feat: Python MQTT UDSource, Fixes #3061

[SaniyaKalamkar]

Fixes numaproj/numaflow#3061. Creates MQTT UDSource that subscribes to an MQTT broker and emits messages into Numaflow pipelines.

Added mqtt_udsource.py, main MQTT UDS implementation.
Added requirements.txt for Python dependencies
Added Dockerfile for container image

[vigith]

Could you please add a pipeline.yaml for running this?

[vigith]

thank you.. how did you deploy the mqtt in k8s? was it a deployment? if yes, do you mind putting that manifest too?

[SaniyaKalamkar]

Yeah, deployed using Mosquitto MQTT broker. I created a ISB service, created docker container and loaded into k8s, deployed Mosquitto, deployed pipeline, then sent test messages and checked logs. Let me know if you need any more details.

[vigith]

Can you add a README.md file to explain this? also, move the .yaml files to a sub-dir called manifest.

[SaniyaKalamkar]

Yeah of course, sounds good.

[vigith]

Lastly, please document how to send some data to the MQTT brokers so users can experiment by sending test messages.

[vigith]

This will create dummy payloads which is not right. You do not have to return anything if there is no data. In the README, just add how you can send some data to MQTT broker via command-line.

{"timestamp":"2025-11-17T00:23:16.613066Z","level":"INFO","message":"Payload - dummy-669498 Keys -  EventTime - 1763338996579 Headers - x-txn-id: 9cac40fb-4c59-4df1-ac23-d77128c2105d,  ID - log-sink-669499-0-0","target":"numaflow_core::sinker::sink::log"}
{"timestamp":"2025-11-17T00:23:16.613068Z","level":"INFO","message":"Payload - dummy-669499 Keys -  EventTime - 1763338996579 Headers - x-txn-id: 6a429484-9fb6-4342-ad72-d598499f413f,  ID - log-sink-669500-0-0","target":"numaflow_core::sinker::sink::log"}