Adding extension for OPC UA

[koepalex]

Fixes #

OPC UA is a commonly used IEC standard for industrial communication. It support reading data from shopfloor devices like Programmable logical controller, SCADA systems, MES system and others. Those data can be read and processed on edge devices are forwarded to an downstream datacenter or cloud. Routing is essential to direct the the process data value changes or events or meta data the right way.

Proposed Changes

• Map OPC UA PubSub defined network and dataset message headers to cloud events attributes
• Use existing Cloud events extension to map additional fields from network and dataset message headers
• Define own OPC UA specific Cloud Event attributes

Release Note

We are thrilled to announce the release of the OPC UA Extension for Cloud Events. This streamlined extension focuses exclusively on OPC UA PubSub, enhancing communication between OPC UA and cloud-based systems.

[duglin]

Hi @koepalex
Couple of things:

• can you sign your commits?
• can you add a file like this one: https://github.com/cloudevents/spec/blob/main/cloudevents/languages/he/extensions/authcontext.md that is just a placeholder for the Hebrew translation. You should be able to just ignore the non-English stuff and replace the link with yours

[duglin]

Feedback from today's weekly call - from @markpeek - would it be possible to add some examples or guidance for how this would look in practice? Just to help people understand how the two worlds come together in practice. Example tend to help new folks a lot. And perhaps some text around how CE will help OPC UA use case?

[duglin]

No initial concerns raised on today's call. All - please review for vote on next week's call.

[koepalex]

Feedback from today's weekly call - from @markpeek - would it be possible to add some examples or guidance for how this would look in practice? Just to help people understand how the two worlds come together in practice. Example tend to help new folks a lot. And perhaps some text around how CE will help OPC UA use case?

I have extended the extension with examples of how CloudEvent attributes would look like, and tried to explain the use cases as well as the benefits.

I also changed the subject for ua-events from EventId to DataSetWriterName/EventIdto avoid loosing the context (Same event can be raised for different DataSetWriter.

[koepalex]

Remark: as Friday and Monday are public holiday for me, I will address all new review comments starting Tuesday.

[duglin]

ping @markpeek to see if the samples address his ask

[duglin]

thanks!

[duglin]

Approved on the 4/4 call