The Mirabelle Websocket server allows user to subscribe to channels.
This guide uses the [https://github.com/appclacks/cl](Appclacks CLI) to interact with Mirabelle.
(streams
(stream {:name :bar :default true}
(where [:= :service "bar"]
(publish! :my-channel))))
In this stream, we filter all events with :service “bar”, then we publish them to a channel named :my-channel.
Users then subscripe to those channels. In this example, all users subscribing to the :my-channel channel will receive the events.
You can test that yourself by running the appclacks mirabelle subscribe --channel my-channel command. You can then send an event to Mirabelle (mirabelle event send --name http_requests_duration_seconds --metric 1 --service bar) and it should be displayed by the subscribe command.
When you subscribe to a channel, you should provide a valid where clause in base64. For example, the query [:> :metric 10] which matches everything would be Wzo+IDptZXRyaWMgMTBd. The CLI will do the conversion for you: appclacks mirabelle subscribe --channel my-channel --query '[:> :metric 10]' will keep only events with the metric field greater than 10.
You can also write your own scripts in various languages. You need to subscribe to ws://<host>:<port>/channel/<channel-name>?query=<query>.