Subscribe to Multiple Applications in Single MQTT Connection

[htdvisser]

Summary

It would be really cool if we could subscribe to multiple applications in a single MQTT connection.

Why do we need this?

Simplification

What is already there? What do you see now?

MQTT sessions are per-application

What is missing? What do you want to see?

It may not be necessary to have this restriction.

How do you propose to implement this?

• On CONNECT only verify that the auth (API key) is valid
• On SUBSCRIBE verify that the auth has read access to the application in the topic filter
  • This requires the SUBSCRIBE to explicitly contain the application ID, so no wildcards.
• On PUBLISH verify that the auth has write access to the application in the topic

Can you do this yourself and submit a Pull Request?

I can investigate and make a proposal. Definitely something for the longer term though.

[GMouaad]

Is it possible in the future to enable the Stack Owner (the admin) to subscribe to all topics. Or is there anything that speaks against it? I can imagine that an argument would be the data ownership.

[htdvisser]

Removing my assignment. If there are more users that would like to see this functionality, please react with a 👍 vote on the issue, so that we can track demand from the community.