opengeospatial / pubsub

PubSub Standard Working Group (SWG)

Welcome to the OGC PubSub SWG GitHub Repo.

The PubSub Standards Working Group (SWG) is working under the auspices of the Open Geospatial Consortium. The purpose of this SWG is to develop Best Practices and potentially Standards for utilizing Publish-Subscribe protocols in OGC Web APIs.

Draft PubSub Specifications

To be determined

Contributing

The OGC PubSub SWG is the group at OGC responsible for the stewardship of these publications. As of our publication to this repo, the SWG will do as much work in public as possible.

If you have input, comments or feedback for the SWG’s consideration, please begin by reviewing the open issues tab. If there is already an issue with your question, concern or input, please respond or discuss in the issue. If your input, feedback or question is new (not captured in a prior issue), please open a new issue.

The PubSub SWG will promptly review open issues and address or reply to new issues in a timely manner.

If necessary, make a branch from the "working" branch of this repo. Make any changes to your own branch of "working" Pull Requests from contributors may only be made on the "working" branch. Please note that by sending a Pull Request or Commit to this GitHub repository, you are agreeing to the terms in the [OGC PubSub SWG Observer Agreement].

The contributor understands that any contributions, if accepted by the OGC PubSub SWG, shall be incorporated into a final OGC document and that all copyright and intellectual property shall be vested to the OGC. See Copy of OGC License Language.

pubsub's Issues

Advertising channel endpoints in a future Pub/Sub conformance class

During the April 2023 code sprint, a need was identified to be able to advertise MQTT channels on a collection metadata response. An example fragment is shown below.

        {
            "type": "application/json",
            "rel": "items",
            "title": "Subscription information (Pub/Sub)",
            "href": "mqtt://localhost:1883",
            "channel": "collections/weather-observations"
        } 

There is clearly a need to be able to include additional parameters in links. Since RFC 8288 identifies a specific set of link-params that are allowed in links, does that mean that no other link-params are allowed?

If so, how might we address the need to advertise channel endpoints in a future Pub/Sub conformance class of OGC API Standards.

Use of AsyncAPI in PubSub

Should the use of AsyncAPI be mandated to describe the PubSub facilities?
E.g: An OGC API SHALL provide the description of its Publish-Subscribe capabilities using AsyncAPI to describe supported protocols, channels and message payload descriptions.

As far as I know, AsyncAPI can describe the various likely candidate protocols such as MQTT, AMQP, etc., so I am in favour if keeping it simple, as above.

OGC API Common Part 1: Core, clause 6.6.2 states a looser requirement for OpenAPI:-
This OGC API Standard uses OpenAPI 3.0 fragments in examples and to formally state requirements. Using OpenAPI 3.0 is not required for implementing an OGC API. Other API definition languages may be used along with, or instead of, OpenAPI. However, any API definition language used should have an associated conformance class advertised through the / conformance path. This Standard includes a conformance class for OGC API definitions that follow the OpenAPI specification 3.0. Alternative API definition languages are also allowed. Conformance classes for additional API definition languages will be added as the OGC API landscape continues to evolve.

Original PubSub Charter

The OGC Portal does not seem to have a copy of the original PubSub Standard Working Group Charter. We need a copy on this repo so we can revise.