onDeregisterTopic(websubhub:TopicDeregistration msg) returns websubhub:TopicDeregistrationSuccess|websubhub:TopicDeregistrationError|error; // Sample POST request with content type x-www-form-urlencoded hub.mode=publish&hub.topic=http://foo.com/bar // for other content types such as xml, json and octect-stream hub.mode=publish should be in query string. // Sample 200 OK response hub.mode=accepted or 200 OK hub.mode=denied&hub.reason=unauthorized remote function onUpdateMessage(websubhub:UpdateMessage msg) returns websubhub:Acknowledgement|websubhub:UpdateMessageError|error; // Sample POST request hub.mode=subscribe&hub.topic=http://foo.com/bar remote function onSubscription(websubhub:Subscription msg) returns websubhub:SubscriptionAccepted|websubhub:SubscriptionPermanentRedirect|websubhub:SubscriptionTemporaryRedirect| websubhub:BadSubscriptionError|websubhub:InternalSubscriptionError|error; remote function onSubscriptionValidation(websubhub:Subscription msg) returns websubhub:SubscriptionDeniedError|error?; remote function onSubscriptionIntentVerified(websubhub:VerifiedSubscription msg) returns error?; // Sample POST request hub.mode=unsubscribe&hub.topic=http://foo.com/bar remote function onUnsubscription(websubhub:Unsubscription msg) returns websubhub:UnsubscriptionAccepted|websubhub:BadUnsubscriptionError|websubhub:InternalUnsubscriptionError|error; remote function onUnsubscriptionValidation(websubhub:Unsubscription msg) returns websubhub:UnsubscriptionDeniedError|error?; remote function onUnsubscriptionIntentVerified(websubhub:VerifiedUnsubscription msg) returns error?; }
- 10. WebSub Speci鍖cation: https://www.w3.org/TR/websub/ Ballerina WebSub Libraries: WebSub WebSubHub Hub Sample: https://github.com/ballerina-platform/module-ballerina-websubhub/tree/ main/examples/kafka-hub References
- 11. Questions?
- 12. Thank you!