Firehose is an embedded MQTT broker that concentrates events from services run within a Software Factory deployment, making it easy for external processes to consume these events and act upon them.

It is not possible to publish messages on the firehose outside of the predefined services, however anyone is allowed to subscribe anonymously to the feed by using the MQTT protocol.

Services supported

Service Topic Source
Gerrit gerrit germqtt
Zuul zuul reporter

Events published

Events are published in JSON format. The payload is specific to each event.


Every patchset-related events are published, similarly to the gerrit stream-events command. A full description of each event type can be found here:


Every buildset results are published. A full description of the events can be found here:

Subscribing to events

Simple CLI example

The mosquitto project provides a CLI subscriber client that can be used to easily subscribe to any topic and receive the messages. On debian based distributions it is included in the mosquitto-clients package; on Fedora or CentOS it can be found in the mosquitto package. For example, to subscribe to every topic on the firehose you would run:

mosquitto_sub -h firehose.fqdn --topic '#'

You can adjust the value of the topic parameter to subscribe only to a specific service.

Simple desktop notifier

If you are using a GTK based desktop environment such as gnome, this script can be used to get notifications on specific, customizable events from the firehose:;a=summary

Please see the project’s README for more information.